A case is reported of a patient with a benign appendiceal neoplasm presenting incidentally with mucin in an inguinal hernial sac. Only one such case of a benign tumour, and one such case of cystadenocarcinoma, have previously been reported. In neither of these cases was laparoscopy used in diagnosis or staging of the disease. We review the management of such cases in light of recent proposed changes to pathological classification.