HEMATOPATHOLOCentral Nervouss System Infections GY2014.pptx

Central Nervouss System Infections

1. The Haematopoietic System AnEMIA

2. ANAEMIA IS DEFINED AS A HAEMOGLOBIN CONCENTRATION IN BLOOD BELOW THE LOWER LIMIT OF THE NORMAL RANGE FOR THE AGE AND SEX OF THE INDIVIDUAL . ANEMIA CAN ALSO BE DEFINED AS THE REDUCTION IN THE OXYGEN CARRYING CAPACITY OF THE BLOOD, WHICH IS USUALLY DUE TO REDUCTION OF THE TOTAL CIRCULATING RED CELL MASS .

3. The lower extreme of the normal haemoglobin is taken as 13.0 g/dl for males and 11.5 g/dl for females. Measurement (units) Men WOMEN HEMOGLOBIN(gm/dl 13.6–17.2 12.0–15.0 Hematocrit (%) 39-49 33-43 Red cell count (10⁶ / μL ) 4.3-5.9 3.5- 5.0 Reticulocyte count (%) 0.5-1.5 0.5-1.5 Mean cell volume ( μ m3) 82-96 82-96 Mean corpuscular hemoglobin (pg) 27-33 27-33 Mean corpuscular hemoglobin concentration (gm/ dL ) 33-37 33-37 RBC distribution width 11.5-14.5 11.5-14.5

4. CLINICAL FEATURES OF ANEMIA symptoms and signs of anaemia depends upon 4 main factors: 1 . The speed of onset of anaemia 2 . The severity of anaemia 3 . The age of the patient 4. Hemoglobin dissociation curve

5. SYMPTOMS The presenting features are: tiredness, easy fatiguability , generalized muscular weakness, lethargy and headache. SIGNS 1 . Pallor. 2 . Hyperdynamic circulation 3. Attacks of faintness 4 . Retinal haemorrhages 5. Menstrual disturbances 6 . Mild proteinuria 7. Anorexia, flatulence

6. INVESTIGATIONS NECESSARY FOR CONFIRMATION OF ANEMIA HEMOGLOBIN ESTIMATION. PERIPHERAL BLOOD EXAMINATION : LOOK FOR RBC CHANGES LIKE--1.VARIATION IN SIZE(ANISOCYTOSIS) 2.VARIATION IN SHAPE(POIKILOCYTOSIS) 3.INADEQUATE Hb FORMATION COMPENSATORY ERYTHROPOIESIS WBC AND PLATELET COUNT RETICULOCYTE COUNT ERYTHROCYTE SEDIMENTATION RATE(ESR) BONE MARROW EXAMINATION

7. CLASSIFICATION OF ANEMIA A-BLOOD LOSS -ACUTE: TRAUMA -CHRONIC: GIT AND GYNECOLOGIC LESIONS B- INCREASED DESTRUCTION OF RBC ( Hemolytic Anemias ). - INTRINSIC CAUSE HEREDITARY 1.MEMBRANE ABNORMALITIES EX.SPHEROCYTOSIS, ELLIPTOCYTOSIS 2.ENZYME DEFICIENCIES EX.G6PD,PYRUVATE KINASE, 3.DISORDERS OF HEMOGLOBIN SYNTHESIS EX.THALASSEMIA SYNDROMES(DEFICIENT GLOBIN SYNTHESIS) SICKLE CELL ANEMIA(STRUCTURALLY ABNORMAL GLOBIN SYNTHESIS) BASED ON PATHOPHYSIOLOGIC MECHANISMS

8. ACQUIRED -MEMBRANE DEFECT EX.PARAXYSMAL NOCTURNAL HEMOGLOBINURIA EXTRINSIC ABNORMALITIES -ANTIBODY MEDIATED EX.TRANSFUSION REACTIONS,Rh DISEASE OF THE NEWBORN -AUTOANTIBODIES EX.IDIOPATHIC,SLE,DRUG INDUCED -MECHANICAL TRAUMA TO THE RBCs EX.MICROANGIOPATHIC HEMOLYTIC ANEMIA,DIC -INFECTIONS EX.MALARIA

9. C-IMPAIRED RED CELL PRODUCTION i -DEFECTIVE HEMOGLOBIN SYNTHESIS EX.DEFECTIVE HEME SYNTHESIS: IRON DEFICIENCY DEFECTIVE GLOBIN SYNTHESIS: THALASSEMIA ii -NUCLEAR MATURATION DEFECTS EX.VITAMIN B12 AND FOLIC ACID DEFICIENCY iii-DEFECT IN STEM CELL PROLIFERATION AND DIFFERENTIATION EX. APLASTIC ANEMIA,PURE RED CELL APLASIA D- ANEMIA OF CHRONIC DISORDERS E- CONGENITAL ANEMIA F- BONE MARROW INFILTRATIONS LEADING TO ANEMIA

10. CLASSIFICATION OF ANEMIA MORPHOLOGIC MACROCYTIC HYPOCHROMIC NORMOCYTIC NORMOCHROMIC MICROCYTIC HYPOCHROMIC

11. MICROCYTIC HYPOCHROMIC ANEMIA Iron deficiency is the commonest cause of microcytic hypochromic anaemia the world over . It is estimated that about 20% of women in child-bearing age group are iron deficient, while the overall prevalence in adult males is about 2%. All the three red cell indices (MCV, MCH and MCHC) are reduced in this anemia.

