Comprehensive genetic analysis of laryngeal leiomyosarcoma by next generation sequencing: a case report

Sarcomas are an uncommon miscellaneous group of mesenchymal tumours with a steady incidence rate of 50 cases per million population. Among the malignant sarcomas, leiomyosarcoma (LMS) is a neoplasm with pure smooth muscle differentiation that is usually divided into three subgroups on the basis of anatomical localization: LMS of the retroperitoneum, LMS of the large blood vessel and LMS of the non-retroperitoneal soft tissue sites. Laryngeal LMS (LLMS) is a mesenchymal malignant tumor that occurs only very infrequently, and <50 cases have been described in the literature worldwide. Even so, a few reports have described the molecular landscape of LMSs, whereas the molecular profiling of LLMS has yet to be explored, to the best of our knowledge. The present case study describes the case of a 67-year-old male patient who presented with symptoms of dysphagia. A MRI scan of the larynx revealed a polypoid lesion that was localized to the glottis. A total laryngectomy with bilateral lymphadenectomy was subsequently performed, and a histopathological examination revealed the presence of LLMS. In order to assess the genetic landscape of LLMS, target sequencing of 409 cancer-associated genes was performed in order to identify genetic alterations associated with this rare tumor type. Among a total of 231 molecular alterations, 178 single-nucleotide variants and 53 copy number variations were detected. The molecular analysis allowed the identification of somatic alterations in a number of genes, including MYC, fibroblast growth factor receptor 1, aurora kinase A, PTEN and TP53. Taken together, the results of the present study have confirmed the presence of molecular alterations previously described for non-laryngeal soft tissue sarcomas, and also revealed novel somatic genetic alterations that are specific for LLMS. An investigation of the molecular profile has enabled a greater insight into elucidating the pathogenesis of this rare tumor type, and these findings may lead to the identification of novel therapeutic targets, especially for advanced tumors in the absence of other therapeutic options.