Multiple venous and arterial thromboses of the gallbladder causing acute cholecystitis. A previously undescribed complication of essential thrombocythemia.

Well established complications of essential thrombocythemia are multiple thrombohemorrhagic phenomena in various abdominal organs. We describe the case of a 22 year old man with essential thrombocythemia and thrombosis of the mesenteric and splenic veins as well as cavernomatous transformation of the portal vein. The patient also had a splenic infarction and a subphrenic hematoma. Additionally, he developed signs and symptoms of acute cholecystitis which in turn led to an open cholecystectomy. The gallbladder had a markedly thickened wall due to multiple recent and recanalized thrombi predominantly in subserosal veins. Only a few arteries were occluded by thrombi. A marked vascular proliferation in the subserosal connective tissue mimicking a hemangioma was most likely the result of collateral circulation. There was also a mild acute and chronic inflammatory infiltrate and edema in the lamina propria of the gallbladder. Hyperplasia of interstitial cells of Cajal in the lamina propria and between smooth muscle cells and proliferation of nerve trunks in the subserosal connective tissue adjacent to the thrombosed veins and arteries was also noted. To our knowledge this unique gallbladder thrombotic complication of essential thrombocythemia has not been previously reported.