Multiple nodular lesions by colonic metastatic malignant melanoma

A 52 years-old caucasian man was referred from another citizen hospital to our Surgery Department presenting very poor clinical conditions, severe anemia (RGC 3.02 × 106 μl−1 – normal value 4.2–5.6, Hb 6.7 g/dl – normal value 12–16), rectorrhagia. Colonoscopy identified multiple nodular lesions, small in size (0.3–0.8 cm), scattered in the rectum and the colon, with spherical shaped without depression or ulceration, dark brown–black pigmented with violaceous ring around the base. These lesions were isolated in the right colon and clustered in the left colon (1). One of the lesions was resected, by inject and cut mucosectomy: histologic (EE stain) and immunohistochemical (HMB 45) (2) examination showed nests of big size epithelioid cells atrophizing colonic mucosa. The EGD finding was negative. Standard chest X-ray examination showed multiple coin lesions of lungs, which were considered to be metastatic tumours. Bronchoscopy confirmed the presence of multiple nodular lesions that resembled those described in the colon. The patient died 2 days after hospitalization following a multiorgan neoplastic failure. Autopsy revealed multiple hepatic methastasis and a subungual lesion of left thumb that proved to be an acral lentiginous melanoma. Usually, colonic metastatic malignant melanoma (1–22%) presents itself with flat, black macular lesions or subpeduncolated lesions, with dark or reddish depression or ulceration [1], [2] and [3]. The endoscopic appearance of our case is unusual and can imitate a different kind of lesion (for example, a vascular lesion or a Kaposi).