Cystic diseases of bone

CYSTIC DISEASE OF BONE

1. APPROACH TO CYSTIC LESIONS OF BONE PRESENTER:DR.ARGHA BARUAH MODERATOR:DR.TN SURESH DR.SIDDARAM.N PATIL

2. Outline 1.Definition 2.Classification 3.Approach to cystic lesions 4.Cystic lesions(individually) 5.Cases 6.Summary

3. Case1 : 20 year female presented with progressive pain in the clavicular region since 4 months Anastomosing trabeculae of osteoid.Rimmed by single layer of benign activated osteoblasts.Numerous osteoclasts

4. CASE 2: 20 YEAR F PRESENTED WITH PAIN AND SWELLING IN THE KNEE JOINT SINCE 2 MONTHS. well-defined, expansile osteolytic lesion with thin peripheral bone shell

5. What is a cystic lesion of bone? Cysts are closed capsule or sac-like structures, typically filled with liquid, semisolid or gaseous material . Cysts lesions of bone develop when one or several factors that affect bone remodelling cause a focally increased rate of resorption relative to the formation

6. Numerous influences may produce this net effect: 1) tumor 2)vascular disturbances(ABC) 3) intraosseous enzymatic effect(Unicameral bone cyst) 4)hormonal influences such as parathormone linked osteoclastic resorption 4)external factors-trauma, infection (osteomyelitis),inflammation(rheumatoid arthritis),degenerative joint disease

7. Benign cystic lesions classification:

8. Malignant cystic lesions of bone: Giant cell tumor Osteosarcoma Chondrosarcoma Multiple myeloma Ewings sarcoma Metastasis- lung,renal ,thyroid

9. Osteolytic lesion of bone:

10. A L T - M C P S A ge L ocation T ransitional zone M atrix C ortex P eriosteal reaction S oft tissue swelling

11. According to the age:

12. According to location: Epiphysis: In young patients it is likely to be either a chondroblastoma or an infection. In patients over 20, a giant cell tumor has to be included in the differential diagnosis. In older patients a geode, i.e. degenerative subchondral bone cyst must be added to the differential diagnosis. Metaphysis: NOF, SBC, Osteosarcoma, Chondrosarcoma , Enchondroma and infections. Diaphysis: Ewing's sarcoma, SBC, ABC, Enchondroma , Fibrous dysplasia

13. Location: Centric in long bone: SBC, eosinophilic granuloma, fibrous dysplasia, ABC and enchondroma are lesions that are located centrally within long bones. Eccentric in long bone: Osteosarcoma, NOF, chondroblastoma ,, GCT and osteoblastoma are located eccentrically in long bones.

14. Zone of transition: In order to classify osteolytic lesions as well-defined or ill-defined, we need to look at the zone of transition between the lesion and the adjacent normal bone. Wide zone of transition: An ill-defined border with a broad zone of transition is a sign of aggressive growth Small zone of transition: A small zone of transition results in a sharp, well-defined border and is a sign of slow growth.

15. Matrix Ground Glass – Fib.Dys . Calcification - Chondrosarcoma

16. Matrix “Cloud” like Ossific densities in Bone = Osteosarcoma

17. Wide Zone of Transition and Broken Cortex could be signs of Aggressiveness / Malignancy Cortex: Intact or Broken

18. Soft Tissue Enormous soft tissue seen in Ewing’s Sarcoma

19. According to symptoms(if no pain): Fibrous Dysplasia Enchondroma NOF Solitary Bone Cyst

20. Multiple Lesions???? Mnemonic: FEEMHI Fibrous dysplasia EG Enchondroma Mets, Myeloma Hyperparathyroidism Infection

21. ANEURYSMAL BONE CYST Solitary expansile Blood filled reactive lesion of bone . Locally destructive. Age : - usually in 1 st ,2 nd & 3 rd decade of life . Sex : - slight female predominance. Location :- any bone may be involved. -Most common is proximal humerus ,distal femur,proximal tibia & spine. Types :- Primary : apears de novo following intraosseous A-V fistula. Secondary : - results of cystic changes in GCT ,OSTEOBLASTOMA etc.

22. ANEURYSMAL BONE CYST Clinical feature :- -Pt complain of mild to moderate pain. Swelling Limitation of joint movements. - Neurological deficit or radicular pain . -Rapid growth may occur which clinically presents as a malignancy. X ray findings :- Affected bone is expanded, cystic & ballooned outward. Eccentrically placed. Cortex is breached . Surrounded by a faint outline representing new periosteal bone.

