Mucinous adenocarcinoma of the appendix associated with ovarian tumors and pseudomyxoma peritonei. The difficulty in differential diagnosis

Abstract Mucinous adenocarcinoma of the appendix is rare. If there is a concomitant ovarian tumor to determine the primary might be difficult. Histological features are not always determinant, but there are some macroscopic findings that may suggest an origin in the appendix. We report a case of synchronous tumors in appendix and ovaries with pseudomyxoma peritonei. The patient presented with mass sensation in the right lower quadrant, asthenia, anorexia and weight loss. Abdominal ultrasound and CT scan showed a tumor involving cecum, appendix, terminal ileum and pelvis. Findings on colonoscopy and biopsies were inconclusive. At laparotomy, the tumor compressed appendix, cecum and ascendant colon, terminal ileum, ovaries and peritoneum. Histopathological analysis demonstrated a well-differentiated mucinous adenocarcinoma of appendiceal origin with metastasis in ovaries and peritoneum (pseudomyxoma peritonei).