12. Pathogenesis of iron deficiency anemia When the supply of iron to the marrow becomes insufficient for haemoglobin formation, iron deficiency anaemia develops. Causative factors: Increased blood loss: eg.Excess menstrual loss,repeated miscarriages,post menopausal bleeding,peptic ulcer,oesophageal varices , carcinoma stomach and colon,hemoptysis , hemetemesis,epistaxis,hematuria,hemorrhoids . Increased requirements: during infancy,childhood puberty,pregnancy and lactation Inadequate dietary intake: malnutrition,anorexia , poor economic status,pregnancy . Decreased absorption:Malabsorption,partial or total gastrectomy , achlorhydria

13. CLINICAL FEATURES 1. Anaemia . Weakness, fatigue, dyspnea on exertion, palpitations and pallor of the skin, mucous membranes and sclerae . Older patients may develop angina and congestive cardiac failure. 2. Epithelial tissue changes. The changes occur in the nails ( koilonychias or spoon-shaped nails), tongue (atrophic glossitis ), mouth (angular stomatitis ), and oesophagus causing dysphagia

14. Koilonychia & angular stomatitis and atrophic glossitis

15. Laboratory Findings 1. Blood picture and red cell indices. ( i ) Haemoglobin . The essential feature is a fall in haemoglobin concentration. (ii) Red cells. The red cells in the blood film are hypochromic and microcytic , and there is anisocytosis and poikilocytosis . Hypochromia generally precedes microcytosis . (iii) Reticulocyte count. The reticulocyte count is normal or reduced. (iv) Absolute values. The red cell indices reveal a diminished MCV (below 50 ft), MCH (below 15 pg ) and MCHC (below 20 g/dl). (v) Leucocytes. The total and differential white cell counts are usually normal. (vi) Platelets. Platelet count is usually normal.

16. BONE MARROW FINDINGS ( i ) Marrow cellularity . The marrow cellularity is increased due to erythroid hyperplasia (myeloid- erythroid ratio decreased). (ii) Erythropoisis . There is normoblastic erythropoiesis with predominance of small polychromatic normoblasts ( micronormoblasts ). (iii) Other cells. Myeloid, lymphoid and megakaryocytic cells are normal in number and morphology. (iv) Marrow iron. Iron staining (Prussian blue reaction) on bone marrow aspirate smear shows deficient reticuloendothelial iron stores and absence of siderotic iron granules from developing normoblasts

17. BIOCHEMICAL ABNORMALITIES ( i ) The serum iron level is low (normal 80-180 g/dl); it is often under 50 g/dl. (ii) Total iron binding capacity (TIBC) is high (normal 250-450 g/dl) and rises to give less than 10% saturation (normal 33%). (iii) The serum ferritin is very low (normal 150-2000 ng /dl) indicating poor tissue iron stores. (iv) The red cell protoporphyrin is very low.

18. Test Iron Deficiency Chronic Disorders Thalassaemia Sideroblastic Anaemia MCV , MCH, MCHC Reduced Low normal-to-reduced Very low Very low (except MCV raised in acquired type) Serum iron Reduced Reduced Normal Raised TIBC Raised Reduced Normal Normal Serum ferritin Reduced Raised Normal Raised (complete saturation) Marrow-iron stores Absent Present Present Present Iron in normoblasts Absent Absent Present Ring sideroblasts Hb electro- phoresis Normal Normal Abnormal Normal LABORATORY DIAGNOSIS OF HYPOCHROMIC ANEMIAS

19. ANAEMIA OF CHRONIC DISORDERS One of the commonly encountered anaemia is in patients of a variety of chronic systemic diseases in which anaemia develops secondary to disease process but there is no actual involvement of the bone marrow

20. Anaemias Secondary to Chronic Systemic Disorders Chronic Inflammatory Diseases Malignant Diseases Other Disorders TUBERCULOSIS, OSTEOMYELITIS HODGKIN’S DISEASE UREMIA, RENAL FAILURE PYELONEPHRITIS, LUNG ABSCESS DISSEMINATED CARCINOMAS AND SARCOMAS CHRONIC LIVER DISEASE SUBACUTE BACTERIAL ENDOCARDITIS ENDOCRINE FAILURE LIKE MYXOEDEMA COLLAGEN VASCULAR DISEASES LIKE SLE RHEMATOID ARTHRITIS PROTEIN CALORY MALNUTRITION SARCOIDOSIS, CROHN’S DISEASE SCURVY DERMATOMYOCYTIS

21. MEGALOBLASTIC ANEMIA The megaloblastic anaemias are disorders caused by impaired DNA synthesis and are characterized by a distinctive abnormality in the haematopoietic ( erythroid ) precursors in the bone marrow in which the maturation of nucleus is delayed relative to that of the cytoplasm. Mature red cells are also abnormal in shape and size, the most prominent abnormality being macrocytosis . The underlying defect is defective DNA synthesis due to deficiency of vitamin B 12 ( cobalamin ) and/or folic acid ( folate ).

22. Etiologic Classification of Megaloblastic Anaemia   Vitamin B12 Deficiency Folate Deficiency Other Causes Inadequate dietary intake Inadequate dietary intake Impaired metabolism ex. Inhibitors of dihydrofolate (DHF) reductase Malabsorption malabsorption Unknown etiology. Excess urinary folate loss in active liver disease and heart failure

23. CLINICAL FEATURES ANEMIA. GLOSSITIS - SMOOTH RED BEEFY TONGUE NEUROLOGICAL MANIFESTATIONS- PERIPHERAL NEUROPATHY AND SUBACUTE COMBINED DEGENERATION OF THE SPINAL CORD. MILD JAUNDICE, ANGULAR STOMATITIS, PIGMENTATION WEIGHT LOSS AND ANOREXIA.

24. LABORATORY FINDINGS PERIPHERAL SMEAR AND RED CELL INDICES: i . Variable decrease in Hemoglobin levels. ii. Peripheral blood film shows diagnostic macrocytosis of RBCs.Basophilic stipling of RBCs may be seen. iii.Low or normal reticulocyte count. iv.Elevated MCV (above 120 fl) proportionate to the severity of macrocytosis , elevated MCH (above 50 pg) and normal or reduced MCHC. v.Presence of characteristic hypersegmented neutrophils (having more than 5 nuclear lobes) in the blood film should raise the suspicion of megaloblastic anaemia . vi. Moderately reduced platelet count with occasional bizarre cells. vii.Long standing cases may show PANCYTOPENIA.

