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Primary Intraosseous Carcinoma — MFDS Part 1 MCQ

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HardOral PathologyPrimary Intraosseous CarcinomaMFDS Part 1

Biopsy of a destructive posterior mandibular lesion shows squamous cell carcinoma. The overlying oral mucosa is intact, imaging demonstrates that the tumour arose centrally within the jaw, and clinical investigation identifies no primary carcinoma elsewhere. What is the presumed histogenetic source of this primary intraosseous carcinoma?

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Correct answer: C — Odontogenic epithelium persisting within the jaw

The correct answer is C. Primary intraosseous carcinoma is a squamous carcinoma arising centrally within a jaw and is presumed to originate from odontogenic epithelium, such as dental-lamina remnants, epithelial rests or the lining of an odontogenic cyst. The intact mucosa and absence of another primary tumour help distinguish it from direct invasion by oral squamous cell carcinoma and from metastatic carcinoma, excluding B. Intraosseous salivary epithelium may give rise to salivary-type lesions such as central mucoepidermoid carcinoma, not conventional primary intraosseous squamous carcinoma. Marrow precursors produce haematological malignancies, while endothelial cells produce vascular malignancies such as angiosarcoma.

Reference: Jain A, John S, Verma S, Gupta S. Navigating controversies in primary intraosseous carcinoma: A comprehensive literature review concerning the odontogenic origin and diagnostic challenges. Seminars in Diagnostic Pathology. 2025;42(1):50-54. https://pubmed.ncbi.nlm.nih.gov/39843327/