23. ANEURYSMAL BONE CYST Other investigation:- Bone scan :- shows diffuse or peripheral tracer uptake with decreased uptake in center. Ct scan :- helpful in delineating the cyst in complex area ex. Spine ,pelvis . MRI :- shows multi loculated cavities & fluid level.

24. ANEURYSMAL BONE CYST PATHOLOGY :- GROSS :- Large mass is attached by a broad base to the shaft of long bone . Growing outwards & displacing the soft tissue. Thin shell of bone enclosing the blood filled spaces. Spongy honeycombed blood filled mass with cystic spaces Microscopic :- Bone & marrow are replaced by the large pool of blood enclosed in fibro osseous septae . Connective tissue bordering the vascular space contain multinucleated giant cells, new bone formation & calcium deposits .

25. Treatment :- Curettage & bone grafting. Marginal resection Is indicated in expendable bone Low dose radiation has been used effectively ,associated with rapid ossification.

26. SOLITARY BONE CYST Is a common lesion Age :- most commonly in 5-15 yrs rarely after 20 yrs Sex :- male predominant (2:1) Location :- long tubular bones particularly humerus & femur - metaphyseal region is the preferred site. 2 types :- Active cystic lesion :- develops under 10yrs age . Within 1cm of epiphysis Benign latent cyst :- develops after 20 yrs age. Towards diaphysis - seperated from epiphysis

27. S OLITARY BONE CYST Physical findings :- - Usually asymptomatic. Cyst lying adjacent to growth plate can lead to growth disturbances. X ray findings :- centrally located ,lytic lesion. Expansion of the bone. Well marginated outline. Thinning of the cortex( scalloping). - Fallen fragment sign -- loculated appearance is due to presence of ridges over inner surface of cyst.

28. SOLITARY BONE CYST Pathology :- Gross :- - Bone displays an area of fusiform expansion. - Underlying bone is egg-shell thin. - Cavity contain yellow fluid . - Microscopic : - - Connective tissue composed of fibroblast contaning multinucleated giant cells , foam cell. - Cortical wall consist of loosely trabeculated osseous tissue & many thin walled vessels.

29. Unicameral bone cyst is filled with straw colored fluid rich in prostaglandins, GAGs, mucopolysaccharides and lysosomal enzymes. This fluid contributes to bone resorption .

30. SOLITARY BONE CYST Treatment : - Curettage Aspiration Steroid injection

31. FIBROUS DYSPLASIA Non inherited , sporadic developmental anomaly. Replacement of bony tissue with fibrous tissue. Age :- begins in childhood(<10 yrs ). Sex :- M:F=1:1 Location :- base of the skull & long bones. Clinical features:- -Pain -Limp -Deformity -Asymmetry of face -Endocrine disorder -Limb length discrepancy. -Sexual precocity

32. It can be Monostotic form (85%) Polyostotic form (15%) Craniofacial form- Leontiasis Ossea Cherubism McCune McCune-Albright Syndrome (10%) Polyostotic , café-au au- lait , endocrine dysfunction (precocious female puberty (20%), hyperthyroidism) MAZABRAUD’s syndrome: ( polyostotic F.D + intramus . Myxomas )

33. RIBS>FEMUR>TIBIA>MAXILLA>MANDIBLE>SKULL>HUMREUS . INTRAMEDULLARY ,ECENTRIC OR CENTRAL LOCATION.

34. FIBROUS DYSPLASIA Radiological findings : - - intramedullary & predominantly diaphyseal . -central or eccentric in location. -Ground glass appearance. -lesion is well defined with sclerotic margins -Cortex thinning & expansion is seen. -Pathological fractures . -Bowing of bones. -HARRISON’S GROOVE.

35. FIBROUS DYSPLASIA Pathology :- Gross :- -Bone is irregular in shape & bent. -Grey tough fibrous tissue that cut with a gritty resistance “SANDPAPER” -Well circumscribed, -Tan-white-yellow, gritty -Cortical bone often thin and expanded Micro :- - composed of dense,mature collagenous tissue. -fibroblast are oriented in linear /whorl pattern. -Curvilinear trabeculae (Chinese letters) of metaplastic woven bone in hypocellular , fibroblastic stroma

36. TREATMENT - Conservative management includes bracing & modification of activities. Surgical management :- -Pathological fracture usually heals but develops deformity. -Fracture of long bone should be treated preferably with I.M nails along with bone grafts. Large lesion which jeopardize the integrity of bone should be treated with curettage & bone grafting