25. Bone marrow findings: i.Markedly hypercellular due to increased number of megaloblasts . ii.Giant metamyelocytes,Bizarre megakaryocytes with multilobed nuclei may be seen. Biochemical findings: i .↑ serum unconjugated bilirubin and LDH. ii. Normal or ↑serum iron and ferritin . SPECIFIC TESTS FOR THE DIAGNOSIS OF THE CAUSE: i . Serum vitamin B 12 assay ii. Schilling test (Radioisotope absorption test). Schilling test is done to detect vitamin B 12 deficiency as well as to distinguish and detect lack of IF and malabsorption . iii. Tests for Folate Deficiency- the serum and red cell folate assay.

26. HEMOLYTIC ANEMIAS Haemolytic anaemias are defined as anaemias resulting from an increase in the rate of red cell destruction. The red cell life-span is shortened due to accelerated haemolysis . (Normal life-span of RBCs is 120 days). The premature destruction of red cells may occur by 2 mechanisms: 1.Intravascular hemolysis -RBC lyse in the circulation leading to high levels of plasma hemoglobin and sometimes with hemoglobinuria . 2.Extravascular hemolysis - RBC lysis occurs outside the circulation like in RE system.MORE COMMON. Plasma hemoglobin levels may not be raised.

27. CLASSIFICATION ACQUIRED (Extra-Corpuscular) HEREDITARY (Intra-Corpuscular) Antibody: Immunohaemolytic anemias Ex.Auto immune HA, drug induced HA . Abnormalities of red cell membrane 1.Hereditary spherocytosis 2.Hereditary elliptocytosis (hereditary ovalocytosis ) Mechanical trauma: Microangiopathic haemolytic anaemia Disorders of red cell interior Red cell enzyme defects ( i ) G6PD deficiency (ii) pyruvate kinase deficiency 2.Disorders of haemoglobin ( i )Structurally abnormal haemoglobins ( haemoglobinopathies ): sickle syndrome, (ii)Reduced globin chain synthesis: thalassaemias Direct toxic effects: Malaria, bacteria, infection and other agents Acquired red cell membrane abnormalities: paroxysmal nocturnal haemo-globinuria

28. FEATURES OF HEMOLYSIS General clinical features: 1. Pallor of mucous membranes. 2. Positive family history in patients with congenital haemolytic anaemia . 3. Mild fluctuating jaundice. 4. Splenomegaly in most chronic haemolytic anaemias . 5. Pigment gallstones. Laboratory evaluation of haemolysis : Tests of increased red cell break-down. 1. Serum bilirubin – unconjugated (indirect) bilirubin is raised. 2. Urine urobilinogen is raised but there is no bilirubinuria . 3. Faecal stercobilinogen is raised. 4. Serum haptoglobin and haemopexin ( haemoglobin binding proteins) are reduced or absent. 5. Plasma lactic dehydrogenase (LDH) is raised. 6. Evidences of intravascular haemolysis in the form of haemoglobinaemia , haemoglobinuria , methaemoglobinaemia and haemosiderinuria

29. SICKLE CELL ANEMIA This is the most prevalent and typical type of hemoglobinopathy . Sickle hemoglobin( HbS ) forms from a single aminoacid substitution in the globin chain.The valine substitutes glutamic acid at the 6 th position of globin chain. In homozygotes all HbA is replaced by HbS where as in heterozygotes only about half is replaced. It is the most common form of familial hemolytic anemia. It is endemic in central africa where plasmodium falciparum malaria is also endemic.The HbS has small protective role against malaria.

30. PATHOGENESIS At reduced oxygen levels( deoxygenation ) HbS molecules undergo polymerization( also known as CRYSTALLIZATION).These polymers distort the red cell and the cell takes elongated crescentic shape (sickle cell). Sickling of RBCs is reversible initially upon reoxygenation.But repeated attacks damage the membrane and finally cell accumulates calcium,loses potassium and water and becomes irreversibly sickled . The sickling of RBCs is influenced by: 1.Presence of hemoglobins other than HbS . 2.The concentration of HbS in the cell. 3.The length of time RBCs are exposed to low oxygen tension.

31. Major effects of sickling of RBCs The irreversibly sickled cells are dysfunctional and are recognized and removed by phagocytes, resulting in extra vascular hemolysis . The sickling of RBCs through out produces widespread microvascular obstructions resulting in ischemic tissue damage and pain.

32. CLINICAL FEATURES 1. Anaemia with aplastic crisis in between. 2. Vaso -occlusive phenomena. Patients of SS develop recurrent vaso -occlusive episodes throughout their lives due to obstruction of capillaries by sickled cells. Vaso -obstruction affecting different organs and tissues results in infarcts of 2 types: ( i ) Microinfarcts affecting particularly the abdomen, chest, back and joints and are the cause of recurrent painful crises in SS. (ii) Macroinfarcts involving most commonly the spleen, bones, lungs, kidneys, liver and skin, and result in anatomic and functional damage to these organs. 3. Constitutional symptoms. Patients with SS have impaired growth and development and increased susceptibility to infection,formation of gall stones.

33. LAB FINDINGS Moderate to severe anaemia . The blood film shows sickle cells and target cells. A positive sickling test with a reducing substance such as sodium metabisulfite . Haemoglobin electrophoresis shows no normal HbA but shows predominance of HbS and 2-20% HbF .

34. PATHOPHYSIOLOGY AND MORPHOLOGICAL CONSEQUENCES OF SICKLE CELL ANEMIA

35. CLINICAL COURSE UNREMITTING COURSE WITH SUDDEN “CRISES” STAGE. THE MOST SERIOUS OF THESE CRISES ARE: 1.VASO-OCCLUSIVE OR PAIN CRISES. 2.ACUTE CHEST SYNDROME. 3.CENTRAL NERVOUS SYSTEM STROKE. 4.INFECTIONS. ACUTE CHEST SYNDROME AND STROKE ARE THE LEADING CAUSES OF ISCHEMIA RELATED DEATH.

36. THALASSEMIA Diverse group of hereditary disorders in which there is reduced rate of synthesis of one or more of the globin polypeptide chains . Thus, thalassaemias are quantitative abnormalities of globin chain synthesis. Thalassaemias are genetically transmitted disorders Normal adult haemoglobin ( HbA ) is α 2 β 2. Depending upon whether the genetic defect or deletion lies in transmission of α- or ß- globin chain genes, thalassaemias are classified into α- and ß- thalassaemias .

