A rare cause of edema: sporadic lymphangioleiomyomatosis

History and clinical findings: A 45-year-old woman presented with marked edema of both lower extremities over 6 weeks for a nephrological work-up; she had gained 8 kg of body weight. Voiding was asymptomatic and she had a stable diuresis. The patient took oestrogens for contraception over 10 years. Blood pressure was normotensive. Serum-creatinine was 0.8 mg/dl; a slight microalbuminuria was noted. Left and right ventricular systolic function were normal. Diagnostic findings, treatment and clinical course: Computed tomography of the abdomen revealed a hemodynamically relevant obstruction of the venous blood flow or the lymphatic vessels as cause for the edema of both legs. Masses of lymphangioleiomyomas located around the v. cava inferior were documented. Biopsy of the masses proved a massive proliferation of smooth muscle cells and epitheloid cells with an immunohistochemically typical staining. Furthermore, CT revealed multiple pulmonary cysts in both lungs, results which are pathognomic for lymphangioleiomyomatosis (LAM). In our patient, the structural impairment of the lungs was not substantiated clinically, i.e. she had only slight dyspnoe during exertion. By mild diuretic treatment with HCT and fluid control, a moderate regression of the edema was achieved. At present, the mTOR inhibitor rapamycin as antiproliferative treatment is considered to reduce the retroperitoneal LAM-related masses on an individual basis. Conclusion: LAM is a rare genetically determined progressive disease occurring frequently in women in childbearing age. LAM is characterized by a proliferation of smooth muscle cells, lymphangioma, renal angiomyolipoma, pulmonary cysts and progressive destruction of lung parenchyma. Refractory edema can result from an obstruction of the venous blood and lymphatic flow by lymphangioma masses located paracaval, which was the impressive and first clinical feature of LAM in our case report.