Case 34

A 80-year-old male with a 4.5 cm lung nodule, a biopsy was done.

1. What's the favored morphology catergory?

   A: primary lung non-mucinous adenocarcinoma

   B: mucoepidermoid carcinoma

   C: metastatic adenocarcinoma, favor GYN origin

   D: metastatic adenocarcinoma, favor lower GI origin

Answer

It's a case of metastatic colonic adenocarcinoma, in real life history will be important but this is the classic morphology of metastatic colon adenocarcinoma. Histologic features of glandular architecture in tumors include the formation of irregular, cribriform, or back-to-back glands lined by columnar epithelial cells with varying degrees of nuclear atypia and mitotic activity. Extracellular mucin is commonly observed, particularly in mucinous adenocarcinomas, and signet-ring cells with intracellular mucin displacing the nucleus may also be present. Nuclear features include enlarged, hyperchromatic nuclei, nuclear pseudostratification, and prominent nucleoli, especially in more aggressive tumors. A desmoplastic stromal reaction, characterized by dense fibrotic stroma surrounding malignant glands, is frequently noted. Additionally, central "dirty necrosis," marked by sloughed cells and debris within glandular lumina, is a common finding.

Case credit: UCSD Pathology

Author: Wangpan Jackson Shi, MD