A histomorphological study of trichilemmal cysts: a rural hospital experience

Abstract

Introduction: Among Cystic lesions of skin the most common clinical diagnosis is sebaceous cyst. Cystic lesions of the skin are most commonly encountered in surgical practice. Among these cyst lesions Trichilemmal cysts are very rare and these cysts are benign non-neoplastic lesions. pilar theory says that the follicular isthmus of the external root sheath of the hair follicle as the exact origin of these pilar cysts and suggested the name trichilemmal cyst.

Objectives: The present study was undertaken to study and find out the incidence of Trichilemmal cysts in a rural area and to study the various histomorphological forms of Trichilemmal cysts which were encountered in surgical pathology in and around Konaseema region at rural hospital over a period of three years.

Methods: This was a three years retrospective study done between January 2012 to December 2014, the data retrieved from histopathology files. The paraffin embedded and H;E stained slides were removed from the files. A few old slides were re-stained again with hematoxylin and eosin, these slides studied under microscope and histomorphological features were noted.

Result: Out of 135 skin lesions which were retrieved, seven cases (5.18%) showed Trichilemmal differentiation. Out of these seven cases one case showed the features of proliferating trichilemmal cyst and other one more case showed features of malignant proliferating trichilemmal cyst. Conclusion: Extensive histomorphological examination is must for cysts showing the trichilemmal type of keratinisation, because many of these lesions may be mistakenly diagnosed as squamous cell carcinomas.