leiomyoma A well-circumscribed benign smooth muscle neoplasm characterized by the presence of spindle cells with cigar-shaped nuclei, interlacing fascicles, and a whorled pattern. DOID:127 ICD9:215.9 ICDO:8890/0 MESH:D007889 MONDO:0001572 NCIT:C3157 SCTID:146801000119103 UMLS:C0023267 fibroid fibroid neoplasm fibroid tumor leiomyoma leiomyoma, benign leiomyomatous neoplasm leiomyomatous neoplasm (morphologic abnormality) leiomyomatous tumor benign smooth muscle neoplasm