Inclusion bodies are not uncommon in angioleiomyoma.

Background Leiomyomas with eosinophilic intracytoplasmic inclusion bodies have been described in the urinary bladder, brain, gastrointestinal tract, uterus, and oral cavity but not in the skin. Prompted by our recent experience with a case of cutaneous angioleiomyoma with many inclusion bodies, we hypothesized that similar cases might have been previously overlooked. Methods We retrospectively reviewed 30 cases of angioleiomyoma and 10 cases of piloleiomyoma focusing on inclusion bodies. Results More than 18 inclusion bodies per 250 μm square were detected in 5 cases of angioleiomyoma, fewer than 11 bodies in 20 cases, and none in 5 cases. For the case with numerous inclusion bodies throughout the specimen, special staining was needed to make a diagnosis. No inclusion bodies were found in the piloleiomyoma. Conclusion Inclusion bodies were relatively common in angioleiomyomas and could occasionally be numerous. It may serve as a differentiation point from piloleiomyomas. Due to the fact that the presence of multiple eosinophilic intracytoplasmic inclusions can result in a rhabdoid appearance and make diagnosis challenging, we should be aware of this feature in angioleiomyomas. This article is protected by copyright. All rights reserved.