title: Morphologic clues and utility of fluorescence in situ hybridization for the diagnosis of nevoid melanoma.
abstract: BACKGROUND
  Nevoid melanomas include melanomas with a low power silhouette similar to melanocytic nevi. However, at higher power magnification, nevoid melanoma may have severe nuclear atypia and dermal mitoses.
  
  
  METHODS
  We performed a clinical, pathological and molecular study on a series of 58 examples of nevoid melanoma, excluding cases with spitzoid morphology.
  
  
  RESULTS
  We identified distinct morphologic patterns: 'classic' nevoid melanoma, superficial spreading melanomas with nevoid invasive melanoma, lentigo maligna with nevoid invasive melanoma and deep penetrating nevus-like nevoid melanoma. Fluorescence in situ hybridization (FISH) was positive in 74% of cases. Copy number gains in 8q24 were common in amelanotic nevoid melanoma. The median follow-up was 28 months (range 140). At last follow-up, 37 patients had no evidence of disease, 3 were alive with metastases and 6 died from metastatic melanoma. Of these six patients who died, four had a sentinel lymph node biopsy (SLNB) performed, which was negative in all four.
  
  
  CONCLUSIONS
  We describe distinct clues to the diagnosis of nevoid melanoma including occult intraepidermal atypia, and expansile nesting resulting in asymmetric silhouette or dermal papillae expansion. We also describe that nevoid melanoma have infrequent SLNB involvement in aggressive cases, and have frequent 8q24 gains rather than 9p21 deletions. Our results suggest that nevoid melanoma are distinct from spitzoid melanomas and should be distinguished.
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Oriol
authors.initials: O
authors.lastname: Yélamos
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Busam
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Lee
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Meldi Sholl
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Sapna M
authors.initials: SM
authors.lastname: Amin
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Merkel
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Roxana
authors.initials: R
authors.lastname: Obregon
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Joan
authors.initials: J
authors.lastname: Guitart
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Pedram
authors.initials: P
authors.lastname: Gerami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D000096142:Cutaneous Malignant Melanoma
keywords: 8q24; fluorescence in situ hybridization; melanoma; molecular diagnostics; nevoid melanoma