Which characteristic of a neoplasm distinguishes a high-grade dysplasia (carcinoma in situ) from invasive carcinoma on histology?
- A Presence of nuclear pleomorphism and mitotic figures
- B Lymphovascular permeation by tumor cells
- C Intact basement membrane with no stromal invasion ✓
- D Tumor necrosis and desmoplastic stromal reaction
Correct answer: C. Intact basement membrane with no stromal invasion
Explanation
The defining criterion that separates carcinoma in situ (CIS) from invasive carcinoma is the integrity of the basement membrane. In CIS, even high-grade cytological abnormalities and mitotic activity are confined above an intact basement membrane. Once tumor cells breach the basement membrane and enter the stroma, the lesion is classified as invasive carcinoma with metastatic potential. Lymphovascular invasion, desmoplasia, and tumor necrosis are features of invasive lesions.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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