Abstract: A 23-year-old female presented with two nodules on her right upper arm for over 1 year after mosquito bites, and the nodules increased and developed to red cyst after 3 months. The  histopathologic features of the lesion were in accordance with bullous pilomatricoma. MRI showed long T1 and short T2 signal in the fat layer, protruding to the skin surface, and long T2 signal at the outer edge. The lesions were healed well after complete resection.

Key words: bullous pilomatricoma, magnetic resonance imaging