ORTHOPAEDIC PATHOLOGICAL SPECIMEN AND HISTOLOGY

1. ORTHOPAEDIC PATHOLOGICAL SPECIMEN AND HISTOLOGY

2. DESCRIBING GROSS SPECIMEN A: Identify the part:  Knee / prox. femur/ prox. tibia/ pelvis /scapula.  Epiphyseal / Metaphyseal / Diaphyseal.  Physeal plate visible? – Immature pt.

3. B:Describe the abnormality:  Nature: solid / soft & friable /cystic / varigated  Matrix: bony / cartilaginous / fibrous  Secondary changes: central necrosis/ hemorrhage / cystic change  Cortical destruction, periosteal elevation  Intramedullary spread  Tumor margin / capsule: well defined / illdefined  Extension: into soft tissue / joint; invasion / infiltration to surrounding tissue

4. C: Give provisional diagnosis.

5. Epiphyseal • Chondroblastoma • Giant cell tumor • Diaphyseal • Ewing’s sarcoma • Myeloma, • Fibro sarcoma, • Reticulum cell sarcoma • Adamantinoma • Fibrous dysplasia • Osteoid Osteoma • Metaphyseal • Most others Ewing’s sarcoma Myeloma Osteoid osteoma Ewing’s sarcoma Myeloma Fibrous dysplasia Majority Chondroblastoma Giant cell tumor

6. Central • Enchondroma • Unicameral bone cyst • Round cell tumors • Cortical • Osteoid osteoma • Eccentric • Most other tumors • Enchondroma • Unicameral bone cyst • Round cell tumors • Majority

8. GIANT CELL TUMOR  Age: 20-40. Incidence : 5% of all bone neoplasm Sex : F:M = 2: 1 Bone Involved : Long tubular bones Distal femur  Prox tibia  Distal radius – UE Humerus  UE fibula  LE Ulna  Epiphyseal location (After epiphyseal closure)  Common location: around knee (50%), distal radius  Xray: Geographic lytic lesion, thinned & ballooned out cortex. Gross pathology:  Large red - grey - brown tumor  Soft & friable  Areas of cystic degeneration / necrosis & blood filled cavities

9. Soap bubble appearance

10. HISTOPATHOLOGY: •Uniform oval mononuclear stromal cells : mesenchymal origin •Appear to grow in a syncytium •Numerous osteoclast-type giant cells: reactive with centrally placed uniform size nuclei (40-100) •Necrosis, hemorrhage, hemosiderin deposition and reactive bone formation •Relatively few mitotic figures in relation to the dense cellularity of the tumor

11. GIANT CELL VARIANTS Includes the tumors which show giant cells in histology- A. ABC B. Brown tumor C. Chondromyxoid fibroma, chondroblastoma D. Desmoplastic fibroma E. Epulis – Giant cell reparative granuloma F. Fibrous dysplasia, non ossifying fibroma G. Giant cell rich osteosarcoma H. Benign fibrous histiocytoma        

12. Giant cell…… Physiological: Megakaryocyte Pathological  Langhans : fused epitheliod cells. Peripherally arranged 7-21 nuclei. TB, histoplasmosis, sarcoidosis, other mycobacteria  Foreign body: fused macrophages. Numerous nuclei scattered in cytoplasm Aschoff : Rheumatic heart disease Reed Sternberg: Hodgkin’s lymphoma Touton : xanthoma, xanthogranuloma, dematofibroma Viral: Warthin Finkeldy (measles), resp syncitial virus, parainfluenza Tumor     

13. Stromal cells Giant cells Grade-1 or conventional GCT Stroma less Large number Grade-II or Borderline GCT Prominent cellular atypia Decrease in number Grade-III or fully malignant Sarcomatous stroma Sparse • Features of malignant changes : • Size and number of giant cells decrease • Stroma shows : Heterogenicity as : Crowding, Plumping up, Increased chromatin, Increased mitotic figures. • Vascularity increases • Grading of GCT (Jaffe):

14. Campanacci’s Radiological Grading Grade I – Cystic lesion Grade II – Cortex thin but not perforated Grade III – Tumour extended into surrounding soft tissue Enneking’s Staging of Benign GCT

15. Treatment (Grade-I and Grade-II) • Only curettage. • Curettage + bone grafting. • Curettage + bone grafting + liquid nitrogen (cryosurgery). • Extended aggressive curettage + Phenol / argon beam coagulation / bone cementing. Grade-III – Resection + Reconstructions Resection : En Block (Joints lost) * Role of Radiation in GCT- spine/pelvis (1500-5000 rads for 5-6 wks)

16. Giant Cell Tumour

17. Giant CellTumour

18. OSTEOSARCOMA  Bimodal age distribution: Primary 10-20, secondary 50-70.  75% around knee  Bone forming tumor arising from bone  Several subtypes –  By location (Central or Juxtacortical) Degree of differentiation: well to dedifferentiated Histologic variance: osteoblastic/chondroblastic/fibroblastic/telangictatic/small cell  Associated with Retinoblastoma (rb gene), Li Fraumeni syndrome (p53 gene), Rothmund Thomsen syndrome.

