Lytic lesions of bone

Brief on lytic lesions of bone.

1. LYTIC LESIONS OF BONE Presented by: Dr. Devraj Kandel Resident , MDRD, NAMS

2. INTRODUCTION The lytic lesions in bones may be a manifestation of a number of bone tumors as well as tumor like conditions that are common in day to day practice. Plain radiography is the modality of choice in the diagnosis. Other imaging modalities: To better elicit or delineate characteristics demonstrated on X-ray To precisely define the extent of lesion To exclude metastasis

3. CT: Assessment of primary lesion and detection of potential metastatic dissemination Predominant tissue present e.g., fat and calcification Intra-osseous and extra-osseous extent of tumor, subtle change in medulla and cortical erosion Vascular nature of tumor and relation with vascular structures Detects more pulmonary metastasis.

4. MRI: Provides good soft tissue contrast with multiplanar imaging. Better detection of medullary changes, intra and extra osseous extent, relation with neurovascular bundle and joints. Thus helps to stage and plan surgery. Measure of tumor aggressiveness by Gd administration. Rate of accumulation of contrast correlates with biological activity. Helps in monitoring the tumors' response to appropriate adjuvant chemotherapy.

5. ANGIOGRAPHY : Delineation of involvement of major vessels and for tumor embolisation. Tumor encasement and tumor vessels-much greater frequency in malignant. ( Encasement-vessel surrounded by tumor causing abrupt narrowing ). Tumor vessels-structures pursuing random course with an irregular branching pattern.

6. SCINTIGRAPHY : May be used as first additional modality depending on the availability of CT and MRI. To assess the primary lesion and to see whether it is monoostotic or polyostotic. To assess the vascularity of the lesion. Provides extension of lesion beyond the confines of x ray.

7. Lytic lesions: FEGNOMASHIC

8. FIBROUS DYSPLASIA Benign congenital process that can be seen in a patient of any age and can look like almost any pathologic process radiographically. Fibrous dysplasia will not have periostitis associated with it; therefore, if periostitis is present, one may safely exclude fibrous dysplasia. Fibrous dysplasia virtually never undergoes malignant degeneration and is painless unless there is a fracture. can be either monostotic (most commonly) or polyostotic and has a predilection for the pelvis, proximal femur, ribs, and skull.

9. When it is present in the pelvis, it is invariably present in the ipsilateral proximal femur. Typically has an expansile, lytic appearance in the posterior ribs and a sclerotic appearance in the anterior ribs. Discriminator of fibrous dysplasia: No periosteal reaction.

10. Adamantinoma : When a lesion is encountered in the tibia that resembles fibrous dysplasia, an adamantinoma should also be mentioned. An adamantinoma is a malignant tumor that radiographically and histologically resembles fibrous dysplasia. It occurs almost exclusively in the tibia and the jaw (for unknown reasons) and is rare.

11. Fig. Adamantinoma of the tibia. Eccentric areas of bone destruction are present anteriorly with thinning of the cortex. The cortex is expanded. In addition to this abnormality, sclerosis and ill-defined cortical thickening are present throughout the whole of the tibia, which is also bowed. These features are due to associated fibrous dysplasia (or a close variety sometimes known as ossifying fibroma which occurs only at this site). (A) AP view. (B) Lateral view.

12. McCune Albright Syndrome. Polyostotic fibrous dysplasia occasionally occurs in association with cafe au lait spots on the skin (flat pigmented skin lesions) and precocious puberty. This complex is called McCune–Albright syndrome.

13. The presence of multiple lesions of fibrous dysplasia in the jaw has been termed cherubism . This is from the physical appearance of the child with puffed-out cheeks having an angelic look. The jaw lesions in cherubism regress in adulthood.

14. ENCHONDROMA Enchondromas occur in any bone formed from cartilage and may be central, eccentric, expansile, or nonexpansile. They invariably contain calcified chondroid matrix except when in the phalanges of the hands and feet. Most common benign lytic lesion in the phalanges. Discriminators: Must have calcification (except in phalanges), No periostitis or pain.

