INTRODUCTION:The immediate postpartum period is recognized as a high-risk period for pulmonary embolism(PE). Hence PE would be a primary suspect diagnosis with the presenting symptoms of dyspnea, chest pain, cough, and/or hemoptysis here. Pumonary artery endothelial sarcoma(PAS) is a rare malignancy, and can present with clinical and radiologic features indistinguishable from either acute PE or Chronic Thromboembolic Pulmonary Hypertension(CTEPH). But progressive weight loss, anemia, and fever are unusual for PE.
CASE PRESENTATION:41 year old woman developed subacute dyspnea five months into her second pregnancy. Two weeks after the delivery, she developed acute dyspnea and chest pain requiring hospitalization. A spiral CT chest(CTA) revealed an extensive filling defect involving the common pulmonary trunk, left and right main pulmonary arteries, with dilatation of the right pulmonary artery, and was diagnosed with acute pulmonary embolism. Also noted were peripheral pleural based pulmonary opacities in both the lower lobes, suspicious for “Hampton’s Hump” and mosaic hypoperfusion. No pathologic hilar or mediastinal adenopathy. Duplex USG of the lower extremities showed no DVT. She was anticoagulated with heparin and then coumadin. However, dyspnea with minimal activity persisted despite therapeutic anticoagulation. She had no significant weight changes. There was no history of diet pill or oral contraceptive use. Few months later she developed hemoptysis. Ventilation Perfusion Scan: multiple mismatched lobar, segmental, and subsegmental perfusion defects. 2&8 months later, repeat CT chest showed no change in the large saddle type embolus. PFT: Normal Flows and Volumes. DLCO was 58 % of predicted. ABG 7.48/31/60.8/92%/HCO3 22.4. Respiratory alkalosis with resting hypoxemia. Echocardiogram: Estimated Systolic PAP 75 mm Hg. Severe RA and RV enlargement with a late positive bubble sign, and mild TR. CBC and chemistry panel: unremarkable. HIV seronegative. Anticardiolipin antibody/Factor V Leiden negative. Protein C and S normal. Right Heart Catheterization. RA pressure 4. PA 95/19 with a mean PAP of 45. PCWP 4. Cardiac output 3.7. PVR 886. Pulmonary Angiogram : Right pulmonary artery angiogram was notable for subtotal occlusion with bulky intraluminal filling defects with little flow distally. The left pulmonary angiogram also had extensive filling defects, with abrupt occlusion of the left descending lower lobe artery after the lingular take off. Attempted pulmonary thromboendarterectomy trial: Jello-like mass suspicious for tumor was found filling the pulmonary artery trunks. Debulking performed. Immunohistochemistry and pathology revealed PAS.
DISCUSSIONS:PAS mimics acute or chronic pulmonary thromboembolism with similar findings on clinical presentation, physical findings, CT/MRI, VQ scan and even pulmonary angiogram. However the following features on CT/MRI favor the diagnosis of PAS over CTEPH: heterogeneous enhancing soft tissue density, a low-attenuation filling defect occupying the entire luminal diameter of the main or proximal pulmonary artery, expansion of any segment of the pulmonary artery with extensive intraluminal filling defect, extraluminal extension, and smooth vascular tapering without abrupt narrowings and cut-offs. HRCT findings of mosaic pattern of lung attenuation, lung parenchymal consolidative changes/subpleural nodules can resemble acute PE/CTEPH. VQ scanning usually does not show the typical bilateral segmental and subsegmental perfusion defects but rather normal findings, an inhomogeneous perfusion pattern, or unilateral abnormalities. However the VQ findings are also not specific for neither condition as evident from the present case. Pulmonary angiography typically shows intraluminal masses and lung perfusion abnormalities with a smooth tapering of pulmonary arteries and intraluminal mobile pedunculated lesions.
CONCLUSION:Even in the presence of a hypercoagulable state represented by pregnancy and the post partum period, the persistence of symptoms and intraluminal filling defects occupying the entire luminal diameter of the main or proximal pulmonary artery despite adequate anticoagulation, with other relatively specific CT/MRI findings indicate the possibility of PAS.
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