INTRODUCTION: Sarcoidosis is a poorly understood granulomatous disease that involves the lung and intrathoracic lymph nodes in more than 90% of patients.We report a unique case of a patient with sarcoidosis who presented with features suggestive of pulmonary embolism.
CASE PRESENTATION: A 68-year-old lady with history of hypertension and sarcoidosis presented with complaint of shortness of breath, chest pain and palpitation. Chest pain was localized to the left side with no radiation and there was no nausea, vomiting, diaphoresis, gastrointestinal or genitourinary complaints. On exam, she was tachycardic and tachypneic with blood pressure 185/102. Lungs were clear and remaining examination was unremarkable. Laboratory results reveal troponin of 0.24, blood gas- pH 7.47, pCO2 33.7mmHg,pO2 66.6mmHg and O2 sat 95.2% on rooom air.CBC and chemistry were normal. Chest xray(CXR) revealed bilateral hilar fullness with no infiltrates.EKG showed sinus tachycardia @110/min,T wave inversion in leads 3, V1 to V4, Q waves in lead 3 and an S wave in lead 1. A diagnosis of pulmonary embolism was entertained to rule out myocardial ischemia. Patient was started on anticoagulation and ventilation-perfusion(V/Q) scan and serial cardiac enzymes ordered.V/Q scan revealed normal ventilation with a large perfusion defect in the left lung field and small defect in the right lower lobe(high probabilty for Pulmonary Embolism). Echocardiography showed right ventricular dilatation, Left ventricular hypertrophy and ejection fraction of 55%. Lower extremity venous doppler was negative. Chest CT scan revealed enlarged bilateral hilar and mediastinal adenopathies encasing and compressing the left pulmonary artery(PA)with cut of flow and minimal compression of the right PA. V/Q mismatch now considered to be due to extrinsic compression of the left main pulmonary artery by adenopathies secondary to sarcoidosis.Bronchoscopy was negative for malignancy and all cultures negative. Anticoagulation was discontinued and steroid therapy commenced. Her functional capacity improved after about 2 weeks and repeat CT chest was said to have shown reduced lymphadenopathies.
DISCUSSIONS: The clinical presentation of sarcoidosis are widely varied.The histologic hallmark of sarcoidosis is the noncaseating(nonnecrotizing) granuloma composed of epitheloid cells and multinucleated giant cells. Special staining for acid fast bacilli and fungi should be performed to exclude infectious etiologies.Mechanisms of vascular involvement in sarcoidosis include (a)external compression by enlarged lymph nodes (b)granuloma surrounding the vessel walls and (c)granulomatous infiltration of the vessel wall.Compression of the pulmonary arteries by adenopathy is rare and may result in decreased pulmonary artery perfusion mimiking pulmonary artery embolism. The extent of compression will vary proportionately with the degree of adenopathy. Granulomata tends to surround small blood vessels, causing the loss of lung alveolocapillary transfer surface and decreased diffusing capacity.Granulomatous infiltration of the vessel walls may occur, and there may be intimal involvement, vascular thrombosis, and even vessel wall destruction.The extent of granulomatous vascular involvement was related to that of parenchymal granuloma.Chest CT scan demonstrating extrinsic compression of both PA by adenopathies spared this patient a long and unnecessary anticoagulation therapy.
CONCLUSION: Physicians should keep in mind that lung ventilation-perfusion mismatch in Sarcoid is not always due to thromboembolic disease and may be secondary to external compression by lymphadenopathies and in those cases such patients would respond to treatment of Sarcoid rather than anticoagulation.
DISCLOSURE: Adekunle Adekola, None.