15. Differentials: Bone infarcts Chondrosarcoma An infarct usually has a well-defined, densely sclerotic, serpiginous border whereas an enchondroma does not. An enchondroma often causes mild endosteal scalloping , whereas a bone infarct will not.

16. It is difficult, to differentiate an enchondroma from a chondrosarcoma. Clinical findings (primarily pain) serve as a better indicator than radiographic findings- usually absent in enchondroma. Multiple enchondromas occur on occasion; this condition has been termed Ollier disease . It is not hereditary and carries a low risk of malignant degeneration. The presence of multiple enchondromas associated with soft tissue hemangiomas is known as Maffucci syndrome .This syndrome also is not hereditary, is quite rare, and carries a higher risk of malignant degeneration of both the enchondromas and the hemangiomas, as well as an increased risk for developing other malignancies.

17. EOSINOPHILIC GRANULOMA Eosinophilic granuloma (also known as LCH of bone) is the most common and least severe form of Langerhans cell histiocytosis, the other forms being Letterer–Siwe disease and Hand–Schuller–Christian disease . Bony manifestations of all three disorders are similar. Can be lytic or sclerotic; well defined or ill defined; might or might not have a sclerotic border; and might or might not elicit a periosteal response. Can mimic Ewing sarcoma and present as a permeative (multiple small holes) lesion. Occurs almost exclusively in patients less than the age of 30 years (usually <20 years); therefore, the patient’s age is the best criterion.

18. Because EG can look like anything, so long as the radiograph is not of an arthritides or trauma, EG can be mentioned without even looking at the radiograph! EG is most often monostotic , but it can be polyostotic. EG might or might not have a soft tissue mass associated. EG occasionally has a bony sequestrum. Other entities which may have bony sequestra—osteomyelitis, lymphoma, and fibrosarcoma; Therefore, when a sequestrum is identified, EG, osteomyelitis, lymphoma, and fibrosarcoma should be considered. Clinically, EG might or might not be associated with pain; therefore, clinical history is noncontributory for the most part.

19. GIANT CELL TUMOR Uncommon tumor found almost exclusively in adults in the ends of long bones and in flat bones. Difficult to tell whether it is benign or malignant regardless of its radiographic appearance and even by histology Most surgeons curettage and pack the lesions and consider them benign if they do not recur. When malignant, they metastasize to lungs, but do so very infrequently. Four classic radiographic criteria for diagnosing giant cell tumors exist. If any of these criteria are not met when looking at a lesion, giant cell tumor can be eliminated from the differential diagnosis.

20. Four Criterias : (Discriminators). Physes must be closed, Must abut the articular surface (this rule does not apply to flat bones such as in the pelvis or in the apophyses which have no articular surfaces), Must be well defined with a nonsclerotic margin (does not apply is in flat bones, such as the pelvis and the calcaneus ), Must be eccentric.

21. These 4 criteria apply only to giant cell tumor and not to any other lesion, once one of the criterias is violated, the remainder don’t even have to be used to exclude a giant cell tumor. However, it should be emphasized that these criteria only apply to giant cell tumors of long bones. They would not work, for instance, in the sacrum, pelvis, or the calcaneus , three locations where giant cell tumors often occur.

22. Giant Cell Tumor . A well-defined lytic lesion without a sclerotic margin is seen abutting the articular surface of the distal femur in a patient who has closed epiphyses. These are all characteristics of a giant cell tumor

23. NONOSIFYING FIBROMA An NOF (also known as a fibroxanthoma ) is probably the most common bone lesion encountered by radiologists. They are benign, asymptomatic lesions that typically occur in the metaphysis of a long bone, emanating from the cortex. They classically have a thin, sclerotic border that is scalloped and slightly expansile. “ Fibrous cortical defect ” is a common synonym, although some people divide the two lesions on the basis of size, with a fibrous cortical defect being smaller than 2 cm in length and an NOF being larger than 2 cm. If a CT or MR is obtained of an NOF, there will often appear to be interruption of the cortex, which can be misinterpreted as cortical destruction- which actually represents cortical replacement by benign fibrous tissue.

