Isolated congenital spleen agenesis: A rare cause of chronic thromboembolic pulmonary hypertension in an adult

  This report describes a case of isolated congenital spleen agenesis complicated by chronic thromboembolic pulmonary hypertension (CTPH) in a 44‐year‐old female patient. The patient had increasing exertional dyspnoea and thrombocytosis. An echocardiogram showed severe pulmonary hypertension and right ventricular hypertrophy, and contrast‐enhanced chest CT revealed multiple thromboemboli within both pulmonary arteries. A perfusion lung scan demonstrated multiple segmental defects and no spleen was detected by abdominal CT, ultrasonography or scintigraphy. Comprehensive clinical examinations disclosed no evidence of a thrombus elsewhere or of an associated malformation such as a cardiac anomaly. Anticoagulation therapy was started, and a perfusion lung scan revealed partial improvement of the hypoperfusion in the right lower lobe. However, repeat echocardiography showed the pulmonary hypertension persisting for 1 year. The multiple segmental defects in the perfusion lung scans were also persistent. Collectively, a diagnosis of CTPH with isolated congenital spleen agenesis was established. This is the first documented case of CTPH in an adult with isolated congenital asplenia. Although congenital spleen agenesis is a rare condition, this case report suggests that this possibility should be considered when a diagnosis of CTPH and thrombocytosis is made.