Which statement best describes the histogenesis of a 'mixed tumor' such as pleomorphic adenoma of the salivary gland?
- A It contains epithelial components dispersed within a myxoid stromal background, all derived from a single neoplastic clone ✓
- B It contains two distinct malignant clones, one epithelial and one mesenchymal, that collided within the gland
- C It represents a benign tumor arising from more than one germ cell layer
- D It shows divergent differentiation of a germ cell tumor into somatic tissues
Correct answer: A. It contains epithelial components dispersed within a myxoid stromal background, all derived from a single neoplastic clone
Explanation
Pleomorphic adenoma is composed of epithelial elements arranged in cords or islands within a myxoid, sometimes chondroid stromal background, and molecular studies show all components derive from a single clone of myoepithelial-origin cells capable of dual differentiation. Option C describes a teratoma and option D describes somatic transformation of a germ cell tumor, while a collision tumor (option B) involves two independent primaries meeting, none of which applies here.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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