Extra Uterine Leiomyoma with “Amianthoid-like” Fibers

Abstract

Uterine leiomyoma is a benign smooth muscle neoplasm, typically arising in uterus and deep soft tissue. In the present case, tumour size of 7×4×3 cm identified on subserosal aspect of uterus. Grossly, tumour was well circumscribed, whitish nodule and on cut surface whitish whirls were seen. Microscopic examination showed a cellular spindle cell population with numerous eosinophilic amianthoid-like fibers. Immunohistochemically, the tumour showed positivity for H-caldesmon, desmin, alpha smooth-muscle actin, and negativity for CD10. The finding of amianthoid-like fibers in leiomyoma is very rare. Amianthoid fibers are hyalinized collagen mats. It extends the histomorphological spectrum of leiomyomas. Amianthoid fibers are very characteristics of “intra nodal palisaded myofibroblastoma”. Presence of “Amianthoid-like fibers” creates histomorphologically similar picture between leiomyoma and “intra nodal palisaded myofibroblastoma”. Pathologist should be aware of such variant of leiomyoma that contains “Amianthoid-like fibers” to avoid confusion with other tumours.

Keywords

• actin desmin
• h-caldesmon
• palisaded myofibroblastoma