37. Adult Hemoglobin Comprises about:- HbA ( 2 α ,2 β ) 97% HbA2 ( 2 α ,2 δ ) 1.5-3.2% . HbF ( 2 α ,2 ϒ ) < 1%

38. Each of the two main types of thalassaemias may occur as heterozygous (called α- and ß- thalassaemia minor or trait), or as homozygous state (termed α- and ß- thalassaemia major). The former is generally asymptomatic, while the latter leads to severe congenital haemolytic anaemia .

39. Type HB HB-Electrophoresis Clinical Syndrome α - Thalassaemias 1. Hydrops foetalis 3-10 g/dl Hb Barts ( γ 4 ) (100%) Fatal in utero or in early infancy 2. Hb-H disease 2-12 g/dl HbF (10%) Haemolytic anaemia 3. α-Thalassaemia trait 10-14 g/dl Normal Microcytic hypochromic blood picture but no anaemia ß- Thalassaemias 1. ß- Thalassaemia major < 5 g/dl HbA (0-50%) HbF (50-98%) Severe congenital haemolytic anaemia , requires blood transfusions 2. ß- Thalassaemia intermedia 5-10 g/dl Variable Severe anaemia , but regular blood transfusions not required 3. ß- Thalassaemia minor 10-12 g/dl HbA 2 (4-9%) HbF (1-5%) Usually asymptomatic CLASSIFICATION OF THALASSEMIAS

40. β THALASSEMIA Caused by decreased rate of ß-chain synthesis resulting in reduced formation of HbA in the red cells. Most of ß- thalassaemias arise from different types of mutations of ß- globin gene resulting from single base changes.The important ones having effects on ß- globin chain synthesis are: ( i ) Transcription defect; (ii) Translation defect; (iii) mRNA splicing defect. Homozygous form: ß- Thalassaemia major. It is the most severe form of congenital haemolytic anaemia .

41. β THALASSEMIA MAJOR Also termed Mediterranean or Cooley's anaemia is the most common form of congenital haemolytic anaemia . Clinical features: 1. Anaemia starts appearing within the first 4-6 months of life. 2. Marked hepatosplenomegaly . 3. Expansion of bones. 4. Iron overload due to repeated blood transfusions. Laboratory findings: 1. Anaemia . Usually severe. 2. Blood film shows severe microcytic hypochromic red cell morphology, marked anisopoikilocytosis , basophilic stippling, presence of many target cells. 3. Serum bilirubin ( unconjugated ) is generally raised. 4. Reticulocytosis . 5. MCV, MCH and MCHC are significantly reduced. 6. WBC count is often raised. 7. Platelet count is usually normal. 8. Decreased osmotic fragility. 9. Haemoglobin electrophoresis shows presence of increased amounts of HbF , increased amount of HbA 2 , and almost complete absence or presence of variable amounts of HbA . 10. Bone marrow aspirate examination shows normoblastic erythroid hyperplasia

42. THALASSEMIA MINOR THALASSEMIA MAJOR

43. Aplastic Anaemia Aplastic anaemia is defined as pancytopenia (i.e. simultaneous presence of anaemia , leucopenia and thrombocytopenia ) resulting from aplasia of the bone marrow. The underlying defect in all cases appears to be sufficient reduction in the number of haematopoietic pluripotent stem cells which makes them unable to divide and differentiate. Etiology and classification. Based on the etiology, aplastic anaemia is classified into 2 main types: primary and secondary.

44. Causes of Aplastic Anaemia   A. Primary Aplastic Anaemia 1. Fanconi's anaemia (congenital) 2. Immunologically-mediated (acquired)   B. Secondary Aplastic Anaemia 1. Drugs ( i ) Dose-related aplasia e.g. with antimetabolites ( methotrexate ), mitotic inhibitors ( daunorubicin ), alkylating agents ( busulfan ), nitrosourea , anthracyclines . (ii) Idiosyncratic aplasia e.g. with chloramphenicol , sulfa drugs, oxyphenbutazone , phenylbutazone , chlorpromazine, gold salts. 2. Toxic chemicals e.g. benzene derivatives, insecticides, arsenicals. 3. Infections e.g. infectious hepatitis, EB virus infection, AIDS, other vital illness. 4. Miscellaneous e.g. association with SLE and therapeutic X-rays.

45. Clinical features: 1. Anaemia and its symptoms like mild progressive weakness and fatigue. 2. Haemorrhage from various sites due to thrombocytopenia. 3. Infections of the mouth and throat are commonly present. 4. The lymph nodes, liver and spleen are generally not enlarged. Laboratory findings: 1. Haemoglobin levels are moderately reduced. 2. The absolute granulocyte count is particularly low (below 1500/ μl ) with relative lymphocytosis . 3. Platelet count is always reduced. Bone marrow aspirate may yield a 'dry tap'. A trephine biopsy is generally essential for making the diagnosis which reveals patchy cellular areas in a hypocellular or aplastic marrow. Marrow chiefly consists of lymphocytes and plasma cells 

46. WBC DISORDERS

47. LEUKaEMIA The leukaemias are a group of disorders characterized by malignant transformation of blood-forming cells. The proliferation of leukaemic cells takes place primarily in the bone marrow, and in certain forms, in the lymphoid tissues. Ultimately, the abnormal cells appear in the peripheral blood raising the total white cell count to high level. In general, leukaemias are classified on the basis of cell types predominantly involved, into myeloid and lymphoid, and on the basis of natural history of the disease, into acute and chronic . Generally, acute leukaemias have a rapidly downhill course, whereas chronic leukaemias have indolent behaviour . ACUTE LYMPHOID LEUKAEMIA (ALL) is primarily a disease of children and young adults, whereas ACUTE MYELOID LEUKAEMIA (AML) occurs at all ages. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) tends to occur in the elderly. CHRONIC MYELOCYTIC LEUKAEMIA (CML) is found in middle age.

