title: Hair cortex comedo: a series of 34 cases.
abstract: Hair cortex comedo was described originally in an article detailing 2 cases of a comedo-like clinical lesion that was histologically a keratinous plug with cornification similar to the cortex of the hair shaft. We have collected retro- and prospectively a series of 34 cases of hair cortex comedo. In our series, there was a slight female predominance (Male:Female of 1:1.4), and the mean patient age was 28.8 years. All lesions were solitary, distributed mainly on the head and neck or trunk, and were described clinically as a blue subcutaneous papule or nodule with "cyst" as the most common clinical differential diagnosis. Histologic examination showed a solitary, vertically oriented, uniformly sized oval nodule of compact laminated corneocytes sitting in a patulous invagination lined by epithelium similar to the infundibulum, isthmus, or combinations of them; rarely matrical epithelium was identified. Entrapped melanin (30/34 cases), shadow cells (16/34 cases), and calcification (12/34 cases) were identified commonly. Remnants of a surrounding follicle were noted in 15 cases, with infundibular epithelium in 9 of the cases, isthmic epithelium in 3, and matrical or supramatrical epithelium (or both) in 3. There was an associated dense granulomatous infiltrate in the majority of the cases (25/34). Although hair cortex comedo was thought originally to be a variant of dilated pore of Winer, we believe that these distinctive lesions, which are characterized histopathologically by a uniformly sized vertically oriented dermal plug of laminated corneocytes with entrapped melanin and surrounding granulomatous inflammation, are likely derived from matrical or supramatrical cells (or both).
authors.affiliation: WCP Laboratories Inc., St. Louis, MO 63043, USA. sorahnwalsh@aol.com
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Walsh
authors.forename: Daniel J Santa
authors.initials: DJ
authors.lastname: Cruz
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hurt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006099:Granuloma / Q000473:pathology; D006201:Hair Diseases / Q000378:metabolism / Q000473:pathology*; D018859:Hair Follicle / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D007633:Keratins / Q000032:analysis; D008297:Male; D008543:Melanins / Q000032:analysis; D008875:Middle Aged; D008923:Missouri; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D008543:Melanins; D007633:Keratins