24. If the patient is older than 30 years of age, NOF should not be included in the differential diagnosis. NOFs must be asymptomatic and exhibit no periostitis, unless there is a history of antecedent trauma. They routinely “heal” with sclerosis and eventually disappear, usually around the ages of 20 to 30 years. During this healing period, they can appear hot on a radionuclide bone scan because there is osteoblastic activity. They are most commonly seen about the knee but can occur in any long bone. Discriminators: Must be younger than age 30 years, No periostitis or pain.

25. Fig: Nonossifying Fibroma. A: A well-defined, lytic lesion that is minimally expansile is seen in the distal tibia in this child who was examined for a sprained ankle. B: A CT examination showed apparent cortical destruction (arrow), which was believed to be suggestive of an aggressive lesion. Biopsy showed this to be a nonossifying fibroma. Both CT and MR will often show apparent cortical destruction, which is merely cortical replacement by benign fibrous tissue.

26. OSTEOBLASTOMA Osteoblastomas have two appearances They look like large osteoid osteomas and are often called giant osteoid osteomas . (not included in differential of lytic lesions) They simulate ABCs. They are expansile, often having a soap bubble appearance. If an ABC is being considered, so should an osteoblastoma. The latter form of osteoblastomas commonly occur in the posterior elements of the vertebral bodies, and about half of the cases demonstrate speckled calcifications. A classic radiology differential is that of an expansile lytic lesion of the posterior elements of the spine, which includes osteoblastoma, ABC, and tuberculosis .

27. METASTATIC DISEASE Metastatic disease should be considered in d/d of any lytic lesions in >40yrs Can have any radiographic appearance-lytic, sclerotic or mixed. Mostly lytic, prostate- purely sclerotic, renal – purely lytic. Discriminator: Age>40yrs.

28. FIGURE . Metastatic Disease. An expansile lesion with a soap-bubble appearance is present in the proximal radius in a patient with renal cell carcinoma. An expansile lytic lesion is a common finding with renal or thyroid metastatic disease.

29. MULTIPLE MYELOMA Most commonly presents as a diffuse permeative process in a skeleton. Can present as solitary or multiple lytic lesions. Bubbly, lytic bone lesions of myeloma are more correctly called plasmacytomas. Plasmacytomas involving a vertebral body often have a characteristic appearance on CT and MRI called a “ mini-brain ”. Unlike metastatic disease, lymphoma, and infection, when plasmacytomas involve a vertebral body they tend to spare some of the bone; struts of cortical bone persist, giving the pathognomic appearance of a cut brain specimen.

30. FIGURE 55.26. Multiple Myeloma. A: A diffuse permeative pattern is present throughout the femur in this patient with multiple myeloma. B: A lateral skull radiograph shows a typical presentation of multiple myeloma in the skull with multiple small well-defined lucent lesions throughout the calvarium .

31. ABC Named after the macroscopic appearances of a blood-filled, expansile , sponge-like tumour containing numerous giant cells. Primarily seen in less than the age of 30 years. ABCs typically present because of pain. Can occur anywhere in the skeleton but has a predilection for the long bones and the lumbar spine (posterior elements). Two types of ABCs: Primary ABC- no known cause or association. Secondary ABCs- occur with GCTs, osteosarcomas , NOFs, fibrous dysplasia and chondromyxoid fibromas .

32. Often have fluid/fluid levels on CT or MRI. Differentiation from GCTs is aided by the age of the patient, (most occur before epiphyseal fusion), and their widespread anatomical distribution(most GCTs occurring around the knee and wrist). ABC rarely extends to the articular surface and is often central, contrast to GCTs. The spinal lesions need to be differentiated from osteoblastoma and osteoid osteoma (latter two are bone forming and show sclerotic reactions). Discriminators: Must be expansile , Must be younger than age 30 years.

33. FIG. Aneurysmal Bone Cyst (ABC). An expansile lytic lesion is present in the distal femur in this 24-year-old patient who presents with pain. This is a fairly typical appearance of an ABC.