48. ETIOLOGY 1. Genetic factors. There is high concordance rate among identical twins if acute leukaemia develops in the first year of life. Families with excessive incidences of leukaemia have been identified. 2. Environment factors. These include the following: ( i ) Ionizing radiation: Radiation exposure is related to the development of CML, AML and ALL but not to CLL or HCL. (ii) Chemical carcinogens: Benzene and other aromatic hydrocarbons. (iii) Certain drugs: Treatment with alkylating agents and other chemotherapeutic agents. 3. Infection: adult T-cell leukaemia -lymphoma (ATLL ) by a human retrovirus called human T-cell leukaemia -lymphoma virus I ( HTLV-I ) and HTLV II for T cell variant of hairy cell leukaemia is well established.

49. PATHOGENESIS Arises following malignant transformation of a single clone of myeloid or lymphoid series , followed by proliferation of the transformed clone. The most prominent characteristic of the leukaemic cells is a defect in maturation beyond the myeloblast or promyelocyte level in AML, and the lymphoblast level in ALL. It is the maturation defect in leukaemic blasts rather than rapid proliferation responsible for causing acute leukaemia .

50. The leukaemic cells proliferate primarily in the bone marrow, circulate in the blood and infiltrate in to other tissues such as lymph nodes, liver, spleen, skin, viscera and the central nervous system. The mechanism of leukaemic transformation is poorly understood. But, The most consistent chromosomal abnormality among these is Philadelphia (Ph) chromosome seen in 70-90% cases with CML , involving reciprocal translocation of parts of long arm of chromosome 22 to the long arm of chromosome 9. t(9;22). As the leukaemic cells accumulate in the bone marrow, they suppress normal haematopoietic stem cells.

51. ACUTE LEUKAEMIAS Acute leukaemias are characterized by predominance of undifferentiated leucocyte precursors or leukaemic blasts . ACUTE MYELOGENOUS LEUKAEMIA (AML) Primarily affects older adults with median age being 50 yrs Clinical signs and symptoms are related to marrow failure caused by the replacement of normal marrow elements by leukemic blasts. Fatigue and pallor, abnormal bleeding and infections are common presenting features. Splenomegaly and lymphadenopathy are less prominent compared with ALL.

52. PATHOPHYSIOLOGY Association with acquired mutations in transcription factors which inhibit normal myeloid differentiation is seen. Ex. T(15;17)translocation in acut promyelocytic leukemia Morphology: Myeloblasts or promyelocytes make up more than 20% of the bone marrow cellularity . - Myeloblasts have delicate nuclear chromatin,3-5 nucleoli and fine azurophilic granules in the cytoplasm. -Distinctive red staining rodlike structures ( auer rods) are present in myeloblasts or in promyelocytes . -These auer rods are found only in neoplastic myeloblasts and are thus helpful as diagnostic clue when present. - Monoblasts , erythroblasts or megakaryoblasts predominate in other types of AML

53. REVISED FAB CLASSIFICATION OF AML CLASS DEFINITION INCIDENCE(%) MORPHOLOGY CYTOCHEMISTRY M 0 MINIMALLY DIFFERENTIATED AML 2-3 BLASTS LACK AUER RODS.EXPRESS MYELOID LINEAGE SURFACE MARKERS MEYLOPEROXIDASE NEGATIVE. M 1 AML WITHOUT MATURATION 20 VERY LITTLE MATURATION BEYOND MYELOBLAST STAGE MYELOPEROXIDASE + M 2 AML WITH MATURATION 30-40 >20% OF MARROW CELLS ARE MYELOBLASTS.AUER RODS +.OFTEN ASSOCIATED WITH t(8:21) MYELOPEROXIDASE +++ M 3 ACUTE PROMYELOCYTIC LEUKEMIA 5-10 MOSTLY ABNORMAL PROMYELOCYTES. AUER RODS+.YOUNGER PATIENTS. STRONG ASSOCIATION WITH t(15;17).HIGH INCIDENCE OF DIC. MYELOPEROXIDASE +++ M 4 ACUTE MYELOMONO CYTIC LEUKEMIA 15-20 MYELOCYTIC AND MONOCYTIC DIFFERENTIATION. AUER RODS +/- MYELOPEROXIDASE +++ NONSPECIFIC ESTERASE +

54. CLASS DEFINITION INCIDENCE(%) MORPHOLOGY CYTOCHEMISTRY M 5 ACUTE MONOCYTIC LEUKEMIA 10 MONOBLASTS AND IMMATURE MONOCYTIC CELLS. AUER RODS-.OLDER PATIENTS. ORGANO MEGALY+ LYMPHADENOPATHY+ NON SPECIFIC ESTERASE + M 6 ACUTE ERYTHRO LEUKEMIA 5 ABUNDANT DYSPLASTIC ERYTHROID PROGENITORS. >20% ARE MYELOBLASTS. AUER RODS+ OLD AGE. MYELOPEROXIDASE+ PAS+ (ERYTHROID SERIES) M 7 ACUTE MEGAKARYOBLASTIC LEUKEMIA 1 MEGAKARYOBLASTS+++ MYELOFIBROSIS+ INCREASED RETICULIN. AUER RODS - PLATELET PEROXIDASE +

55. FAB CLASSIFICATION OF ACUTE LYMPHOBLASTIC LEUKEMIA CLASS DEFINITION INCIDENCE MORPHOLOGY CYTOCHEMISTRY L 1 CHILDHOOD ALL B-ALL AND T-ALL MORE COMMON IN CHILDREN UNIFORM SMALL LYMPHOBLASTS, SCANTY CYTOPLASM, ROUND NUCLEUS AND INCONSPICUOUS NUCLEOLI PAS +/- ACID PHOSPHATASE +/- L 2 ADULT ALL MOSTLY T-ALL MORE COMMON IN ADULTS HETEROGENOUS LYMPHOBLASTS, VARIABLE CYTOPLAM,LARGE NUCLEOLI,IRREGULAR CLEFTED NUCLEI PAS +/- ACID PHOSPHATASE +/- L 3 BURKITT TYPE ALL (B-ALL) UNCOMMON LARGE HOMOGENOUS LYMPHOBLASTS, ROUND NUCLEI, PROMINENT NUCLEOLI,CYTOPLASMIC VACUOLATION PAS – ACID PHOSPHATASE --

