Lymphangioleiomyomatosis usually presents with dyspnea, cough, or pneumothorax (2,3,6). We describe LAM presenting with severe pulmonary hypertension (PH).
A 41-year-old female presented with four months of dyspnea on exertion, and peripheral edema. She had no history of ingesting diet pills, symptoms of a collagen vascular disease, or HIV risk factors. There was no personal or family history of thromboembolic disease, thrombophilia, or PH. She took no medications. Examination revealed a jugular venous pressure 10cm above the sternal angle, a pansystolic 2/6 murmur at the left lower sternal border, a right ventricular heave, and a palpable P2. Echocardiogram demonstrated a dilated right atrium and ventricle, an enlarged pulmonary artery and a peak right ventricular systolic pressure of 85 mmHg. A chest computed tomography (CT) scan showed a diffuse ground glass mosaic pattern. CT for thromboembolic disease was negative. A lung biopsy showed focal areas of smooth muscle hyperplasia in lymphatics and small airways without cystic change. There was focal HMB45 staining of the atypical smooth muscle cells. Pulmonary arterioles showed mild hypertensive changes. Within six months she developed New York Heart Association class IV right heart failure. Hemodynamic measurements revealed a CVP of 32mmHg, mean PAP of 75mmHg, cardiac index of 1.1 l/min/m2 and PVR of 945 dynes*sec*cm-5. Shortly thereafter the patient suffered a cardiac arrest. Autopsy revealed diffuse smooth muscle proliferation in the lymphatics, arterioles (Fig 1), and veins. Areas of classic LAM were present (Fig 2) that did not stain for HMB-45.
Based on series describing patients with LAM (2,3,6) this case is unique. In our case the patient presented with severe PH. Taylor et al report 5 of 28 patients had clinical, cardiographic, or autopsy evidence of right heart hypertrophy (2). Others do not comment, suggesting PH is a non-significant or unrecognized feature of LAM. One case of LAM with PH exists (1) however the diagnosis was made 4 years after a chylous effusion and PH was not the presenting feature. In our case, smooth muscle hyperplasia was predominant in the lymphatics and blood vessels while minimal in the airways. Histologically in LAM, there tends to be either a predominance of cystic lesions, or smooth muscle proliferation involving airways and lymphatics (6). Diffuse small cysts are usually seen on CT scans (6). Lastly the HMB-45 staining normally seen, was absent at autopsy in our case. However, not all LAM cells are immunoreactive with HMB-45, probably a reflection of the cellular heterogeneity of the disease (7). Therefore the minimal staining with HMB-45 does not preclude the diagnosis of LAM. Tuberous sclerosis was considered but normal intelligence, absence of epilepsy and skin findings made it unlikely. Pulmonary veno-occlusive disease was excluded at autopsy. Two similar cases of diffuse smooth muscle proliferation in the lungs with PH and right heart failure exist (4,5). Both patients were male so LAM is unlikely since LAM occurs exclusively in women.
We believe this represents the first reported case of LAM presenting as severe PH. In patients with diffuse smooth muscle proliferation but lacking cystic change or positive HMB-45 staining, LAM should still be considered.
P.R. MacEachern, None.