Malignant melanoma with mesenteric metastasis causing an intrapelvic abscess: report of a case.

We present herein the case of a 66-year-old woman with disseminated malignant melanoma in whom a metastasis in the ileal mesentery ruptured into the peritoneal cavity causing an acute abdomen. The patient suddenly developed lower abdominal pain and a computed tomography (CT) scan of the pelvis confirmed the presence of an intrapelvic abscess. At emergency laparotomy, a 10 x 10 cm ruptured metastatic melanoma was found in the ileal mesentery, which demonstrated no communication with the ileum itself. To our knowledge, no other case of an acute abdomen being caused by the rupture of mesenteric metastatic melanoma lacking any communication with the bowel lumen has ever been reported.