56. ACUTE MYELOID LEUKEMIA ARROW SHOWS ÁUER ROD’.

57. AML- BONE MARROW

58. ACUTE LYMPHOBLASTIC LEUKEMIA FLOW CYTOMETRY

59. ACUTE LYMPHOID LEUKEMIA

60. CHRONIC MYELOGENOUS LEUKAEMIA(CML) Chronic myeloid ( myelogenous , granulocytic) leukaemia comprises about 20% of all leukaemias and its peak incidence is seen in 3 rd and 4 th decades of life. A distinctive variant of CML seen in children under 3 years of age is called juvenile CML. Clinical Features Features of anaemia such as weakness, pallor, dyspnoea and tachycardia. Symptoms due to hypermetabolism such as weight loss, anorexia, night sweats. Splenomegaly is almost always present and is frequently massive. Bleeding tendencies in blast crises. Juvenile CML is more often associated with lymph node enlargement than splenomegaly .

61. Laboratory Findings Blood picture: 1.Anaemia. It is of moderate degree, normocytic normochromic . 2.White blood cells. Characteristically, there is marked leucocytosis (approximately) 200,000/ μl or more at the time of presentation). The natural history of CML consists of 2 phases – chronic and blastic . The chronic phase of CML begins as a myeloproliferative disorder and consists of excessive proliferation of myeloid cells of intermediate grade (i.e. myelocytes and metamyelocytes ) and mature segmented neutrophils . Myeloblasts usually do not exceed 10% of cells in the peripheral blood and bone marrow. An increase in basophils up to 10% is a characteristic feature. A rising basophilia is indicative of impending blastic transformation. An accelerated phase of CML is also described in which there is progressively rising leucocytosis associated with thrombocytosis or thrombocytopenia and splenomegaly . The blastic phase or blast crisis in CML may be myeloid or lymphoid in origin. Myeloid blast crisis in CML is more common and resembles AML. 3.Platelets. The platelet count is raised in about half the cases.

62. ii.Bone marrow examination: 1.Cellularity. There is hypercellularity with total or partial replacement of fat spaces by proliferating myeloid cells. 2.Myeloid cells. The myeloid cells predominate with increased myeloiderythroid ratio. The differential counts of myeloid cells show similar findings as seen in the peripheral blood with predominance of myelocytes . 3.Erythropoiesis. Erythropoiesis is normoblastic but there is reduction in erythropoietic cells. 4.Megakaryocytes. These are conspicuous but are usually smaller in size. 5.Cytogenetics. Cytogenetic studies on blood and bone marrow cells show Philadelphia (Ph) chromosome. iii.Cytochemistry : The only significant finding on cytochemical stains is reduced scores of neutrophil alkaline phosphatase (NAP) which helps to distinguish CML from myeloid leukaemoid reaction in which case NAP scores are elevated. THE MOST COMMON CAUSE OF DEATH (80% CASES) IS BLASTIC TRANSFORMATION

63. CHRONIC MYELOID LEUKEMIA

64. PHILADELPHIA CHROMOSOME

65. CHRONIC LYMPHOCYTIC LEUKEMIA(CLL) Chronic lymphocytic leukaemia constitutes about 25% of all leukaemias and is predominantly a disease of the elderly (over 60 years of age) with a male preponderance (male-female ratio 2:1). Clinical Features 1. Features of anaemia such as weakness, fatigue and dysponea . 2. Enlargement of superficial lymph nodes. 3. Splenomegaly and hepatomegaly are usual. 4. Haemorrhagic manifestations are found in CLL with thrombocytopenia. 5. Infections, particularly of respiratory tract, are common. Laboratory Findings i . Blood picture: 1. Anaemia . Anaemia is mild to moderate and normocytic normochromic type. 2. White blood cells. Typically, there is marked leucocytosis (50,000-200,000/ μl ). Usually, more than 90% of leucocytes are mature small lymphocytes. Smear cells (degenerated forms) are present. 3. Platelets. The platelet count is normal or moderately reduced.

66. ii. Bone marrow examination: 1. Increased lymphocyte count (25-95%). 2. Reduced myeloid precursors. 3. Reduced erythroid precursors. iii. Other investigations: 1. Serum immunoglobulin levels are generally reduced. 2. Coombs' test is positive in 20% cases.

67. Prognosis is better than CML since blastic transformation of CLL seldom occurs. Prognosis correlates with the stage of disease under: Stage A : lymphocytosis alone, or with limited lymphadenopathy , has a good prognosis (median survival more than 10 years). Stage B : lymphocytosis with significant lymphadenopathy and hepatosplenomegaly has intermediate prognosis (median survival about 5 years). Stage C : lymphocytosis with associated anaemia and thrombocytopenia has a worse prognosis (median survival of less than 2 years).

68. Coagulation Disorders von Willebrand's Disease ( vWD ) is the most common hereditary coagulation disorder occurring due to qualitative or quantitative defect in von Willebrand's factor ( vWF ). The gene for vWF is located at chromosome 12. Classic Haemophilia ( Haemophilia A) It is the second most common hereditary coagulation disorder next to von Willebrand's disease, occurring due to deficiency or reduced activity of factor VIII (anti- haemophilic factor). The disorder is inherited as a sex-(X)-linked recessive trait and, therefore, manifests clinically in males, while females are usually the carriers.

69. Disseminated intravascular coagulation (DIC) Disseminated intravascular coagulation ( DIC) , is a complex thrombo-haemorrhagic disorder occurring as a secondary complication in some systemic diseases.It is caused by the systemic activation of the coagulation pathways ,leading to the formation of thrombi throughout the microcirculation. As a consequence of the widespread thromboses, there is consumption of platelets and coagulation factors. Etiology. Most frequent causes are as under: 1.Massive tissue injury : in obstetrical syndromes (e.g. abruptio placenta, amniotic fluid embolism, retained dead foetus ), massive trauma, metastatic malignancies, surgery. 2. Infections : especially endotoxaemia , gram-negative and meningococcal septicaemia , certain viral infections, malaria, aspergillosis . 3.Widespread endothelial damage : in aortic aneurysm, haemolytic-uraemic syndrome, severe burns, acute glomerulonephritis . 4. Miscellaneous : snake bite, shock, acute intra-vascular haemolysis , heat stroke.