37. Arthritis related cyst: Subchondral cyst: multiple,vary in size,occur in one or both sides of joint,central location,more in weight bearing bones. Pyriform in shape and multilocular . Contiguous with the joint or may have fine bone plate.End of the bone shows degenerative changes

38. INTRAOSSEOUS GANGLION CYST Lesion of uncertain pathogenesis. Age :- can occur at any age. Most commonly seen in 20-60yrs age . Location :- subchondral region of bone , acetabulum & carpel bones. Clinical feature :-are usually clinically silent. -Chronic mild pain -Swelling if associated with soft tissue ganglion. -Usually solitary

39. INTRAOSSEOUS GANGLION CYST Radiographic findings :- -Well demarcated ,sharply circumscribed osteolytic lesion. -Sclerotic margin is evident. -In para articular location gas may be evident. Treatment :- - Local excision of overlying soft tissue & curettage of involved bone. - Recurrence is rare.

40. EPIDERMOID CYST Uncommon. M >F Age :- usually in 2nd ,3rd & 4th decade of life. Location :- skull & phalanges of hand are commonly affected. Clinically :- Pain & swelling Microscopically :- They resemble epidermal cyst of skin. Cysts are filled with keratinous material & lined by squamous epithelium.

41. EPIDERMOID CYST RADIOGRAPHIC :- Well defined osteolytic lesion with sclerotic margins . CT & MRI are rarely required. Treatment :- Excision

42. Giant cell reparative granuloma:

43. CHONDROMA Benign lesions of hyaline cartilage . It can arise within a bone ( ENCHONDROMA ) or on the surface of bone ( PERIOSTEAL /JUXTACORTICAL CHONDROMA).

44. ENCHONDROMA Age :- usually all age group are affected . More commonly young individual in 2 nd -4 th decade . Sex : - equally (M:F=1:1) Location :- any bone can be affected but commonly phalanges of hand & feet. -solitary enchondromas involve humerus , tibia & femur. Clinical findings :- - Swelling -Tenderness -Pain

45. ENCHONDROMA X RAYS FINDINGS :- -well-defined lytic lesion in the hand is almost always an enchondroma -small loculated area with well defined margins. -Cortex is thinned & expanded. - Interlesional calcification :- calcification is irregular Stippled ,punctate or popcorn. -no reactive bone formation CT scan :- Evaluate endosteal erosion to rule out chondrosarcoma .

46. ENCHONDROMA Pathology :- Gross :- - Tumour is surrounded by a fibrous capsule . -The neoplastic tissue is composed of bluish white translucent cartilage - Areas of calcification . Microscopically :- - Tumour shows stages of cartilage formation. -Mesenchymal tissue is seen at periphery. - Most mature cartilage is seen at center.

47. Ollier’s Disease= multiple enchondromas which usually develop in childhood. The growth of these enchondromas usually stops after skeletal maturation.The affected extremity is shortened (asymmetric dwarfism) and sometimes bowed due to epiphyseal fusion anomalies. Persons with Ollier disease are prone to breaking bones and normally have swollen, aching limbs. Maffucci’s Syndrome =characterized by enchondromas and soft tissue hemangiomas

48. TREATMENT Treatment of solitary enchondroma consist of observation with serial radiographs. If the lesion appears to be radiographically stable & asymptomatic then no further investigation is required. If the lesion appears to be unstable , growing then extended curettage is done.

49. CHONDROMYXOID FIBROMA Least common cartilage tumour . Not known to metastasize . 2% of all benign tumour . Seen in patients <30yrs specially in 2 nd & 3 rd decade - Tumour is more common in male (M:F=2:1). -Observed in long tubular bones specially in lower extremity .

50. CHONDROMYXOID FIBROMA Clinical features :- Pain near the joint without h/o trauma Occasionally swelling Pathological fractures ( rare) May presents with soft tissue swelling. Radiographic findings :- -Translucent mass located eccentrically. Fusiform expansion in small bones. Cortex is expanded & thinned. Margin’s are scalloped & sclerosis +. Periosteal reaction is uncommon.

51. CHONDROMYXOID FIBROMA Pathology :- Gross : - -Cut surface reveals solid tumour mass containing small cavities with mucoid tissue. -Calcified areas are unusual. -Surface is sharply demarcated ,lobulated & surrounded by thin scalloped border of dense bone. Microscopic :- Composed of lobulated areas of stellate cells with indistinct cytoplasmic borders. At the periphery ,the appearance is more cellular & collagenous.

