Unusual Presentation of Recurrent Pyogenic Bilateral Psoas Abscess Causing Bilateral Pulmonary Embolism by Iliac Vein Compression.

Background: Psoas abscesses are a known cause of back pain, but they have not been reported as a cause of acute lower extremity thromboses and bilateral pulmonary emboli. We report a patient with bilateral psoas abscesses causing extensive pulmonary emboli through compression of the iliac vein.

Case Report: A 47-year-old man presented with bilateral leg swelling over 4 weeks. Physical examination revealed a thin male with bilateral leg swelling, extending to the thigh on his left side. He had hemoglobin of 10.5 g/dl, leukocytosis of 16 000/ml, and an elevated D-dimer. A computed tomography (CT) angiogram of his chest showed extensive bilateral pulmonary emboli and infarcts. He remained febrile with vague flank pain, prompting a CT of his abdomen and pelvis that showed large, multiloculated, septated, bilateral psoas abscesses with compression of the left femoral vein by the left psoas abscess and a thrombus distal to the occlusion. Two liters of pus was drained from the left psoas abscess by CT-guidance, and although the Gram staining showed Gram-positive cocci in clusters, cultures from the abscess and blood were negative. A repeat CT showed resolution of the abscesses, and the drain was removed. He was discharged to a nursing home to complete a course of intravenous antibiotics and anticoagulation.

Conclusions: Although the infectious complications of psoas abscesses have been described in the literature, the mechanical complications of bilateral psoas abscesses are lacking. It is important to assess for complete resolution of psoas abscesses through follow-up imaging to prevent venous thromboembolic events.