Macronodular deformity of the spleen

Background and methods: Macronodular splenic deformity without a focal lesi on has rarely been reported. We present three such cases and discuss the po ssible pathomechanism. Results: There was one case of macronodular deformity of unknown cause. In this case, the liver was elongated anteriorly over the dome of the spleen, and the markedly deformed spleen mimicked a round lesion in the left lobe o f the liver. Color Doppler ultrasonography showed the major intra- and peri splenic vessels to be patent. There were two cases of macronodular deformit y associated with extended portal thrombosis. In both cases, portal thrombo sis extended throughout the intrahepatic and extrahepatic portal systems, a nd this portal flow disturbance was presumed to be the cause of the splenic deformity. Conclusion: Although very rare, thrombosis should be sought throughout the portal system when ultrasonography shows a markedly deformed spleen. Marked splenic deformity, especially in cases with an elongated liver, may mimic a liver tumor. A good understanding of its sonographic appearance may help sonographers prevent a hazardous misdiagnosis.