Where pigmented pilomatricoma and melanocytic matricoma collide

Am J Dermatopathol. 2010 Dec;32(8):769-73. doi: 10.1097/DAD.0b013e3181d88d15.

Abstract

Pilomatricoma and matricoma are 2 benign epithelial tumours derived from the hair matrix. Although containing the same constituent cells, the silhouette differs, with matricoma comprised of a predominantly solid basaloid proliferation with only focal areas of shadow cell formation. The recently described melanocytic matricoma appears to be a similar tumor with numerous interspersed melanocytes. We studied retrospectively 28 pilomatricomas and 2 pilomatrical carcinomas to check for the presence of melanocytes using immunohistochemical staining to S-100 and Melan-A. Three cases of pilomatricoma with prominent melanocytic hyperplasia were detected, confirming this as a rare (11%) occurrence. Both cases of pilomatrical carcinoma were negative. Comparison of these tumors with a further case of melanocytic matricoma led to a critical analysis of the relationship of pilomatricoma, matricoma, and melanocytic matricoma. Although further comparison is required, we suggest that melanocytic matricoma may be simply a pigmented melanocytic variant of matricoma, in the same way as we accept pigmented pilomatricoma as a variant of pilomatricoma. In this report we provide features that may be used to discriminate matricoma and pilomatricoma and their pigmented variants.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Aged
  • Antigens, Neoplasm / analysis
  • Biomarkers, Tumor / analysis
  • Cell Proliferation
  • Child
  • Diagnosis, Differential
  • Female
  • Hair Diseases / metabolism
  • Hair Diseases / pathology*
  • Humans
  • Hyperplasia
  • Immunohistochemistry
  • Male
  • Melanocytes / chemistry
  • Melanocytes / pathology*
  • Middle Aged
  • Neoplasm Proteins / analysis
  • Pilomatrixoma / chemistry
  • Pilomatrixoma / pathology*
  • Predictive Value of Tests
  • Retrospective Studies
  • S100 Proteins / analysis
  • Skin Neoplasms / chemistry
  • Skin Neoplasms / pathology*
  • Skin Pigmentation*

Substances

  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • Melan-A 51-73 peptide
  • Neoplasm Proteins
  • S100 Proteins