Left-sided pleural effusion secondary to splenic vein thrombosis. A previously unrecognized relationship.

The association of left-sided pleural effusion and subcapsular splenic hematoma was reported in 1980. We describe a patient in whom a left-sided pleural effusion resulted from splenic vein thrombosis, a relationship not previously reported. Splenectomy was performed, demonstrating the spleen to be enlarged and hemorrhagic. The pleural effusion did not recur after splenectomy. The three effusions due to splenic hematomas reported previously cleared only after splenectomy, suggesting splenectomy may be necessary to prevent reaccumulation. We propose possible pathophysiologic mechanisms and recommend that splenic vein thrombosis be considered in the differential diagnosis of unexplained left-sided pleural effusions.