Pilar cyst on the dorsum of hand

Abstract

Rationale: Pilar cyst mainly occurs on the scalp, but pilar cyst on the dorsum of hand has not been reported. Herein, we provide information to improve the clinical cognition of pilar cyst location. Patients concerns: A 76-year-old man presented with a round nodule on the opisthenar of his right hand for two months without any subjective symptoms. Diagnoses: Histological features of the lesion biopsy indicated the diagnosis of pilar cyst. Interventions: Surgical resection was made under local anesthesia. Outcomes: Complete recovery was achieved after surgery. Conclusion: Pilar cyst rarely occurs on the dorsum of hand and its diagnosis depends on histopathological examinations. Surgical resection is the only way to treat it.

Atypical Presentation of Pilar Cyst Over the Volar Aspect of the Thumb: A Case Report and Review of Literature

“…Epithelial cysts comprise epidermal cysts (80%) and pilar cysts (20%) [ 3 ]. Pilar cysts cannot be distinguished from epidermal cysts clinically and require histopathological examination [ 3 ]. They are noted in 5-10% of the general population, with a strong female preponderance [ 9 ].…”

“…They are noted in 5-10% of the general population, with a strong female preponderance [ 9 ]. Around 90% pilar cysts occur in the scalp region where hair follicles are abundant [ 3 ]. They are usually solitary, but could occasionally present as multi-focal lesions [ 4 , 10 - 11 ].…”

“…However, they could be complicated by additional pathology. Rupture of the capsule of the cyst, or imbalances between matrix metalloproteinases and their tissue inhibitors, could result in inflammation of the cyst, which would warrant delayed surgical excision [ 3 , 12 ]. Cysts may be infected with the human papillomavirus [ 13 ].…”

“…They appear as smooth, firm white-walled cysts without a punctum, and can easily be enucleated [ 2 ]. They commonly arise on the scalp where hair follicles are abundant, but can appear, in rare cases, in the axilla, groin, face, trunk, and extremities [ 3 ]. Though conventionally thought to arise only from hair-bearing skin, this notion has been disproved recently [ 3 , 4 ].…”

“…Pilar cysts of the hand are extremely rare, with only six case reports in the literature, to the authors’ knowledge [ 3 - 8 ]. Five of these reported cysts arising from the dorsal surface or at the level of the distal phalanx of the digits, with possible origins from hair follicles or the nail matrix [ 3 - 7 ], while one reported a cyst over the volar aspect of the index finger with a history of prior trauma [ 8 ]. We present a case of pilar cyst over the volar aspect of the thumb at the level of the proximal phalanx, with no history of trauma.…”