Lymphangioleiomyomatosis

Abstract

Background: Lymphangioleiomyomatosis (LAM) is a rare systemic disease that occurs sporadically (S/LAM) or as part of tuberous sclerosis (TS/LAM). LAM is characterized by proliferation of abnormal smooth muscle cells. This disease clinically manifests as dyspnea on exertion and pneumothorax. Lymphadenopathy in the abdominal and pelvic region leading to lymphatic obstruction can also occur. LAM is associated with kidney angiomyolipoma and meningioma. The disease is diagnosed histologically and/or using typical high-resolution computed tomography findings and anamnestic information. In histopathological studies, the diagnosis is supported by detection of characteristic LAM cells. Mammalian target of rapamycin (mTOR) inhibitors are possible treatment options.

Material and methods: Ten consecutive patients diagnosed with LAM and pulmonary manifestation (eight with S/LAM and two with TS/LAM) in 2002-2018 were retrospectively analyzed. Their individual clinical characteristics and our treatment experience are described.

Results: The patients varied in terms of disease stage. The best predictors of prognosis were lung function parameters (forced vital capacity, forced expiratory volume in 1 second, and diffusing capacity for carbon monoxide). Four patients are currently being treated with mTOR inhibitors. This treatment stabilized lung functions in all four patients. The median follow-up was 48 months (12-132 months). Median survival was not achieved and only three patients died.

Conclusion: An interdisciplinary approach is required to care for LAM patients. Cooperation of pneumologists, surgeons, oncologists, and geneticists is needed. Treatment with mTOR inhibitors led to stabilization in our patients. The side effects were well managed.

Keywords: lymphangioleiomyomatosis; rapamycin; sirolimus.