Myofibroma

The findings are those of a very interesting soft tissue neoplasm which I believe falls under the appellation of a solitary myofibroma. This lesion appears to exhibit an intravascular localization. The cardinal hallmarks of this benign soft tissue neoplasm are well exemplified by this case and include a dichotomous composition characterized by smooth muscle myomatous nodules with interposed hemangiopericytomatous-like foci. Histologically these lesions invariably exhibit a very characteristic biphasic pattern with whorled areas of spindled cells showing hyalinization and chondroid-like alteration of the background matrix with interposed more cellular spindled hypervascular hemangiopericytomatous areas. Phenotypically the myomatous nodules are desmin negative, although they do express smooth muscle actin, a phenotypic finding which mirrors that observed in this case. Their intravascular tendency is a phenomenon that is quite most uncommon but has been previously reported.