title: Morphological spectrum of pilar cysts.
abstract: BACKGROUND
  Cysts of the skin are one of the commonly excised specimens in the surgical outpatient department. A majority of them being clinically diagnosed as sebaceous cysts, their true nature is only discernible on histopathological examination. Closer examination of the type of keratinization involved will throw light into the exact nature of the cyst. Trichilemmal or Pilar cyst is one such entity, which presents in both a non-neoplastic and neoplastic form.
  
  
  OBJECTIVE
  The present retrospective observational study was undertaken to find out the incidence of these cysts in surgical pathology practice in a rural hospital and to enlist the various morphological forms that these cysts may take.
  
  
  METHODS
  The histopathology files were reviewed for a period of 6 years for cases coded as pilar cyst.
  
  
  RESULTS
  A total of eight cases (5.75%) were identified, which showed features of trichilemmal differentiation. A single case each of proliferating trichilemmal cyst and malignant proliferating trichilemmal tumors were noted. Most of the cases were seen among females on the scalp.
  
  
  CONCLUSIONS
  Trichilemmal tumor is an uncommon histopathological entity. Many of these lesions may be mistakenly diagnosed due to lack of recognition of the unique type of keratinization.
authors: Department of Pathology, P.E.S Institute of Medical Sciences and Research, Kuppam, Andhra Pradesh, India.
authors: Anikode Subramanian
authors: AS
authors: Ramaswamy
authors: Hanumanthappa Krishnappa
authors: HK
authors: Manjunatha
authors: Bylappa
authors: B
authors: Sunilkumar
authors: Sulkunte Palaksha
authors: SP
authors: Arunkumar
keywords: Malignant pilar tumor; Pilarcyst; Proliferating pilar tumor; Proliferating trichilemmal cyst
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