Seromucinous borderline tumor of the peritoneum

Abdominal wall tumors are sometimes diagnosed as metastases of ovarian cancer, however, primary peritoneal tumors should be taken into consideration in the final diagnosis. Primary serous borderline tumor of the peritoneum is an uncommon disease difficult to diagnose, its treatment may be not clear due to the lack of cases in literature. A 28-year-old female patient was admitted in our Emergency Department with a pulpable abdominal wall lump, abdominal pain localized in the right lower abdomen, with fever (38°C), and signs of bowel obstruction. After an abdominal US and a MRI that showed a lump (95mm x 92mm x 86mm) in the right lower abdomen she undergone right colectomy. On histology examination, the excised specimen revealed characteristics of serous borderline tumor of the peritoneum with gastrointestinal cells. This is the fourth described case of solitary primary seromucinous peritoneal tumor located in the abdominal wall. This condition should be included in the differential diagnosis of a probable metastatic ovarian carcinoma, as both present similar histologic characteristics.