title: Where pigmented pilomatricoma and melanocytic matricoma collide.
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.
authors.affiliation: Department of Dermatology, Medical University of Graz, Austria.
authors.forename: Ben
authors.initials: B
authors.lastname: Tallon
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cerroni
mesh_terms: D000293:Adolescent; D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D049109:Cell Proliferation; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006201:Hair Diseases / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D008297:Male; D008544:Melanocytes / Q000737:chemistry / Q000473:pathology*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D018296:Pilomatrixoma / Q000737:chemistry / Q000473:pathology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D009418:S100 Proteins / Q000032:analysis; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*; D012880:Skin Pigmentation
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C522981:Melan-A 51-73 peptide; D009363:Neoplasm Proteins; D009418:S100 Proteins