19. GROSS PATHOLOGY:  Metaphyseal  Tan-white solid tumor fills most of the medullary cavity of the metaphysis and proximal diaphysis  Expanding & infiltrating through the cortex, lifts the periosteum (Codman’s triangle) and forms soft tissue masses on the side of the bone  Areas of hemorrhage and central necrosis.

20. HISTOPATHOLOGY:  Pleomorphic and anaplastic cell population- large hyperchromatic nuclei, mitotic figures  Abundant fibrous/ chondroid matrix  Formation of pink homogenous osteoid by neoplastic cell: characteristic.  The neoplastic bone has a coarse, lacelike architecture but is also deposited in broad sheets or as primitive trabeculae.  Osteoblastic, chondroblastic or fibroblastic types  Osteoclast-like giant cells may be present

21. Ewing’s Sarcoma

22. CHONDROSARCOMA  Age: 30-60  Primary or Secondary ( Enchondromatosis [Ollier 50%, Maffucci 100%], diaphyseal aclasis 20%, osteochondroma 0.25%)  Pelvis (30%), Femur (20%)  Types: Conventional, mesenchymal, clear cell, juxtacotical, dedifferentiated  Most common malignant bone tumor of hand

23. GROSS PATHOLOGY:  Large bulky tumor  Made up of lobules of gray-white /somewhat translucent glistening tissue. Tumor permeating throughout the medullary cavity, growing through the cortex, and forming a relatively well- circumscribed soft tissue mass. At center – necrotic/liquefied/cystic. Gelatinous appearance secondary to myxoid changes in matrix. May show calcification. The adjacent cortex is thickened or eroded, and the tumor grows with broad pushing fronts into the surrounding soft tissue.    

24. HISTOPATHOLOGY: • Tumor cells produce cartilaginous matrix; well, moderate or poorly differentiated. • May have only minor or focal atypia • Intracytoplasmic hyaline globules common in low grade tumors

25. EWING’S SARCOMA James Ewing 1921 GROSS PATHOLOGY:  Diaphyseal in long bones; also pelvis, rib, scapula  White tan grey mass like brain; or red like red currant gelly if hemorrhagic  With necrosis & hemorrhage  Cortical destruction  Invasion to soft tissue, no capsule

26. HISTOPATHOLOGY: Homogenous & densly packed undifferentiated small round blue cells like lymphocytes; regular nuclei, infrequent mitoses, scant clear cytoplasm. • • Abundant glycogen: PAS + diastase digestible • Rare Homer- Wright pseudorosettes (7-8 tumor cells arranged in a circle about a central fibrillary space)

27. D/D : Small Round Cell Tumor  Ewing’s: mic2 overexpression - CD99/013 . t(11;22)(EWS-FLI-1). NSE +  PNET (Primitive neuroectodermal tumor): CD99/013. S100, chromogranin, synaptophysin; > 20% Homer Wright rosettes  Lymphoma (reticulum cell sarcoma, NHL): CD 45, LCA  Small cell carcinoma: keratin, synaptophysin, chromogranin  Mesenchymal chondrosarcoma  Neuroblastoma: neurofilament. S100, chromogranin, synaptophysin.  Alveolar rhabdomyosarcoma: actin, desmin, vimentin, MyoD1, myogenin  Leukemia

28. Osteochondroma – • most common benign bone tumor • AGE: during growth period • SEX: Male • SITE Attachments near metaphysis OSTEOCHONDROMA GROSS PATHOLOGY:  Mushroom shaped  Cartilage-capped bony outgrowth  Cartilage cap usually regular and thin Sessile / Pedunculated Pedunculated : attached to skeleton by bony stalk; medullary cavity of the osteochondroma and bone are in continuity Diaphyseal aclasis: multiple heriditary exostosis Trevor’s disease: Epiphyseal side osteochondroma    

30. Painful osteochondroma:  Fracture  Bursitis  Malignant transformation: fluffy calcification in the cartilage cap, thickness of cartilage cap > 1 cm. Radiology Treatment

31. CHRONIC OSTEOMYELITIS  Sequestrum is the necrotic bone that is embedded in the pus/infected granulation tissue.  Involucrum is the new bone laid down by the periosteum that surrounds the sequestra.  Cloaca is the opening in the involucrum through which pus & sequestra make their way out.