52. TREATMENT -local excision & filling the cavity with autogenous bone. -Curettage is not sufficient as tumour may recure especially childrens. -Wide en- bloc excision gives high rate of cure. -If tumour recure even after en bloc excision then studies has to be done to rule out the malignant transformation.

53. FIBROUS CORTICAL DEFECT Benign well circumscribed fibrous growth with in a small area of long bone. A/k/a nonossifying fibroma,fibroxanthoma Localised form of fibrous dysplasia. Age :- <30yrs Location :- metaphysis of long bone.-usually lower limb. Sex :-M:F=1:1 Clinical feature :- -usually asymptomatic -occasionally presents with pathological fracture.

54. FIBROUS CORTICAL DEFECT X ray findings :- -well defined lobulated lesion. - Ecentrically placed. -Cortex thinning & expansion - Multilocular appearance or ridges in bony wall. -No periosteal reaction. Treatment :- Excision & curettage

55. FIBROUS CORTICAL DEFECT Pathology :- Gross :- thin cortex enclose soft /tough rubbery gray –yellow or reddish brown tissue. Microscopic :- Spindle shaped cell distributed in a whorled pattern. Fibroblastic proliferation with high cellularity. Giant & foam cells are present.

56. BROWN TUMOR OF HYPERPARATHYROIDISM - Hyperparathyroidism results in disorder of bone & mineral metabolism. -Diffuse & focal lesion may arise in multiple bones. -These lesion are K/as brown tumours due to the presence of hemorrhage in the lesion. Location :- Any bone can be affected. Mainly diaphysis of long bone. Clinical features :- Stones Bones Groans

57. BROWN TUMOR OF HYPERPARATHYROIDISM Radiological features :- Salt & pepper skull Multiple osteolytic lesions Laboratory findings :- ↑ ed levels of PTH Hypercalcemia ↑ ed serum phosphate & urate . TREATMENT :- treatment of the primary cause will cause the healing of lesion.

58. Eosinophilic granuloma: EG is like osteomyelitis a great mimicker of benign and malignant bone tumors. Must be included in the differential diagnosis of almost any ill-defined osteolytic bone lesion in patients under the age of 30. May also present as a well-defined lesion. EG can be excluded in patients > 30 years. Either solitary bone involvement, multiple bone involvement (variable skin involvement) or multiple organ involvement (bone, liver, spleen, other sites)

59. Microscopy: Infiltration by Langerhans cells (polygonal cells with eosinophilic cytoplasm, oval nuclei with longitudinal grooves resembling coffee beans) Eosinophils, giant cells, neutrophils, foam cells, lymphocytes, plasma cells, fibrosis, necrosis; may have typical and atypical mitotic figures

60. Giant cell tumor: Giant cell tumor is a benign lesion Most commonly seen in age 20-40 years. A well-defined margin is associated with a locally less aggressive biologic behavior. In many cases the margin is ill-defined These tumors often thin the cortex and may expand into the soft tissues surrounding the bone.

61. Stromal cells are mononuclear, resemble macrophages Giant cells are large, multinucleated (10 - 50 nuclei) with similar nuclei as stromal cells

62. Treatment Surgical curettage (34% recur) or en bloc excision (7% recur); may implant into adjacent soft tissue Radiation therapy only if surgical excision impossible since it may promote malignant transformation

63. Osteosarcoma Most common primary bone tumor after myeloma 60% male; usually ages 10 - 25 years or ages 40+ with other diseases Sites: metaphysis of long bones (distal femur, proximal tibia, proximal humerus ; sites of peak mitotic activity for bone cells); occasionally diaphysis, rarely epiphysis ; less common in flat bones or short bones; usually arises within medullary cavity and extends to cortex

64. Osteosarcoma: Hallmark of osteosarcoma is the production of bony matrix, which is reflected by the sclerosis Usually typical malignant features including permeative-motheaten pattern of destruction , irregular cortical destruction and aggressive (interrupted) periosteal reaction. Radio: Large, destructive, lytic or blastic mass with permeative margins.May break through cortex and elevate periosteum.Sunburst pattern due to new bone formation in soft tissue Occasionally an osteosarcoma may present as a lytic or mixed lytic-sclerotic lesion. Completely lytic osteosarcoma may represent telangiectatic subtype, composed of multiple cavities filled with blood (may resemble aneurysmal bone cyst!).