70. DISEASES OF LYMPHOID ORGANS

71. LYMPHNODE Two main functions of the lymph node are:- mount immune response Active phagocytosis for particulate material. Lymph nodes are secondarily involved in a variety of systemic diseases, local injuries and infections, and are also the site for some important primary neoplasms .

72. REACTIVE LYMPHADENTITIS Acute Nonspecific Lymphadenitis : Acutely inflamed nodes are enlarged, tender, and if extensively involved, may be fluctuant. Chronic Nonspecific Lymphadenitis: 3 PATTERNS ARE SEEN -Follicular hyperplasia - Paracortical lymphoid hyperplasia -Sinus histiocytosis or sinus hyperplasia

73. Here is the normal appearance of a benign reactive lymph node. At the top is the capsule and just under that a subcapsular sinus where lymphatics enter that drain tissues peripheral to the node. Beneath the capsule is the paracortical zone with lymphoid follicles having a pale germinal center in which the immune responses are often generated. Beneath this are sinusoids extending to the center of the node.

74. MALIGNANT LYMPHOMAS Lymphomas are malignant tumours of lymphoreticular origin. Two distinct clinicopathologic groups are routinely distinguished: I. Hodgkin’s lymphoma or Hodgkin’s disease (HD) characterized by pathognomonic presence of Reed-Sternberg cells . This group comprises about 25% of all cases of malignant lymphoma. II. Non-Hodgkin’s lymphomas (NHL ) are more common and comprise the rest of cases(75%).

75. HODGKIN’S LYMPHOMA Hodgkin’s disease (HD) primarily arises within the lymph nodes and involves the extranodal sites secondarily. The incidence of the disease has bimodal peaks – one in young adults between the age of 15 and 35 years and the other after 5 th decade of life . THE CLASSICAL DIAGNOSTIC FEATURE IS THE PRESENCE OF REED-STERNBERG (RS) CELL.

76. Etiopathogenesis Unlike most other malignancies, the number of neoplastic cells (i.e. R-S cells ) is very small (less than 5%) which are interspersed in the predominant reactive cells. presently, there is general consensus on monoclonal lymphoid cell origin of R-S cell from B-cells in most subtypes of Hodgkin’s disease. RS cells in all types of Hodgkin’s disease, except in lymphocyte predominance type, express immunoreactivity for CD 15 and CD30. The following possible hypotheses for etiology are suggested: 1. Infectious etiology , possibly infection with an oncogenic virus such as Epstein-Barr virus , human T lymphotropic viruses ( HTLV-I and HTLV-II), HIV and herpesvirus-6. 2.Genetic etiology is suggested by others on the basis of observation of occurrence of HD in families and with certain HLA type. HD is 99 times more common in identical twin of an affected case. 3.Presence of reactive inflammatory cells in the HD is due to secretion of cytokines (e.g . interleukin-5) from the RS cells.

77. Classification of Hodgkin Lymphoma (WHO) Nodular lymphocyte predominant Classical HL Nodular sclerosis Lymphocyte-rich Mixed cellularity Lymphocyte depleted

78. LYMPHOCYTIC PREDOMINANCE TYPE (NODULAR AND DIFFUSE FORMS) Incidence : 5% Histology shows mainly proliferating lymphocytes and histiocytes . Rs cells: malignant cells termed the L &h cell or “popcorn cell ”. Large cell with a lobulated and folded nucleus. Prominent nucleolus, often basophilic. Immunophenotyping : CD15 – ve , CD 30 – ve and CD20 + ve . EBV – ve . Prognosis : excellent

79. NODULAR SCLEROSIS TYPE Incidence: 70% Histology shows lymphoid nodules and collagen bands Rs cells: frequent, lacunar type. Immunophenotyping : CD15+ve , CD 30 + ve . EBV – ve . Prognosis: very good.

80. MIXED CELLULARITY Incidence: 22% Mixed infiltrate of lymphocytes,plasma cells eosinophils and monocytes . Rs cells: numerous, classic type. Immunophenotyping : CD15 + ve , CD 30 +ve . EBV + ve (70%). Prognosis: good

81. LYMPHOCYTE DEPLETION (FIBROTIC AND RETICULAR VARIANTS) Incidence : 1% Scanty lymphocytes, atypical histiocytes and fibrosis. Rs cells: numerous, Pleomorphic type Immunophenotype : CD15+ve and CD 30+ve EBV + ve . Prognosis : poor

82. LYMPHOCYTE RICH Incidence: < 5% Sheets of lymphocytes With scanty stroma Rs cells: moderate classic type Immunophenotype : CD15 + ve , CD30 + ve EBV + ve ( 40%) Prognosis: good

83. REED – STERNBERG CELL

84. CLINICAL FEATURES All subtypes , except the nodular sclerosis variety, are more common in males. 1. Patients present with painless, movable and firm lymphadenopathy . 2. Approximately half the patients develop splenomegaly during the course of the disease. Liver enlargement too may occur. 3. Constitutional symptoms (type B symptoms) are present in 25-40% of patients. The most common is low-grade fever with night sweats and weight loss. Other symptoms include fatigue, malaise, weakness and pruritus .

