ABSTRACT
We present 3 cases of extrapulmonary lymphangioleiomyomatosis (LAM) identified incidentally in the uterine corpus and pelvic nodes resected for other reasons. One patient, a 47-yr-old female with corpus cancer, underwent a total hysterectomy and nodal dissection; the other 2 patients, aged 44 and 49 yr, underwent simple hysterectomy for corpus leiomyomas. None of the patients had evidence of tuberous sclerosis complex or any significant lesions in other organs. An area of spindle cell proliferation, intimately associated with dilated and tortuous lymphatic vessels, was found in the myometrium of all 3 patients, and nodal involvement with spindle cell proliferation was observed in the patient with corpus cancer. The spindle cells had faintly eosinophilic cytoplasm and a bland appearance. They were immunoreactive for α-SMA, gp100 (HMB45), and Melan-A. Tumor cell clusters lined with a single layer of lymphatic endothelium were floating in the lymphatic vessel lumen. These lesions were diagnosed as lymphangioleiomyoma in the uterine corpus and associated lymph nodes. Two of the cases seemed to be the earliest manifestations of extrapulmonary LAM, and the other case represents early-phase metastasis of LAM from the uterus. The present cases support the speculation that the uterus is the primary source of LAM cells.