Pulmonary "inflammatory Leiomyosarcomas" Are Indolent Tumors with Diploid Genomes and No Convincing Rhabdomyoblastic Differentiation

Yu Chien Kao, Chien Tzu Kuo, Po Yen Kuo, Hsuan Ying Huang, Tzu Pin Lu, Tsung Han Hsieh, Christopher D.M. Fletcher, Jen Chieh Lee

研究成果: 雜誌貢獻文章同行評審


Inflammatory leiomyosarcoma is a rare myogenic tumor with striking inflammatory infiltrates and a specific genomic pattern of near-haploidization despite exception(s). Recent studies demonstrated that inflammatory leiomyosarcoma shares substantially overlapping features with histiocyte-rich rhabdomyoblastic tumor, including expression of rhabdomyoblastic markers such as myogenin, MyoD1, and PAX7 and a high prevalence of genomic near-haploidization, suggesting that they represent a unifying entity, for which the term inflammatory rhabdomyoblastic tumor was coined. In this study, we identified 4 pulmonary tumors histologically typical of inflammatory leiomyosarcomas, all in men (aged 26 to 49), presented as slow-growing well-defined nodules ranging from 1.4 to 3.5 cm, and following uneventful postoperative courses. All tumors were positive for desmin immunostaining, while only 1 and 2 were focally positive for smooth muscle actin and smooth muscle myosin heavy chain, respectively. They showed no expression of myogenin, MyoD1, or PAX7 by immunohistochemistry or RNA sequencing. Copy number analyses by whole-exome sequencing (N=1), OncoScan single-nucleotide polymorphism array (2), and fluorescence in situ hybridization (1) revealed/suggested diploid genomes. Together with a previously reported case, all these pulmonary "inflammatory leiomyosarcomas" seemed clinically, pathologically, and genomically alike. Despite a superficial resemblance to conventional inflammatory leiomyosarcoma in somatic soft tissues (now preferably termed inflammatory rhabdomyoblastic tumor), they differ in the lack of convincing rhabdomyoblastic differentiation and genomic near-haploidization. Therefore, we propose that these pulmonary tumors probably represent a distinct entity, for which the exact line of differentiation, and perhaps the most suitable terminology to better reflect its nature, remains to be determined. The term inflammatory rhabdomyoblastic tumor seems inappropriate for this group of tumors.

頁(從 - 到)424-433
期刊American Journal of Surgical Pathology
出版狀態已發佈 - 3月 1 2022

ASJC Scopus subject areas

  • 解剖學
  • 手術
  • 病理學與法醫學


深入研究「Pulmonary "inflammatory Leiomyosarcomas" Are Indolent Tumors with Diploid Genomes and No Convincing Rhabdomyoblastic Differentiation」主題。共同形成了獨特的指紋。