title: Pancreatic PEComa: a case report with ultrastructural localization of HMB-45 within melanosomes.
abstract: PEComas (perivascular epithelioid cell tumors) represent a group of mesenchymal neoplasms showing characteristic morphologic, immunohistochemical, ultrastructural, and genetic features. These neoplasms are usually considered benign, being often well circumscribed by a thin capsule and showing scarce atypia. However, in some cases, they show local invasion and multiple metastases and cause the patient's death. PEComas have been found in many locations, but only 7 cases have been described in the pancreas to date. Here, the authors report an additional case of this rare neoplasm and demonstrate the HMB-45 immunoreactivity of melanosomes or premelanosomes at the ultrastructural level.
authors.affiliation: Department of Pathology, Ospedale di Circolo, Varese, Italy. giovanna.finzi@ospedale.varese.it
authors.forename: Giovanna
authors.initials: G
authors.lastname: Finzi
authors.forename: Donata
authors.initials: D
authors.lastname: Micello
authors.forename: Giorgio
authors.initials: G
authors.lastname: Wizemann
authors.forename: Fausto
authors.initials: F
authors.lastname: Sessa
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
mesh_terms: D014408:Biomarkers, Tumor; D015622:Epithelioid Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D058950:Melanoma-Specific Antigens / Q000378:metabolism*; D020460:Melanosomes / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D054973:Perivascular Epithelioid Cell Neoplasms / Q000378:metabolism* / Q000473:pathology; D016896:Treatment Outcome; D058951:gp100 Melanoma Antigen
chemical_list: D014408:Biomarkers, Tumor; D058950:Melanoma-Specific Antigens; C548637:PMEL protein, human; D058951:gp100 Melanoma Antigen