Signet-Ring Cell Adenocarcinoma of Sinonasal Tract: An Immunohistochemical Study of the Mucins Profile

Abstract

Abstract Context.—Adenocarcinomas of the sinonasal tract are classified into 4 categories: salivary-type, intestinal-type, nonintestinal-type, and metastatic. Signet-ring cell carcinoma is the rarest form of intestinal-type adenocarcinoma. Only isolated cases have been reported in the literature. Objective.—To evaluate clinical attributes, morphology, and immunohistochemistry in signet-ring cell carcinoma of the sinonasal tract. Design.—Seventy-three cases of primary sinonasal adenocarcinomas were retrieved from the files. Only 5 signet-ring cell adenocarcinomas (tumors composed of more than 90% signet-ring cells) were identified. In all cases, clinical data and histologic slides were available and were reviewed. Consecutive tissue sections were immunostained with monoclonal antibodies against MUC2, MUC5AC, MUC5B, MUC6, p53 protein, and MIB-1. Results.—Four of our 5 patients were woodworkers. They were treated by surgical excision and radiotherapy. Patient follow-up ranged from 11 to 84 months. Three patients presented an unfavorable evolution and died of metastatic spread. Microscopically, the tumors produced abundant mucin deposits, which accumulated in large extracellular pools. Tumor cells were predominantly signet-ring cells floating in the pools of mucin. The mucins profile was MUC2+, MUC5AC+, MUC5B+, and MUC6−. Eighty percent of cells were immunostained by p53 protein antibody and 60% cells with MIB-1 antibody. Conclusions.—The mucin profile is similar to the profile described in digestive tract adenocarcinoma. It is not useful to differentiate between metastatic adenocarcinoma and primary intestinal-type sinonasal adenocarcinoma. Clinical data and immunochemistry with p53 protein and MIB-1 confirm that sinonasal signet-ring cell carcinoma is a high-grade and aggressive tumor.