Extrathoracic angiomyolipomas in lymphangioleiomyomatosis

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disorder that affects women and can lead to serious respiratory impairment. Since Bourneville's tuberous sclerosis (TS) was first reported, the striking similarities between the two entities have led many to believe that LAM is a forme fruste of TS. This is suggested by reports that angiomyolipomas, rare tumours in themselves, are reported in 40-80% of TS patients and occur in 15-30% of LAM patients. A retrospective chart review was conducted of 14 patients that presented to our institution with a diagnosis of LAM. We sought to document the clinical manifestations, particularly the incidence and location of extrathoracic tumours, in order to further support the hypothesis that LAM is a forme fruste of TS. Twelve patients had premenopausal onset of symptoms and two postmenopausal. The diagnosis was confirmed histologically (n = 12) and/or by computed tomography (CT) scan of the thorax (n = 12). Imaging investigations revealed extrathoracic tumours in 12 of 14 patients (86%). Eight of the 14 patients (57%) had renal tumours consistent with angiomyolipomas (bilateral in five patients). Only one patient had renal symptoms (flank pain and haematuria). All had normal serum creatinine, one had a reduced creatinine clearance. Extrathoracic nonrenal tumours were discovered in the pancreas, adrenals and uterus, findings previously unreported in LAM. In summary, the incidence of extrathoracic tumours in lymphangioleiomyomatosis patients is much higher than previously reported in the literature. This increased association supports the theory that lymphangioleiomyomatosis and tuberous sclerosis represent part of a spectrum of a similar disease process.