Unilateral lymphangioleiomyomatosis

Pulmonary involvement in tuberous sclerosis complex (TSC) resembles lymphangioleiomyomatosis (LAM) in its clinical, radiologic, and histopathological features. Typical high-resolution computed tomography (HRCT) findings are of bilateral thin-walled cysts symmetrically throughout both lungs, with associated increase in lung volumes. Atypical cases have been described; and we report a case of biopsy proven, focal unilateral disease. The presence of nodules has been reported in association with TSC that histologically are composed of proliferated type II pneumocytes. We discuss other atypical cases of TSC and sporadic LAM and review current concepts of the pathogenesis of the 2 diseases, with reference to our case.