Incidental coenurosis: larval cestode presenting as an axillary mass.

This article describes the occurrence of a coenurus, the encysted larval stage of a cestode of the genus Multiceps, within the axilla of a 40-year-old Nigerian woman. The patient had a history of intraductal carcinoma of the breast two years prior to the finding of an ipsilateral axillary mass. Pathologic evaluation of the biopsy specimen yielded the diagnosis of coenurosis. Only four other cases of human Multiceps infestation have been reported in the United States with fewer than 100 validated cases worldwide. Surgical removal of the larval parasite is the only known effective therapy.