The clear cell variant of epithelioid intravenous leiomyomatosis of the uterus: report of a case.

A case of very rare uterine clear cell epithelioid leiomyomatosis is reported. The patient presented with a recurrent pelvic mass after hysterectomy 2 years earlier. The recurrent tumor was located mainly in the vessels of the broad ligament as worm-like plugs. The reviewed hysterectomy specimen showed a typical multi-lobulated intramural mass together with worm-like plugs within the myometrial vessels. Computer tomography exhibited metastatic nodules in both lungs. According to an histological examination, all the tumor cells were of epithelioid type and contained abundant clear cytoplasm. Characteristic large, thick-walled blood vessels were observed. Immunohistochemical staining and ultrastructural examination supported smooth-muscle origin in this case. Electron microscopic study revealed that the clear cytoplasm was attributed to the presence of numerous dilated mitochondria that had lost their cristae. The patient is still alive with the disease 28 months after surgery.