title: Differential diagnosis of non-epithelial tumors of the pancreas: malignant non-epithelial pancreatic tumor with focal pigmentation.
abstract: Non-epithelial tumors only rarely affect the pancreas. In this report, we describe a malignant non-epithelial tumor with combined characteristics of malignant peripheral nerve sheath tumor (MPNST) and malignant melanoma. To more closely define the differential diagnosis of MPNST with focal pigmentation versus metastatic melanoma resembling MPNST, the tumor was investigated using histomorphology, immunohistochemistry, electron microscopy, and comparative genomic hybridization. As a result, from these analyses and from clinical findings, the diagnosis of a pancreatic MPNST with focal pigmentation was favored. However, the diagnosis of a malignant melanoma or a composite tumor could not be definitely ruled out, due to the considerable morphological and genotypical overlap between both entities, which can be explained by the close histogenetic relationship between both tumor entities.
authors.affiliation: Institute of Pathology, University of Heidelberg, Germany. frank_bergmann@med.uni-heidelberg.de
authors.forename: Frank
authors.initials: F
authors.lastname: Bergmann
authors.forename: Thilo
authors.initials: T
authors.lastname: Hackert
authors.forename: Gunhild
authors.initials: G
authors.lastname: Mechtersheimer
authors.forename: Roland
authors.initials: R
authors.lastname: Penzel
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bläker
authors.forename: Irina
authors.initials: I
authors.lastname: Berger
authors.forename: Irene
authors.initials: I
authors.lastname: Esposito
authors.forename: Markus W
authors.initials: MW
authors.lastname: Büchler
authors.forename: Herwart F
authors.initials: HF
authors.lastname: Otto
mesh_terms: D001932:Brain Neoplasms / Q000556:secondary; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000556:secondary / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000473:pathology* / Q000556:secondary / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D010858:Pigmentation