title: Morphologically and immunohistochemically undifferentiated gastric neoplasia in a patient with multiple metastatic malignant melanomas: a case report.
abstract: BACKGROUND
  Malignant melanoma is a neoplasia which frequently involves the gastrointestinal tract (GIT). GIT metastases are difficult to diagnose because they often recur many years after treatment of the primary cutaneous lesion and also manifest clinically at an advanced stage of the neoplasia. Furthermore, GIT metastases can appear in various morphological forms, and therefore immunohistochemistry is often useful in distinguishing between a malignant melanoma and other malignancies.
  
  
  METHODS
  We report the case of a 60-year-old man with a multiple metastatic melanoma who underwent an upper endoscopy to clarify the possible involvement of the gastric wall with a mass localized in the upper abdomen involving the pancreas and various lymph nodes, which was previously described with computed tomography. Clinically, the patient reported a progressive loss of appetite, nausea and vomiting. The upper endoscopy and histological examination revealed a gastric location of an undifferentiated neoplasm with an absence of immunohistochemical characteristics referable to the skin malignant melanoma that was removed previously.
  
  
  CONCLUSIONS
  The present case report shows the difficulty in diagnosing a metastatic melanoma in the GIT and therefore, it seems worthwhile to consider metastatic malignant melanoma in the differential diagnosis of undifferentiated neoplasia.
authors.affiliation: Gastroenterology Unit, Department of Clinical Sciences, Policlinico Umberto I, University 'La Sapienza', Rome, Italy. federicoalghisi@libero.it
authors.forename: Federico
authors.initials: F
authors.lastname: Alghisi
authors.forename: Pietro
authors.initials: P
authors.lastname: Crispino
authors.forename: Andrea
authors.initials: A
authors.lastname: Cocco
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Richetta
authors.forename: Francesco
authors.initials: F
authors.lastname: Nardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Paoluzi
authors.forename: Danilo
authors.initials: D
authors.lastname: Badiali