RESUMEN
Primary mucinous adenocarcinoma is a rare malignancy of the anus (3% of anal cancers), the pathogenesis of which is better understood by immunohistochemistry. We reviewed cases of primary mucinous adenocarcinoma of the anus from 2000 to 2009 in the Hepatogastroenterology Department of the University Hospital Centre of Marrakech. Three cases were identified who were males with the mean age of 68years, and presented with a chronic anal fistula. Two cases had anal pain. Clinical examination revealed multiple fistulae in two cases with a secretion simulating 'cooked grains of tapioca'. Diagnosis was confirmed by histopathology and immunohistochemical profile (CK7 positive/CK20 negative). Imaging revealed a retro-rectal collection with thickening of the anal wall without metastasis (two cases). One patient underwent abdominoperinal resection without recurrence.