Multicentric calcified trichilemmal cysts with alopecia universalis affecting siblings

Abstract

Trichilemmal cyst, also known as "pilar cyst," is a benign cyst containing keratin and its breakdown products with a wall resembling external root sheath of hair. It occurs mostly in females as a solitary firm nodule over scalp. Occurrence of multiple trichilemmal cysts in areas other than scalp is extremely rare. We are reporting a case of a 40-years-old female who presented with multiple calcified trichilemmal cysts in multicentric distribution associated with alopecia universalis. Similar complaints were present in elder sister of the patient, indicating a genetic background. Multicentric distribution of trichilemmal cysts, calcification, familial occurrence, and association with alopecia universalis seen in our case are all rare and intriguing features.

Trichilemmal Cyst: Clinical and Sonographic Features

“…In this study, 50 patients with TCs had female predominance and a mean patient age was 43.4 years, in agreement with previous published data . The most frequently observed site of lesion was the subcutaneous layer of the scalp, which was also consistent with previous studies.…”

Distinguishing a Trichilemmal Cyst From a Pilomatricoma With Ultrasound

“…Both trichilemmal cysts and pilomatricomas had a slight female predominance, which was consistent with previous reports . Sex ratios in both groups were fairly equal.…”

“…Sex ratios in both groups were fairly equal. Trichilemmal cysts occurred in individuals older than 15 years with pilomatricomas, and mean patient ages for both groups were in agreement with previously published data . However, other literature indicates that pilomatricomas present primarily in the first and second decades of life .…”

“…A possible explanation may be that most children with pilomatricomas choose to visit children’s hospitals instead of our hospital. Trichilemmal cysts were located mainly in the scalp, which was consistent with previous reports . Pilomatricomas occurred predominately in the extremities and neck, whereas the most common sites in previous studies were the head and neck .…”

Solitary calcified trichilemmal cyst on forearm

“…Few cases have been reported to occur on finger pulp, vulva, eyelid, intraoral area, extensor aspect of forearm, and gluteal region. [34]…”