34. FIGURE 55.31. Aneurysmal Bone Cyst (ABC). A well-defined expansile lesion is seen in the midshaft of the ulna in a child who presents with pain in this region. This is a characteristic appearance of an ABC.

35. SIMPLE BONE CYST Also called solitary bone cysts or unicameral bone cysts. Occur almost exclusively in young patients (<30 yrs). Always central in location . Common sites: Proximal humerus , Proximal femur, Calcaneum . Asymptomatic unless fractured. Classic radiographic finding for a solitary bone cyst is the fallen fragment sign. Begin at the physeal plate in long bones and grow into the shaft of the bone.

36. On bone scanning no abnormality develops in the blood pool phase, in contrast to aneurysmal bone cysts. The delayed image demonstrates increased activity only around the margins of the lesion, unlike fibrous dysplasia. The only serious differential diagnostic possibility is a chondroma , but no calcification occurs in a simple bone cyst unless callus has formed from a fracture. Discriminators: Must be central Must be younger than age 30 years.

37. FIG. Solitary Bone Cyst. A well-defined lytic lesion is present in the proximal humerus in this child who suffered a fracture through the lesion. The location and central appearance , as well as the age of the patient, are characteristic of a solitary bone cyst. A piece of cortical bone has broken off and descended through the serous fluid contained within the lesion and can be seen in the dependent portion of the lesion (arrow) as a fallen fragment sign . A fallen fragment sign is said to be pathognomonic for a unicameral bone cyst.

38. FIG. Solitary Bone Cyst. A well-defined lytic lesion, which is central in location, is seen in the proximal femur in this child. This is characteristic of a solitary bone cyst

39. FIG. Solitary Bone Cyst. A well-defined lytic lesion is seen in the calcaneus abutting the inferior surface, which is typical in location and appearance for a solitary bone cyst. A solitary bone cyst in the calcaneus occurs almost exclusively in this location and is not subject to pathologic fracture as readily as when one occurs in the proximal femur and humerus .

40. HYPERPARATHYROIDISM Osteitis Fibrosa Cystica or Von Recklinghausen’s disease of bone; also called as brown tumor. So called because of brownish color due to hemorrhage and altered blood. Vascularized fibrous tissue with giant cells replaces the bone resulting cystic (lytic) lesion. May destroy overlying cortex resulting in pathological fracture. Generally when patient’s HPT is treated, the brown tumor undergoes sclerosis and will eventually disappear. Subperiosteal resorption is pathognomic and should be sought for in radial aspect of middle phalanges, distal clavicle, medial aspect of proximal tibia and SI joint. Discriminator.: Must have other evidence of HPT.

41. FIG. Brown Tumor. A: An expansile lytic lesion is seen in the fifth metacarpal (arrows), and a second, smaller lytic lesion is seen in the proximal portion of the fourth proximal phalanx. This patient can be noted to have subperiosteal bone resorption, best seen in the radial aspect of the middle phalanges (B) (arrows) as indistinct, interrupted cortex. This makes the diagnosis of hyperparathyroidism with multiple brown tumors most likely

42. HEMANGIOMAS Multiple hemangiomas , also known as cystic angiomatosis or cystic lymphangiomatosis , while uncommon, are seen more frequently than brown tumors. Usually an incidental finding of multiple lytic lesions throughout the skeleton. Without destructive potential. Should be considered when multiple lytic lesions are encountered which are asymptomatic. Discriminator: Multiple lesions.

43. FIG. Cystic Angiomatosis . Multiple lytic lesions are seen in the pelvis and femurs in this asymptomatic young woman. These were found to be hemangiomas .

44. INFECTION No reliable radiographic way to exclude a focus of infection. Can occur in any location and at any age. Might and might not be expansile , might or might not have sclerotic border or have associated periostitis . When osteomyelitis occurs near jt and if articular surface is abutted-invariably joint will be involved and show cartilage loss and effusion or both. Though effusion is seen in various other conditions, it is useful to rule out osteomyelitis when articular surface is involved and there is no effusion. If a bony sequestrum is present, it should be strongly suspected.

