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Updated: Aug 1, 2026

A 3D Organotypic Melanoma Spheroid Skin Model
Published on: May 18, 2018
Primary anal melanoma associated with melanosis of the upper gastrointestinal tract
1Gastrointestinal Endoscopy Unit, Hospital Porto Alegre, Brazil. Horowitz@vortex.ufrgs.br
Abstract:
A 49-year old severely ill man, with no digestive complaints, was admitted to our hospital. Abdominal ultrasound was suggestive of hepatic metastases. Endoscopy revealed multiple, flat and polypoid, pigmented lesions in the esophagus, stomach and duodenum. Biopsy showed only melanotic pigment, without malignant cells. A bone marrow biopsy confirmed the diagnosis of metastatic melanoma. A flexible rectosigmoidoscopy revealed a dark polypoid lesion. Histological analysis confirmed the diagnosis of anal melanoma. These findings demonstrate that melanosis can occur concomitantly with anal melanoma and in different segments of the upper gastrointestinal tract.
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