85. Staging Following biopsy and histopathologic classification of HD, the extent of involvement of the disease (i.e. staging) is studied to select the proper treatment and assess the prognosis. The Ann Arbor staging classification takes into account both clinical and pathologic stage of the disease. The suffix A or B are added to the above stages depending upon whether the three constitutional symptoms (fever, night sweats and unexplained weight loss exceeding 10% of normal) are absent (A) or present (B). the suffix E or S are used for extranodal involvement and splenomegaly respectively

86. State I (A or B) I I E Involvement of a single lymph node region. Involvement of a single extra-lymphatic organ or site. Stage II (A or B) II Involvement of two or more lymph node regions on the same side of the diaphragm. II E (or) with localized contiguous involvement of an extra-nodal organ or site. Stage III (A or B) III Involvement of lymph node regions on both sides of the diaphragm. III E (or) with localized contiguous involvement of an extra-nodal organ or site. III S (or) with involvement of spleen. III ES (or) both features of III E and III S Stage IV (A or B) IV Multiple or disseminated involvement of one or more extra-lymphatic organs or tissues with or without lymphatic involvement. Ann Arbor Staging Classification of Hodgkin’s Disease

87. NON HODGKIN’S LYMPHOMAS (NHL) Non-Hodgkin’s lymphomas ( NHL ) are the malignant neoplasms of the Cells of the immune system and are more common than Hodgkin’s lymphoma. Majority of NHL arise in lymph nodes (65%) while the remaining 35% take origin in extranodal lymphoid tissues . However, all forms of NHL have potential to spread to other lymph nodes, liver, spleen and bone marrow.

88. IMPORTANT POINTS TO REMEMBER REGARDING LYMPHOID NEOPLASMS B and T cell tumors are often composed of cells which are derived from specific stages of their normal differentiation pathways. Most of the lymphomas in the adults are derived from follicular centre or post follicular centre B cells. All lymphoid tumors are derived from a single transformed cell and are therefore monoclonal. These tumors disrupt normal immune regulatory mechanisms- both immunodeficiency and autoimmunity conditions can be seen with these tumors. Most of these tumors are widely disseminated at the time of diagnosis. So only systemic therapies are curative in these tumors.

89. CLASSIFICATION OF NHL Rappaport Classification (1966) Lukes -Collins Classification (1974) Working Formulations for Clinical Usage (1982) R.E.A.L Classification (1994)

90. WHO CLASSIFICATION OF LYMPHOID NEOPLASMS -1999. PRECURSOR B CELL NEOPLASMS - PRECURSOR B-CELL LEUKEMIA/LYMPHOMA( B CELL ALL) PERIPHERAL B CELL NEOPLASMS - B CELL CHRONIC LYMPHOCYTIC LEUKEMIA/SMALL LYMPHOCYTIC LYMPHOMA( CLL/SLL) -B CELL PROLYMPHOCYTIC LEUKEMIA -LYMPHOPLASMACYTIC LYMPHOMA -MANTLE CELL LYMPHOMA -FOLLICULAR LYMPHOMA -MALT LYMPHOMA -SPLENIC MARGINAL ZONE LYMPHOMA -NODAL MARGINAL ZONE LYMPHOMA -HAIRY CELL LEUKEMIA -PLASMACYTOMA/PLASMACELL MYELOMA -DIFFUSE LARGE B CELL LYMPHOMA -BURKITT’S LYMPHOMA

91. PRECURSOR T CELL NEOPLASMS - PRECURSOR T CELL LEUKEMIA/LYMPHOMA(T CELL ALL) PERIPHERAL T/NK CELL NEOPLASMS -T CELL PROLYMPHOCYTIC LEUKEMIA -T CELL GRANULAR LYMPHOCYTIC LEUKEMIA -MYCOSIS FUNGOIDES/SEZARY SYNDROME -PERIPHERAL T CELL LYMPHOMA –NOS -ANGIOIMMUNOBLASTIC T CELL LYMPHOMA -ANAPLASTIC LARGE CELL LYMPHOMA -ENTEROPATHY TYPE T CELL LYMPHOMA -PANNICULITIS LIKE T CELL LYMPHOMA -HEPATOSPLENIC γδ CELL LYMPHOMA -ADULT T CELL LYMPHOMA/LEUKEMIA(HTLV-1) -NK/T CELL LYMPHOMA NASAL TYPE -NK CELL LEUKEMIA

92. FOLLICULAR LYMPHOMA Common tumor forming 40% of adult NHL. Lymph node replaced by nodular proliferations of tumor cells. Tumor cells resemble normal follicular centre B cells,mostly centrocyte like cell. Tumors express markers- CD19 and CD20, CD10 and BCL -6 and BCL -2 . (Not seen in normal follicular cells) Majority show t(14;18) translocation. Occurs in older persons and equally in males and females. Painless lymphadenopathy and bone marrow involvement are characteristic. Not easily curable

93. DIFFUSE LARGE B CELL LYMPHOMA Most important type of lymphoma in adults and accounts for 50% of lymphomas. It has diffuse growth pattern and aggressive clinical behavior Tumor cells are 3-4 times larger than the normal lymphocytes. Express markers like CD19 and CD 20. many express surface Igm or IgG . 30% of tumors show t(14;18) translocation. Mutations of BCL -6 are also seen. Though mostly seen in old age they can also be seen in children and young patients. Extranodal presentation is common. Involvement of bonemarrow , liver or spleen are not common. These are aggressive tumors and fatal if not treated properly

94. BURKITT’S LYMPHOMA Endemic in parts of africa and sporadic in other parts of the world. Both endemic and nonendemic forms affect mainly children and young adults. In both forms the disease arises in extranodal sites. In african patients involvement of maxilla or mandible is common and in sporadic cases bowel, retroperitoneum and ovaries are commonly affected Tumor cells are uniform in size and gives ‘STARRY –SKY ‘ pattern histologically . High mitosis++ Express surface IgM and markers CD19 and CD20 and CD10 Always shows t(8;14) translocation and some may show t(2;22) translocation also. High grade fastest growing tumor but can be cured with aggressive chemotherapy.

95. LYMPHNODE SWELLING – APPROACH FOR A DIAGNOSIS

96. SPLENOMEGALY Causes: I. Infections: tuberculosis , typhoid, brucellosis, infectious mononucleosis , malaria, kalaazar , schistosomiasis . II. Congestive states related to portal hypertension: cirrhosis of the liver , portal vein thrombosis , cardiac failure. III. Lymphohematogenous disorders: lymphomas , leukemias , hemolytic anemias , myeloproliferative disorders. IV. Inflammatory-immunologic conditions: rhematoid arthritis, SLE. V. Storage disorders: gaucher’s disease, niemann -pick’s disease, mucopolysaccharidoses . VI. Miscellaneous: amyloidosis . VII. Tumors: primary and metastatic.