title: Melanotic PEComa of the Sinonasal Mucosa With NONO-TFE3 Fusion: An Elusive Mimic of Sinonasal Melanoma.
abstract: Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal tumors with features of both smooth muscle and melanocytic differentiation, with or without true melanin pigment. The highly variable morphology of PEComas results in a broad differential diagnosis that is also dependent on anatomic site. A subset demonstrates rearrangements involving the TFE3 (Xp11) locus, which can be used in diagnostically difficult cases. Here we describe a case of a melanotic PEComa with NONO-TFE3 fusion occurring in the sinonasal mucosa, as demonstrated by both next-generation sequencing and molecular cytogenetic studies. This case is the first of its kind in the literature and only the second documented PEComa harboring a NONO-TFE3 rearrangement. In light of unequivocal molecular ancillary studies, this case illustrates that PEComa must enter the differential for pigmented lesions of the sinonasal mucosa, where malignant melanoma would be much more likely to occur.
authors.affiliation: *Department of Pathology, University of Chicago Medicine §Chicago Otolaryngology Associates, Chicago ‡Dermatopathology, Midwest Diagnostic Pathology, Park Ridge, IL †Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI ∥Department of Pathology/Microbiology, Pediatrics, and Orthopaedic Surgery, 983135 Nebraska Medical Center, University of Nebraska, Omaha, NE.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: McGregor
authors.forename: Mir B
authors.initials: MB
authors.lastname: Alikhan
authors.forename: Rahel A
authors.initials: RA
authors.lastname: John
authors.forename: Howard
authors.initials: H
authors.lastname: Kotler
authors.forename: Julia A
authors.initials: JA
authors.lastname: Bridge
authors.forename: Ibro
authors.initials: I
authors.lastname: Mujacic
authors.forename: Sabah
authors.initials: S
authors.lastname: Kadri
authors.forename: Jeremy
authors.initials: J
authors.lastname: Segal
authors.forename: Thomas
authors.initials: T
authors.lastname: Krausz
mesh_terms: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics*; D001706:Biopsy; D004268:DNA-Binding Proteins; D003937:Diagnosis, Differential; D005260:Female; D050939:Gene Fusion; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008543:Melanins / Q000032:analysis*; D008545:Melanoma / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry* / Q000473:pathology; D009669:Nose Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D034521:Nuclear Matrix-Associated Proteins / Q000235:genetics*; D050810:Octamer Transcription Factors / Q000235:genetics*; D054973:Perivascular Epithelioid Cell Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D011237:Predictive Value of Tests; D016601:RNA-Binding Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D008543:Melanins; C083214:NONO protein, human; D034521:Nuclear Matrix-Associated Proteins; D050810:Octamer Transcription Factors; D016601:RNA-Binding Proteins; C069203:TFE3 protein, human