A Case of Pilomatricoma in the Upper Arm: Sonographic and MR Imaging Findings

arising from the hair matrix (1-3). The preoperative diagnosis of this entity may be difficult because of its multiple manifestations (1), especially if the examining physician is unfamiliar with them. There have been some reports in the radiological literature which included the CT (2, 4, 5) and MR (2, 6-8) imaging findings of pilomatricoma however, to the best of our knowledge, there have been no reports in Korea on the sonographic and MR imaging findings of pilomatricoma involving the upper arm. Knowledge of the imaging findings of this uncommon tumor would provide clinicians with useful information and facilitate the correct management of this condition. In this article, we describe the imaging findings of a case of pilomatricoma involving the upper arm, with the emphasis being placed on the sonographic and MR imaging findings and a review of the literature.