Fibrous Dysplasia Histology — MFDS Part 1 MCQ

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ModerateOral PathologyFibrous Dysplasia HistologyMFDS Part 1

A biopsy of an expansile jaw lesion shows bland cellular fibrous stroma containing irregular, discontinuous curvilinear trabeculae of woven bone. At the periphery, the lesional bone blends with the adjacent normal bone rather than forming a capsule. What is the most likely diagnosis?

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Correct answer: E — Fibrous dysplasia

The diagnosis is fibrous dysplasia. Its characteristic morphology is a bland fibroblastic stroma containing irregular, discontinuous and curvilinear trabeculae of woven bone, often described as resembling Chinese characters. The lesion characteristically blends into surrounding bone rather than being encapsulated. Ossifying fibroma is the principal distractor but is usually sharply demarcated or encapsulated and may contain more varied bone or cementum-like deposits. Paget disease produces disordered lamellar bone with prominent reversal lines and a mosaic pattern. Osteosarcoma requires malignant cytological features and tumour osteoid. Cementoblastoma forms a mineralised mass fused to a tooth root rather than a diffuse blending fibro-osseous lesion.

Reference: Szymczuk V, Taylor J, Boyce AM. Craniofacial Fibrous Dysplasia: Clinical and Therapeutic Implications—histologic features of craniofacial fibrous dysplasia. Current Osteoporosis Reports. 2023;21:147–153. https://pubmed.ncbi.nlm.nih.gov/36849642/