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Anatomic pathology > Bones & Joints > Flashcards

Flashcards in Bones & Joints Deck (253)
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150

Intramedullary chondrosarcoma: Significance of endochondral ossification.

Endochondral ossification does not make it an osteosarcoma.

151

Intramedullary chondrosarcoma vs. benign cartilaginous tumor: Anatomical clue.

Hands and feet: Generally benign.

Axial skeleton: Usually aggressive.

152

Intramedullary chondrosarcoma vs. benign cartilaginous tumor: Clinical clue.

If pain, then more likely to be malignant.

153

Secondary chondrosarcoma: Backgrounds (4).

Fibrous dysplasia.

Enchondromatosis.

Maffucci's syndrome.

Osteochondroma.

154

Dedifferentiated chondrosarcoma: Age group.

Most patients are older than 50 years.

155

Dedifferentiated chondrosarcoma: Presentation.

Recent increase in pain due to rapid growth of tumor.

Pathologic fracture in most patients.

156

Dedifferentiated chondrosarcoma: Radiography.

Poorly defined lytic area.

Superimposed radiodensity containing calcifications.

157

Dedifferentiated chondrosarcoma: Gross pathology.

Component of chondroid tissue.

Component of soft, fleshy, tan-yellow tissue.

158

Dedifferentiated chondrosarcoma: Histology.

Abrupt transition between

- Chondroid component: Grade 1 chondroid neoplasm (usually) or grade 2.
- Dedifferentiated component: Sarcomatoid, sometimes with heterologous differentiation.

159

Dedifferentiated chondrosarcoma: Immunohistochemistry (2).

Chondroid component express S100.

Dedifferentiated component expresses sarcoma-related markers (e.g. SMA, CD68).

160

Dedifferentiated chondrosarcoma: Ploidy.

Chondroid component: Diploid.

Dedifferentiated component: Aneuploid.

161

Dedifferentiated chondrosarcoma vs. mesenchymal chondrosarcoma (2).

Mesenchymal chondrosarcoma:

- More gradual transition between components.
- Hemangiopericytoma-like vascular pattern.

162

Dedifferentiated chondrosarcoma: Prognosis.

Dedifferentiated chondrosarcoma containing MFH component has a worse prognosis than primary MFH.

163

Mesenchymal chondrosarcoma: Age group.

About 80% of cases occur between 10 and 40 years of age.

164

Mesenchymal chondrosarcoma: Sites (5).

Maxilla.

Mandible.

Ribs.

Vertebrae.

Pelvis.

165

Mesenchymal chondrosarcoma: Radiography.

Radiolucency with variable mineralization.

166

Mesenchymal chondrosarcoma: Histology.

Gradual transition between

- Chondroid component: Bland hyaline cartilage.
- Mesenchymal component: Small round blue cells primitive spindle cells surrounding vessels like those of HPC.

167

Mesenchymal chondrosarcoma: Immunohistochemistry (5).

Chondroid component expresses S100.

Mesenchymal component
- Expresses Sox9.
- May express CD99 in small cells.
- May express NSE in primitive cells.
- Expresses desmin and MSA is there is rhabdomyoblastic differentiation.

168

Mesenchymal chondrosarcoma: Translocations (2).

t(11;22)(q24;q12) as in Ewing's sarcoma.

t(13;21)(q10;q10) in some tumors.

169

Clear-cell chondrosarcoma: Sites (3).

Epiphyseal:

- Proximal femur.
- Proximal humerus.
- Distal femur.

170

Clear-cell chondrosarcoma: Radiography (2).

Discrete lytic lesion with a sclerotic rim.

Cortex is usually intact.

171

Clear-cell chondrosarcoma: Cytology (3).

Nucleus:
- Vesicular chromatin.
- Large nucleolus.

Cytoplasm:
- Abundant, clear.
- Discrete borders.

Few mitotic figures.

172

Clear-cell chondrosarcoma: Histology

Chondroid matrix.

Scattered bony trabeculae or woven bone in the matrix.

Half of cases contain conventional chondrosarcoma.

173

Clear-cell chondrosarcoma: Special stain.

PAS highlights glycogen in the clear cells.

174

Clear-cell chondrosarcoma vs. chondroblastoma (2).

Chondroblastoma:

- Few or no clear cells.
- No bony trabeculae.

175

Hemangioma of bone: Sites (2).

Cranial bones.

Vertebrae.

176

Hemangioma of bone: Presentations (2).

Often symptomatic.

May compress facial nerve, spinal cord, or spinal nerve roots.

177

Hemangioma of bone: Radiography of cranial tumors (2).

Lytic mass with sunburst pattern.

Bulging of inner and outer tables.

178

Hemangioma of bone: Radiography of vertebral tumors (2).

Lytic mass with vertical striations.

CT: "Polka-dot" pattern.

179

Hemangioma of bone: Types.

Cavernous.

Cavernous + capillary.

Pure capillary (rare).