Multiple pilomatricomas: cutaneous marker for myotonic dystrophy.

We report an interesting case of multiple pilomatricomas (MPs) in a patient with myotonic dystrophy. Pilomatricoma (calcifying epithelioma of Malherbe) is a benign tumor of hair matrix derivation. It usually occurs as a solitary, firm, asymptomatic nodule on the face, neck, or proximal upper extremity. Most pilomatricomas have activating mutations in the ss-catenin gene (encoded by CTNNB1), leading to involvement of the WNT signaling pathway. The resulting gene product activates transcription leading to tumorigenesis [1]. Since the onset of MPs may precede the signs of myotonic dystrophy, they can serve as potential early cutaneous markers for this systemic disease.