Pilar Cyst
Pronunciation: /ˈpaɪlər sɪst/
Benign cyst arising from hair follicle structures, commonly occurring on the scalp and often incorrectly termed 'sebaceous cyst' in documentation.
Full Definition
A pilar cyst, also known as a trichilemmal cyst, is a benign cyst that arises from the outer root sheath of hair follicles. These cysts most commonly occur on the scalp and contain keratinaceous material without a granular layer. Pilar cysts are frequently misidentified as 'sebaceous cysts' in clinical documentation, though true sebaceous cysts are rare. The cysts are usually asymptomatic but may become inflamed or infected, requiring surgical excision. Complete removal of the cyst wall is essential to prevent recurrence.
Usage
Usage note: Preferred over 'sebaceous cyst' which is often incorrectly applied to these lesions.
In Context
- "The scalp lesion was diagnosed as a pilar cyst and excised with its intact capsule." — Operative report
- "Histopathology confirmed a pilar cyst with characteristic trichilemmal keratinization pattern." — Pathology report