45. FIG. Osteomyelitis . A: A lytic lesion is present in the proximal humerus , which has some associated periostitis laterally. B: A CT scan through this area reveals a lytic lesion that contains a calcific density within (arrow), which is a bony sequestrum . This is an area of osteomyelitis with a bony sequestration.

46. CHONDROBLASTOMA Rare lesion , seen in epiphyses (very rare in metaphysis ) and in patients less than 30 years of age. 40% to 60% demonstrate calcification. D/d of a lytic lesion in the epiphysis of a patient less than 30 years of age is simple: infection (most common), Chondroblastoma giant cell tumor The carpal bones, the tarsal bones, the patella and the apophyses (except for geodes)have a tendency to behave like epiphyses in their d/d of lesions. Therefore, a lytic lesion in these areas has a similar d/d as an epiphyseal lesion.

47. The possibility of a subchondral cyst or geode should always be considered in epiphyseal lesions which is commonly seen in conditions like, Degenerative joint disease (must have joint space narrowing, sclerosis, and osteophytes ) Rheumatoid arthritis Calcium pyrophosphate dihydrate crystal deposition disease or pseudogout Avascular necrosis Discriminators: Must be less than 30 years of age Must be epiphyseal .

48. Fig:Chondroblastoma . A plain film in this young patient shows a well-defined lytic lesion in the greater tuberosity of the humerus . Biopsy showed this to be chondroblastoma .

49. Fig: Geode. A large, well-defined lytic lesion in the proximal humerus is present, which is associated with marked degenerative disease of the glenohumeral joint. When definite degenerative joint disease is present and associated with a lytic lesion, the lytic lesion should be considered to be a geode.

50. CHONDROMYXOID FIBROMA Rare lesion resembling NOFs. Although chondromyxoid fibromas are cartilaginous lesions, calcified cartilage matrix is virtually never seen radiographically . Features differentiating them from NOFs are; can be seen in a patient of any age (NOFs<30) often extend into the epiphyses (NOFs do not) can present with pain (NOFs are painless unless #) Discriminators: Mention when an NOF is mentioned No calcified matrix

51. FIG. Chondromyxoid Fibroma . A well-defined lytic lesion in the distal tibia that extends slightly into the epiphysis is noted on this anteroposterior radiograph. A nonossifying fibroma (NOF) could certainly have this appearance; however, this underwent biopsy and was found to be a chondromyxoid fibroma . Chondromyxoid fibromas often will extend into the epiphysis, as in this example, whereas NOFs usually will not.

52. LESIONS IN PATIENTS YOUNGER THAN 30 YEARS OF AGE “CANES” Chondroblastoma ABC NOF EG Solitary bone cyst

53. AUTOMATICS Yonger than 30 years Infection EG Older than 30 years Infection Metastasis and Myeloma

54. LESIONS THAT HAVE NO PAIN OR PERIOSTITIS “FENS” Fibrous Dysplasis Enchondroma NOFs Solitary bone cyst When we have good FriENdS , we experience less pain in life.

55. EPIPHYSEAL LESIONS Infection Giant Cell Tumor Chondroblastoma Geodes

56. DIFFERENTIAL FOR RIB LESIONS “FAME” Fibrous Dysplasia ABC Metastatic disease and Myeloma Enchondroma and EG

57. MULTIPLE LESIONS “FEEMBI” Fibrous Dysplasia Enchondroma EG Metastatic disease and Myeloma Hyperparathyroidism (Brown Tumor) Infection

58. References Brant and Helms’ Fundamentals of Diagnostic Radiology, 5 th edition Textbook of radiology and Imaging , David Sutton, 7 th edition.

59. Thank you !!!

60. Questions Name few osteolytic lesions of periphery Imaging modalities Differential diagnosis of lesions according to age Differential diagnosis of lesions according to location D/ds of multiple lytic lesions Finding in Fibrous dysplasia . Imaging finding in Enchondroma. Imaging finding in Giant cell tumor. Imaging finding in Non ossifying fibroma. Imaging finding in ABC. Imaging finding in simple bone cyst. Finding in brown cyst.