Lymphangioleiomyomatosis (LAM) is a rare parenchymal lung disease, which affects young women of childbearing age and is characterized pathologically by proliferation of interstitial smooth muscle and formation of cysts in the lung. While LAM is usually predominantly a respiratory disorder, it can also initially involve other extrapulmonary organs. We report the case of a 35-year-old Chinese woman, who presented with a 4-week history of left thigh swelling which was found to be secondary to compression of pelvic veins by a mass lesion. The latter was found histologically to show LAM. Despite the patient being asymptomatic and displaying normal lung function, a thoracic high resolution CT scan showed typical features of early LAM. This case further illustrates that LAM can have multisystem involvement, and demonstrates the importance of being aware of the diagnosis in cases presenting with extrapulmonary manifestation, in order that patients are diagnosed and managed appropriately.