The stone beneath my skin: Pilomatricoma in a young Nepalese girl

Abstract

Pilomatricoma is a rare and benign tumor affecting children and adolescents. It originates from the matrix cells of hair follicles, the usual sites being head-neck and upper extremities. Due to its rarity, it is often misdiagnosed delaying definitive treatment. We report a case of pilomatricoma over the left gluteal region in a young Nepalese girl that was initially thought to be a calcified granuloma. A six-year-old girl presented with a painful swelling over the left buttock for one year that was gradually increasing in size. On examination, a solitary, well-circumscribed, tender swelling with hard consistency and a bumpy irregular surface measuring 3×2 cm was noted over the subcutaneous plane of the left gluteal region. Surgical excision of the mass was done which demonstrated features of pilomatricoma on histopathological examination (HPE). She recovered and remained disease-free at one year follow-up. This case highlights one of the handful presentations of pilomatricoma involving the buttock. Pilomatricoma is rarely considered a differential diagnosis of benign masses, the diagnosis of which is ascertained mostly after an HPE of the excised specimen. Surgical excision with clear margins is not only diagnostic but therapeutic in most situations.