65. mixed osteolytic and sclerotic lesion in the proximal humerus with irregular cortical destruction. There is an aggressive periosteal reaction and a soft tissue mass.

66. Gross: Big, bulky, gritty, hemorrhagic with cystic degeneration Spreads within medullary cavity, destroys cortical bone, elevates periosteum and invades soft tissue May form satellite nodules (“skip metastases”) Usually has well defined proximal and distal margins

67. Chondrosarcoma : Third most common bone malignancy after myeloma and osteosarcoma Usually ages 30 - 60 years, 75% males Most commonly presents as a well-defined lesion, but uncommonly it can be encountered as an ill-defined lytic lesion.

68. Partially ill-defined osteolytic lesion There are cloud-like calcifications indicating a chondroid matrix.

69. Pearly white or light blue, often with focal calcification May have small cysts or myxoid change

70. Micro: Tumor cells produce cartilaginous matrix Either well, moderate or poorly differentiated May have only minor or focal atypia , but consider malignant if malignant radiologic features Intracytoplasmic hyaline globules common in low grade tumors Grading: based on cellularity and nuclear changes in chondrocytes; well, moderate or poorly differentiated correspond to grades 1 - 3; grade 4 is spindled tumor representing either chondroblastic osteosarcoma or dedifferentiated chondrosarcoma

71. Mutiple myeloma: Multiple myeloma must be included in the differential diagnosis of any lytic bone lesion, either well-defined or ill-defined in age > 40. Most common presentation: multiple lytic 'punched out' lesions. A solitary presentation is referred to as plasmacytoma . Usually no increased uptake on bone scan. The most common location is in the axial skeleton (spine, skull, pelvis and ribs) and in the diaphysis of long bones (femur and humerus ).

72. Round lesions filled with a soft reddish material are indicative of foci of myeloma in this section of vertebral bone. Larger lesions may weaken the bone to cause fracture with back pain.

73. Micro:

74. Ewings sarcoma Most common presentation: ill-defined osteolytic lesion with multiple small holes in the diaphysis of a long bone in a child with a large soft tissue mass. Presentation with pain, mass, fever, anemia and leukocytosis. Most common location: femur, iliac bone, fibula, rib, tibia. Frequently aggressive type of periosteal reaction, but never a benign type.

75. Gross description White, fleshy, ill defined tumor with extensive involvement of medulla and cortex with periosteal elevation May be necrotic or resemble pus Excised specimen show fibrosis, hemorrhage and necrosis Necrosis can be used as a predictor of long term outcome

76. Micro: At lower power, is undifferentiated and densely cellular with "light" cell and "dark" cell appearance.Sheets of small, round, uniform cells with scant clear cytoplasm, divided into irregular lobules by fibrous strands.Indistinct cell membranes Minimal amounts of stroma

77. Metastasis : Must be considered in the differential diagnosis of any bone lesion in a patient > 40 years. May present as well-defined osteolytic , ill-defined osteolytic and also as sclerotic bone lesion. Majority of osteolytic metastases originate from lung, kidney, colon, melanoma. Cancer most commonly spreads to these sites in the skeleton: Vertebra,Pelvis , Ribs, Skull,Upper arm and Long bones of the leg

78. Case3 : 30 YEAR F PRESENTED WITH PAIN AND SWELLING IN THE KNEE JOINT SINCE 1 WEEK .PATIENT ALSO HAS FEVER SINCE 1 WEEK

79. Osteomyelitis : Osteomyelitis is the great mimicker of bone tumors. It has a broad spectrum of radiographic features and occurs at any age and has no typical location. In the chronic stage it can mimic a benign bone tumor ( Brodies abscess). In the acute stage it can mimic a malignant bone tumor with ill-defined margins, cortical destruction and an aggressive type of periostitis . Only when there is a thick solid periosteal reaction we can recognize the non-malignant underlying process

80. Case4:

81. Spotter:

82. “If I were you, I will run to the Radiology department and get the x-ray films and make them available before the Histology slides are studied” Prof. Peter G Bullough Professor of Orthopedic Pathology Hospital for Special Surgery, Cornell University, NEW YORK

83. Diagnosis of Cystic Tumours

84. Take home message: Following points to be kept in mind while reporting : History Age Location Multiple/single Radiological findings

85. References: 1.Orthopaedic pathology Vincent J Vigorita 2.Dahlin’s bone tumors 3. The Radiology Assistant : Bone tumor - well-defined osteolytic tumors and tumor-like lesions 4.https://radiopaedia.org 5.www.pathologyoutlines.com