Rationale: The three previously reported cases of conclusively documented pulmonary lymphangioleiomyomatosis (LAM) in men were associated with definite or probable tuberous sclerosis complex (TSC).
Objectives: To describe an unequivocal case of pulmonary LAM occurring in a man with no clinical or genotypic evidence of TSC.
Methods: At high-resolution computed tomography, a 37-year-old phenotypically and karyotypically normal man with left pneumothorax and massive pulmonary collapse had widespread thin-walled cysts throughout both lungs. Histological diagnosis of LAM was performed on biopsy material, and immunohistochemically confirmed with the HMB-45 monoclonal antibody.
Measurements and main results: Remarkably, the HMB-45-positive cells lining the cysts also showed strong reactivity for estrogen and progesterone receptor proteins. TSC was clinically excluded, and TSC1 and TSC2 germline mutations were not detected at DNA analysis.
Conclusions: This article indicates that occurrence of LAM may be possible in a chromosomally normal man unaffected by TSC. On diagnostic grounds, the possibility of LAM should be borne in mind when diffuse cystic lung disease occurs in a man, even in the absence of signs of TSC.