© 2008 American Thoracic Society
S-LAM in a Man: The First Case ReportTo the Editor:We read with great interest the exciting case report by Dr. Schiavina and colleagues (1) describing the first case in a man with sporadic lymphangioleiomyomatosis (S-LAM). An editorial by Drs. McCormack and Moss accompanied the article (2). We agree with the editorial's comments that definite proof of the absence of tuberous sclerosis complex (TSC) in Schiavina and colleagues' case is challenging, especially in the light of potentially more sensitive genetic modalities to exclude TSC gene mutations. However, we would like to point out that the genetic methodology used by Schiavina and colleagues has been applied in other studies (3) and has a sensitivity of 80% based on the authors' experience (1), which makes the presence of TSC unlikely in this case. The negative results of the systematic clinical investigations looking for signs of TSC in the reported case are certainly reassuring. S-LAM is a rare disease that, until this case was published, seemed to occur only in women. McCormack and Moss (2) acknowledge the estimated prevalence of LAM based on European and American figures. We would like to add data from Australia and New Zealand, where LAM occurs with an estimated prevalence of 1.9 cases per million habitants for both countries, which seems to be higher than elsewhere. These data are derived from the recent survey done by our group, where a questionnaire with 38 questions about LAM was circulated to all women with LAM registered with three LAM patient support groups: the New Zealand LAM Charitable Trust, the Australian LAM Foundation, and the LAM Australasia Research Alliance (LARA). Of a total of 56 women registered in Australia and New Zealand, 7 had TSC and 2 had extrapulmonary LAM alone, giving a total of 47 cases of S-LAM. Data on the latter were analyzed. All subjects were female with mean age of (±SD) 40.2 (±9.3) years at first diagnosis and 32.3 (±8.9) years when presenting with the first respiratory symptoms. Demographic characteristics of patients and presenting features were typical, yet the diagnosis took 8 years to make, with LAM being significantly underrecognized. This highlights the need for increasing awareness of LAM outside the respiratory specialty. The case report of S-LAM in a man with no TSC is fascinating as it clearly highlights that, despite the several advances in LAM research and acquired knowledge regarding molecular and cellular pathology in this area, much still needs to be unraveled, especially relating to the influence of gender in this intriguing disease.
St. Vincent's Hospital FOOTNOTES Conflict of Interest Statement: None of the authors has a financial relationship with a commercial entity that has an interest in the subject of this manuscript. REFERENCES
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