Frequency of undiagnosed cystic lung disease in patients with sporadic renal angiomyolipomas

Objective: The aim of this study was to assess the frequency of undiagnosed cystic lung lesions suggestive of pulmonary lymphangioleiomyomatosis (LAM) in patients who received a diagnosis of sporadic renal angiomyolipomas (AMLs). Methods: We conducted a retrospective review of CT scans of the chest or abdomen for cystic lung lesions on 176 adult patients who received a diagnosis of sporadic renal AML during a 10-year period, 1997 to 2006, and comparison with chest CT scans of 176 control subjects without renal AML but matched for age, sex, and smoking history. Patients presenting with suspected or known pulmonary LAM and those with underlying tuberous sclerosis were excluded. Results: Sporadic renal AML was diagnosed in 176 patients with a median age of 58 years (range, 20-91 years), the majority of whom were women (81.8%). Renal tumor was an incidental finding on imaging studies for most patients (90.3%). Nineteen patients (10.8%) had one or more cystic lung lesions and included nine patients (5.1%) with four or more cysts, all of whom were women. In comparison, eight control subjects (4.6%) had one to three cystic lung lesions and none of them exhibited four or more cysts. None of the patients with renal AML and cystic lung lesions, including six women with 10 or more cysts, had undergone an evaluation of their cystic lung disease. Conclusions: We conclude that a significant portion of women with sporadic renal AMLs exhibit cystic lung lesions suggestive of pulmonary LAM but may remain undiagnosed. Coexistence of pulmonary LAM should be considered in women incidentally found to have sporadic renal AMLs.