Extrapulmonary lymphangioleiomyomatosis in pelvic and paraaortic lymph nodes associated with uterine cancer: a report of 3 cases.

We report 3 cases of extrapulmonary lymphangioleiomyomatosis incidentally found in pelvic and paraaortic lymph nodes in association with uterine cancers. Three women, 47-year-old, 59-year-old, and 71-year-old, respectively, had uterine cancers and underwent hysterectomy, bilateral salpingo-oophorectomy, and pelvic and paraaortic lymph node excision. None of the 3 patients had tuberous sclerosis complex or lymphangioleiomyomatosis in other organs. None had any history of extrinsic hormonal administration. The postoperative pathologic diagnoses were uterine cervical squamous cell carcinoma for the first patient and endometrioid adenocarcinomas for the second and the third patients. Besides these malignant lesions, all 3 patients showed spindle cell proliferation, 2 to 5 mm in size, in 1 to 8 foci of the pelvic and paraaortic lymph nodes. The spindle cells having small polygonal nuclei and inconspicuous nucleoli with palely eosinophilic cytoplasm, reminiscent of immature smooth muscle cells, proliferated in nested and whorling patterns. Neither cellular atypia nor mitotic figures were observed. Immunohistochemically, these spindle cells were positive for α-Smooth Muscle Actin, Desmin, HMB45, Microphthalmia Transcription Factor, Estrogen receptor, and Progesterone receptor. And the network of the vascular-like channels surrounded by these spindle cells was positive for D2-40. From the pathologic and immunohistochemical findings, the spindle cell proliferation in the lymph nodes is best interpreted as lymphangioleiomyomatosis.