title: Primary dermal melanoma: a unique subtype of melanoma to be distinguished from cutaneous metastatic melanoma: a clinical, histologic, and gene expression-profiling study.
abstract: BACKGROUND
  Primary dermal melanoma (PDM) is a subtype of melanoma confined to the dermis that may be morphologically impossible to distinguish from cutaneous metastatic melanoma (CMM).
  
  
  OBJECTIVE
  We sought to better characterize PDM by describing the clinical, histologic, and molecular features of 49 cases of PDM and determine whether a gene expression-profiling test could help distinguish PDM from CMM.
  
  
  METHODS
  We describe 49 cases of PDM and determined whether any clinical or histopathologic features had a statistically significant relationship with outcome. Secondly, we performed a melanoma gene expression-profiling test on a subset of the PDM and CMM cases.
  
  
  RESULTS
  Overall recurrence was infrequent and seen in 9 of 49 cases. Six patients had locoregional recurrences and 3 patients had distant metastasis. None of the clinical or histologic parameters showed a statistically significant relationship with recurrence. There was a statistically significant association of a class I signature by DecisionDx-Melanoma assay (Castle Biosciences Inc, Friendswood, TX) for PDM whereas CMM were more frequently class II (P value = .023).
  
  
  CONCLUSIONS
  The mean follow-up time was 26 months.
  
  
  CONCLUSIONS
  Most conventional staging parameters used for prognosis in cutaneous melanoma have limited applicability to PDM. The melanoma prognostic assay may be a useful tool for distinguishing PDM from CMM.
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Michael
authors.initials: M
authors.lastname: Sidiropoulos
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Roxana
authors.initials: R
authors.lastname: Obregon
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Cooper
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Lauren Meldi
authors.initials: LM
authors.lastname: Sholl
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Joan
authors.initials: J
authors.lastname: Guitart
authors.affiliation: Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Electronic address: pgerami@nmff.org.
authors.forename: Pedram
authors.initials: P
authors.lastname: Gerami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008545:Melanoma / Q000145:classification / Q000235:genetics* / Q000556:secondary*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D012878:Skin Neoplasms / Q000145:classification / Q000235:genetics* / Q000473:pathology*; D059467:Transcriptome; D000096142:Cutaneous Malignant Melanoma
keywords: American Joint Committee on Cancer; cutaneous metastatic melanoma; fluorescence in situ hybridization; gene expression profile; melanoma; primary dermal melanoma