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Anatomic pathology > Bones & Joints > Flashcards

Flashcards in Bones & Joints Deck (253)
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210

Fibrous dysplasia: Histology of periphery.

Reactive bone with osteoblastic rimming.

211

Fibrous dysplasia: Histologic variation.

Foci of cartilaginous differentiation: Fibrocartilaginous dysplasia.

212

Fibrous dysplasia: Affected gene.

GNAS1.

213

Fibrous dysplasia: Complication.

Fibrosarcoma, osteosarcoma, chondrosarcoma, or MFH may arise from it.

214

Fibrous dysplasia vs. desmoplastic fibroma.

Desmoplastic fibroma: No woven bone.

215

Osteofibrous dysplasia: Synonym.

Ossifying fibroma of long bones.

216

Osteofibrous dysplasia: Age group.

Mostly children under the age of 5 years.

217

Osteofibrous dysplasia: Sites.

Anterior surface of tibia or of fibula.

218

Osteofibrous dysplasia: Histology (3).

Similar to that of fibrous dysplasia but with

- Osteoblastic rimming.
- Simpler shapes of trabeculae.
- Maturation of bone.

219

Osteofibrous dysplasia: Radiography.

Cortical; diaphysis.

220

Osteofibrous dysplasia vs. osteosarcoma.

Osteosarcoma: The stromal spindle cells show nuclear atypia.

221

Osteofibrous dysplasia: Complication.

No known malignant transformation.

222

Nonossifying fibroma: Synonyms (2).

Fibrous cortical defect.

Metaphyseal fibrous defect.

223

Nonossifying fibroma: Typical presentation.

Asymptomatic.

224

Nonossifying fibroma: Radiography.

Cortical; metaphyseal; lytic lesion with sclerotic margin.

225

Nonossifying fibroma: Histology (4).

Fibroblastic spindle cells, sometimes in a storiform pattern.

Few mitotic figures.

Changes reminiscent of aneurysmal bone cyst.

Foci of necrosis or of reactive bone.

226

Nonossifying fibroma vs. benign fibrous histiocytoma.

Benign fibrous histiocytoma:

- Identical histology.
- Term used when lesion occurs in ribs, vertebrae, or flat bones.

227

Nonossifying fibroma: Syndromes (2).

Neurofibromatosis.

Jaffe-Campanacci syndrome.

228

Desmoplastic fibroma: Sites.

Chin.

Pelvis.

Humerus.

Femur.

Tibia.

229

Desmoplastic fibroma: Histology.

Resembles a fibromatosis set among bony trabeculae.

230

Desmoplastic fibroma: Cytogenetics.

+8, +20.

231

Desmoplastic fibroma vs. low-grade fibrosarcoma.

The latter diagnosis should be considered if there are more than rare mitotic figures.

232

Fibrosarcoma: Histology of grade 1 (3).

Bland fibroblasts.

No more than 4 mitotic figures per hpf.

Much collagen.

233

Fibrosarcoma: Histology of grade 2 (3).

More nuclear atypia.

More mitotic figures.

More cells; less collagen.

234

Fibrosarcoma: Histology of grade 3 (3).

Markedly atypical nuclei with large nucleoli.

Brisk mitotic activity, with atypical forms.

Necrosis, hemorrhage, myxoid change.

235

Fibrosarcoma: Mutation.

Gain of PDGFB at 22q12-q13.

236

Fibrosarcoma vs. desmoplastic fibroma (3).

Desmoplastic fibroma:

- Storiform rather than herringbone pattern.
- Contains tumor osteoid.
- No mitotic activity, no pleomorphism.

237

Fibrosarcoma: Most common antecedent.

Irradiation of a giant-cell tumor of bone.

238

Malignant fibrous histiocytoma: Iatrogenic antecedents (2).

Irradiation of bone.

Metallic prosthesis.

239

Malignant fibrous histiocytoma: Most common types seen in bone.

Storiform-pleomorphic.

Giant-cell-rich.