Mucin-Containing Rectal Carcinomas: Overview of Unique Clinical and Imaging Features.

The purpose of this study is to review the unique clinical and imaging features of mucin-containing rectal carcinomas. Mucinous rectal carcinoma is an uncommon tumor subtype with a worse prognosis. At MRI, it is marked by T2-hyperintense extracellular mucin. Difficulty in distinguishing cellular from acellular mucin and persistent tumor bulk can cause errors at restaging. Signet ring cell carcinoma contains intracellular mucin. The classic imaging appearance is rectal linitis plastica. Both tumor subtypes have a unique metastatic pattern.