Pulmonary giant cysts – an extraordinary presentation of LAM?

A. Taha, P. Dorn, R. A. Schmid

Objective

Pulmonary lymphangioleiomyomatosis (LAM) is a rare lung disease usually affecting young women. Categorized as a generally benign mesenchymal neoplasm with perivascular epitheloid cell differentiation its most common presentations are restricticve (progressive dyspnea or spontaneous pneumothorax). The diagnosis of pulmonary LAM may be strongly suggested by the clinical presentation and findings at the CT-scan. Homogeneous, thin-walled and small cysts (2-40 mm in diameter) are typical for this disease.

Methods

We report a case of a 54-year-old female smoker (60py) who was referred to our hospital by her pulmonologist for evaluation of multiple slow growing bilateral giant (12cm) pulmonary cysts over 4 years. Despite an unchanged stress dyspnea, there were no further clinical symptoms. Hematological survey was unsuggestive of echinococcosis and aspergillosis. There was only a COPD Gold I (FEV1 1.53l (62%)) in medical history. In addition, in 1998, a thoracoscopic bullectomy was performed because of spontaneous pneumothorax, histopathological examination showed subpleural located lymphangioleiomyomatosis. Then, no further therapy was initiated.

To confirm diagnosis and to exclude malignant disease, video-assisted thoracoscopic cyst resection followed by bilateral pleurodesis was performed. The postoperative course was uneventful, the patient recovered well.

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Results

Histological examination showed a typical proliferation of smooth muscle cells, but no immunoacting for HMB-45, which is a immunohistochemical marker and determines a particular subtype of perivascular smooth muscle cells. No findings for an infectious or malignant etiology.

Conclusion

Despite of missing typical immunohistochemical characteristics, LAM is strongly suspected in our patient because of the radiological and histopathological findings. Consequently, we report a rare case of pulmonary LAM in a patient with giant cysts as incidental finding. Although some studies support a hormonal therapy with medroxyprogesterone acetate, tamoxifen or luteinizing hormone-releasing hormone, no therapy is of proven benefit. Because of progressive respiratory failure, patients with LAM may require lung transplantation.