title: Metastatic gastric melanoma: a challenging diagnosis.
abstract: BACKGROUND
  The stomach is regarded as a rare site for metastasis. When a gastric mass is observed macroscopically, the presumed diagnosis is usually a primary gastric carcinoma. However, the stomach may be involved in metastatic malignant melanoma. Besides a possible macroscopical misdiagnosis, metastatic gastric melanoma may also be misdiagnosed microscopically as adenocarcinoma due to its protean histological characteristics. These features make metastatic gastric melanoma a challenging diagnosis in some cases.
  
  
  METHODS
  We report a patient with metastatic gastric melanoma referred to us with an initial macroscopic and histopathological diagnosis of primary gastric adenocarcinoma. He was diagnosed as having metastatic gastric melanoma by further examination because of the peculiar metastatic involvement and normal gastrointestinal tumor marker levels.
  
  
  CONCLUSIONS
  The stomach may be involved in melanoma and melanoma metastasis to the stomach is a diagnosis that should be taken into account while evaluating any gastric mass lesion. It is likely to be encountered more commonly nowadays due to the significant increase in the melanoma incidence. A history of melanoma, an atypical metastatic pattern, and normal gastrointestinal tumor marker levels may contribute to its diagnosis.
authors.affiliation: Department of Internal Medicine, Istanbul University, Capa/Istanbul, Turkey. gbahatozturk@yahoo.com
authors.forename: Gulistan
authors.initials: G
authors.lastname: Bahat
authors.forename: Bulent
authors.initials: B
authors.lastname: Saka
authors.forename: Yasar
authors.initials: Y
authors.lastname: Colak
authors.forename: Cemil
authors.initials: C
authors.lastname: Tascioglu
authors.forename: Mine
authors.initials: M
authors.lastname: Gulluoglu
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000556:secondary*; D008875:Middle Aged; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000556:secondary*