Synchronous primary malignancies of the appendix and ovary causing carcinomatosis in one patient.

Associated tumors of the ovary and the appendix are commonly found in cases of pseudomyxoma peritonei (PP); the origin of these tumors are a continually debated topic. Outside of the setting of PP, this finding is exceedingly rare and there are no documented reports of two primary processes causing carcinomatosis in the absence of PP. Here, we present a patient who underwent cytoreductive surgery for peritoneal carcinomatosis presumptively secondary to ovarian carcinoma and who on pathological examination was found to have synchronous primary malignant processes of both the appendix and the ovary. This represents the first documented case of carcinomatosis resulting from two separate malignant processes in the absence of PP.