Pilomatricoma at an unusual site mimicking malignancy: a case report

Pilomatricoma is a benign adnexal tumor of hair matrix origin, commonly found in the head and neck region.Bullous pilomatricoma is a rare variant that is frequently misdiagnosed.Occurrence at unusual sites, such as the trunk or back, is rare and may lead to diagnostic confusion.A 23-year-old male presented with a gradually increasing mass over the right lower back for 2 months.On local examination, it was a soft, mobile, tender, subcutaneous nodule with superficial blister formation measuring approximately 3 × 2.5 cm.Fine-needle aspiration cytology was suggestive of malignancy.Based on clinical and cytological suspicion, a wide local excision was performed.Histopathological examination revealed features consistent with pilomatricoma.Pilomatricoma at uncommon sites can mimic malignancy both clinically and cytologically.The bullous variant of pilomatricoma represents only about 2% of all reported pilomatricoma cases.Awareness of its varied presentation is essential to avoid overdiagnosis and overtreatment.Complete excision remains the treatment of choice with excellent prognosis.