GIANT CELL TUMOR Age: 20-40. Epiphyseometaphyseal in adults - Metaphyseal in adolescents. 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
HISTOPATHOLOGY:•Uniform oval mononuclear stromalcells : mesenchymal origin; neoplastic•Appear to grow in a syncytium•Numerous osteoclast-type giantcells: reactive•Necrosis, hemorrhage, hemosiderin deposition and reactive boneformation•Relatively few mitotic figures inrelation to the dense cellularity of thetumor
GIANT CELL VARIANTSIncludes 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
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) Multicentricity 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.
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.
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
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
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.
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
EWING’S SARCOMAJames Ewing 1921GROSS 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 around, no capsule
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)
OSTEOCHONDROMAGROSS 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
Painful osteochondroma: Fracture Bursitis Malignant transformation: fluffy calcification in the cartilage cap, thickness of cartilage cap > 1 cm.
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.
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
TUBERCULAR SPONDYLITIS (POTT’S) SPINE Paradiscal Loss of height of vertebra Caseating necrotic tissue Bone necrosis; sequestra Sclerosis
Kyphotic deformity Internal gibbus Severe cord compression
Granuloma or LH giant cell is not pathagnomonic of TB…!• Foreign body granuloma.• Fat necrosis.• Fungal infections.• Sarcoidosis.• Crohns disease.
• Granulomatous fungal disease; involve subcutaneous tissue after traumatic inoculation; later spread to deep structures.• Causes local tissue destruction including boneTypes:• Actinmycetoma: Actinomadura sps, Nocardia• Eumycetoma: Aspergillus sps,• Discharge colored granules: Red (Actinomadura pelletieri), white / yellow (Actinomadura madurae, Pseudoallescheria boydii), black (Exophiala jeanselmei, Madurella mycematis)• Pus contains sulfur granules, a tangled mass of branching bacteria (Splendore Hoppelli body)