CMID Practice Test 2026 - Free CMID Practice Questions and Study Guide

In immunohistochemistry, the result is described by listing the markers that show positivity. If a sample is positive for CK7 and CDX2, the description matches exactly the two markers involved: CK7, CDX2. CK7 is a cytokeratin commonly expressed in many epithelial tumors, while CDX2 is a marker of intestinal differentiation. The other options describe different marker profiles (for example, TTF-1 with PAX8 suggests a different lineage, Melan-A points to melanoma, and PAX8 alone indicates another lineage), none of which match both CK7 and CDX2 positivity.