title: Orbital meningeal melanocytoma: Histological, immunohistochemical and molecular characterization of a case and review of the literature.
abstract: OBJECTIVE
  We provide morphological, immunohistochemical and molecular characterization of the 3rd "intermediate-grade" orbital meningeal melanocytoma, testing for the first time Vysis Melanoma FISH Probe Kit. We reviewed the literature in order to discuss the main differential diagnoses and to provide a better molecular description of these unusual tumors of difficult diagnosis and controversial management.
  
  
  METHODS
  Histochemical stains (Haematoxylin and Eosin, Perls, reticulin), immunohistochemistry (HMB45, p16, Melan-A, S100, EMA, Ki67, CD68), polymerase chain reaction amplification and sequence analysis (BRAF, exon 15; NRAS exons 2 and 3; c-KIT, exons 11, 13, 17, 18; GNAQ, exons 4 and 5; GNA11, exons 4 and 5) and fluorescent in situ hybridization (RREB1, 6p25; MYB, 6q23; CCND1, 11q13; CEP 6, 6p11.1-q11.1) were performed on paraffin-embedded, formalin-fixed material.
  
  
  RESULTS
  Histological diagnosis of "intermediate-grade" melanocytoma was supported by zonal necrosis and increased Ki67-index (12%). Immunophenotype: HMB45+(strong, >75%), Melan-A+(strong, >75%), p16+(∼20%), S100 -/+ (<5%), EMA -/+ (<5%), CD68 - (positive histiocytes). No gene mutations nor copy-number alterations were identified. The patient was asymptomatic and disease-free 3 years after total surgical excision.
  
  
  CONCLUSIONS
  Adequate sampling and accurate immunohistochemical characterization are important for a correct diagnosis. Molecular analysis could provide important additional information (especially for "intermediate-grade" tumors), but further data are needed.
authors: Department of Health Science, School of Medicine, "Maggiore della Carità" Hospital, University of Eastern Piedmont "Amedeo Avogadro", via Solaroli 17, 28100, Novara, Italy. Electronic address: andreapalicelli@hotmail.it.
authors: Andrea
authors: A
authors: Palicelli
authors: Department of Health Science, School of Medicine, "Maggiore della Carità" Hospital, University of Eastern Piedmont "Amedeo Avogadro", via Solaroli 17, 28100, Novara, Italy. Electronic address: mariagiuliadisanto@gmail.com.
authors: Maria Giulia
authors: MG
authors: Disanto
authors: Neurosurgery Unit, "Maggiore della Carità" Hospital, Corso Mazzini 18, 28100, Novara, Italy.
authors: Gabriele
authors: G
authors: Panzarasa
authors: Department of Pathology, "Maggiore della Carità" Hospital, University of Eastern Piedmont "Amedeo Avogadro", Corso Mazzini 18, 28100, Novara, Italy.
authors: Claudia
authors: C
authors: Veggiani
authors: Diagnostic Radiology Unit, "SS Trinità" Hospital, Viale Zoppis 10, 28021, Borgomanero, Italy.
authors: Gabriella
authors: G
authors: Galizia
authors: Diagnostic Radiology Unit, "SS Trinità" Hospital, Viale Zoppis 10, 28021, Borgomanero, Italy.
authors: Stefano
authors: S
authors: Dal Cin
authors: Laboratory of Oncologic and Transplantation Molecular Pathology, Department of Pathology, S.Orsola-Malpighi Hospital, University of Bologna, Via Pietro Albertoni, 15,40138, Bologna, Italy.
authors: Elisa
authors: E
authors: Gruppioni
authors: Department of Health Science, School of Medicine, "Maggiore della Carità" Hospital, University of Eastern Piedmont "Amedeo Avogadro", via Solaroli 17, 28100, Novara, Italy; Department of Pathology, "Maggiore della Carità" Hospital, University of Eastern Piedmont "Amedeo Avogadro", Corso Mazzini 18, 28100, Novara, Italy. Electronic address: renzo.boldorini@med.unipmn.it.
authors: Renzo
authors: R
authors: Boldorini
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D005134:Eye Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor
keywords: FISH; Melanocytoma; Orbit; Orbital; PCR