PRIMARY SMALL BOWEL MELANOMA: RX, CT AND COLOR –DOPPLER US FINDINGS

Purpose: We present a rare case of primary melanoma originating in the small bowel mucosa and report the imaging findings at CT, Rx, color-doppler US and open surgery.

Methods and Materials: Case report: Female, 49 years old, admitted at our Institution because of asthenia, epigastric pain, chronic anaemia and loss of weight. At clinical examination, heart, chest and abdomen were normal. All tumor markers were negative. Gastroscopy showed normal esophagus, stomach and duodenum. Abdominal Color-Doppler-Ultrasound (CD-US) showed a hypervascular, hypoechoic mass (diameter: 7×6 x 5cm) in the left upper abdominal quadrant next to the midline with a satellite hypoechoic nodule (diameter: 19mm). The diagnosis of carcinoma of the transverse colon with lymphnodal metastasis was suggested. Howewer, colonoscopy showed normal colonic mucosa. Abdominal enhanced CT showed a jejunal mass with central contrast enhancement in the arterial phase. The diagnosis of lymphoma or leiomioma was suggested. Double-contrast Xray of the small bowel showed: normal duodenum, stretched and distended jejunal loops proximal to a narrowed jejunal lumen caused by a intramural mass. The distal jejunum and ileum were normal.

Results: Surgery showed a polypoid mass (diameter: 7,5cm) and 3 enlarged mesenteric lymphnodes. Pathologic examination showed: “epithelioid tumor with intracellular brown pigmentation infiltrating lymphatic vessels. At immunochemistry, marked positivity for S100 and focal positivity for HMB45 antigens. 1 lymphnode positive for malignancy “. Conclusions: Melanoma of the small bowel.

Anamnesis of the patient was negative for any previous cutaneous or mucosal surgery. The clinical inspection and a 4 months follow-up failed to show any suspicious cutaneous lesion.

Conclusions: prymary jejunal melanoma is a reliable diagnosis in this case. Although CD-US can be very useful as first approach examination, only CT and X-ray could exactly identify the site were the tumor originated. Howewer, only US detected metastatic mesenteric lymphnode before surgical excision.