Leiomyosarcoma with Isolated Metastasis to the Extraocular Muscle: A Case Report involving Whole-Exome Sequencing

Abstract

Background: Whole-genome sequencing analysis of leiomyosarcoma of the orbit, a rare condition, has seldom been reported. Here, we describe a case of metastatic orbital leiomyosarcoma, which was confirmed before the diagnosis of the primary tumor.Case presentation: A 71-year-old man presented with total ptosis of the right eyelid. Limitations of supraduction and infraduction of the right eye were present, resulting in left hypotropia at the primary gaze. Enhanced magnetic resonance imaging of the right orbit revealed an extraconal, peripherally enhancing mass arising from the superior rectus muscle. The diagnosis of leiomyosarcoma was confirmed by histopathologic examination. Next-generation sequencing revealed the absence of mutations such as TP53, RB1, and ATRX, which were previously detected in leiomyosarcoma. Conclusions: This case indicates that in patients with ocular movement limitation and ptosis, an orbital mass on the external ocular muscle should be considered, along with the possibility of metastatic lesions. Systemic examination and excisional biopsy should be performed.