32. Types of sequestrum….. Tubular: long bone Annular: amputation stump Ring: around pin tracts Flake, coke, rice grain: tubercular Button: histiocytosis Feathery: syphilis Match stick: sickle cell Coloured: fungal Black: gun shot Bombay: exposed bone after open fracture          

33. TUBERCULAR SPONDYLITIS (POTT’S) SPINE  Paradiscal  Loss of height of vertebra  Caseating necrotic tissue  Bone necrosis; sequestra  Sclerosis

34. Acute osteomylitis is most commonly caused by a)staphylococcus aureus b)H. influenzae c)Streptococcus d)Salmonella e) Pseudomonas

35. Earliest site of bone involvement in hematogenous osteomyelitis a)Metaphysis b)diaphysis c)Epiphysis d) Physis e)Point of entry of nutrient artery

36. Complications of acute osteomyelitis a)malignancy b)fracture of the affected bone c)sepsis d)chronicity

37. The most common organism causing osteomyelitis in drug abusers is a)E coli b)pseudomonas c)Klebsiella d)Staph aureus

38. Giant cell tumour is located in the? a) Epiphysisb) Metaphysisc) diaphysisd) all of the above

39. Soap bubble appearance is seen in which of the following tumours? a) Osteosarcomab) Chondrosarcomac) Osteoclastomad) Ewings sarcoma

41. A 15 year old boy is injured while playing cricket. X-rays of the leg rule out of a possible fracture. The radiologist reports the boy has an evidence of aggressive bone tumour with both bone destruction and soft tissue mass. The bone biopsy reveals a bone cancer with neural differentiation. Which of the following is the most likely diagnosis? a) Chondroblastomab) Ewing‘s sarcomac) Neuroblastomad) Osteosarcoma

42. Both Ewing sarcoma and peripheral neuroepithelioma belong to the Ewing family of tumors and are considered neural tumors . Unlike neuroblastoma, these neural tumors are not derived from the sympathetic system, and catecholamine metabolites are not excreted in the urine . In vitro, these tumors show neural differentiation and have neural features. Results with neuron-specific enolase and S-100 protein testing are positive. electron microscopy reveals neural structures such as neurites and dense-core granules. Glycogen granules are present, and alkaline phosphatase is absent.

43. Neuroblastoma (NB) is the most common extracranial solid cancer in childhood and the most common cancer in infancy It is a neuroendocrine tumor, arising from any neural crest element of the sympathetic nervous system (SNS). It most frequently originates in one of the adrenal glands, but can also develop in nerve tissues in the neck, chest, abdomen, or pelvis.

45. CHONDROBLASTOMA Although it can affect people of all ages, it most often appears in males younger than 25 years old. Biopsy and hematoxylin and eosin (H&E) staining under high light microscopy magnification show numerous chondroblastic cells embedded in a highly mesenchymal cartilaginous matrix. Chicken-wire calcification in a latticelike pattern surrounding the tumor cells is present in 30% of chondroblastomas.

46. Malignant tumour of mesenchymal cells characterized by formation of osteoid is description fit for ? a) Osteosarcomab) Chondrosarcomac) Osteoclastomad) Ewings sarcoma

47. Secondary osteosarcoma can be caused after? a) Pagets diseaseb) fibrous dysplasiac) multiple enchondromatosisd) All the above

48. Causes of secondary osteosarcoma: 1- Radiation 2- Bone Diseases: a) Pagets disease b)Hereditary multiple osteochondroma c)Enchondromatosis d) Fibrous dysplasia 3- Inherited Cancer Syndromes: a) Li–Fraumeni syndrome b) Rothmund-Thomson syndrome c) Hereditary retinoblastoma d) Bloom syndrome e) Werner syndrome f) Diamond-Blackfan anemia

49. Most common site of metastasis in Osteosarcoma is ? a) Lungsb) Heartc) Braind) Liver

50. True statement about involucrum and sequestrum: a) Involucrum is a piece of dead bone b) Sequestrum is a sheath of new bone formation c) Sequestrum is surrounded by involucrum d) Involucrum is surrounded by sequestrum