Mucinous cancer of the appendix: challenges in diagnosis and treatment.

The authors report and discuss a case of a mucinous carcinoma of the appendix, a rare entity with a distinct natural history that poses diagnostic and therapeutic challenges. Mucinous peritoneal carcinomatosis is most commonly associated with primary tumors of the appendix and colon. Typically, spread remains confined to the abdominal cavity. Imaging assessment of these mucinous lesions is difficult, while tumor markers (CEA and CA19.9) may be surrogates for extent of disease. Treatment consists of surgical debulking, sometimes coupled with intraperitoneal drug delivery, but recurrence is universal. New treatment approaches are needed. Mucin genes are regulated in part by epidermal growth factor receptor signaling. Therefore, we initiated a phase II study of cetuximab for mucinous peritoneal carcinomatosis, that was part of this patient's treatment.