Pilomatrixoma imitating infantile hemangioma.

Many lesions can masquerade as infantile hemangioma, the most common tumor of infancy. We describe an infant with pilomatrixoma mimicking hemangioma. The patient presented at 8 months of age with an 1.2-cm, red, asymptomatic lesion of the right ear. The mass was noted at 4 months of age and subsequently enlarged. Ultrasonography demonstrated hypervascularity "consistent with infantile hemangioma," and the infant was observed. At 12 months of age, the lesion continued to expand and became ulcerated; it was excised, and histopathology showed pilomatrixoma. Diagnostic confusion was caused by atypical features of this pilomatrixoma that overlapped with infantile hemangioma: onset in infancy, ulceration, red color, and fast flow on imaging. Deviation from the predictable clinical features of an infantile hemangioma should prompt consideration for other types of pediatric lesions, including pilomatrixoma.