Abstract
A woman in her 40s presented with an upper abdominal tumor that was detected on abdominal ultrasound during a complete medical checkup. On abdominal ultrasound, a 5-cm-diameter tumor was observed between the lesser curvature of the stomach and the lateral segment of the liver ; it was slightly hypoechoic relative to the spleen. On abdominal contrast-enhanced CT and plain MRI, the tumor had an almost uniform density and intensity, with similar enhancement to the spleen. An accessory spleen was suspected, but because the possibility of malignant lymphoma, gastrointestinal stromal tumor (GIST), and other conditions could not be ruled out, the tumor was surgically resected. The tumor, which was hard and 5 cm in diameter, was surrounded by an enlarged lymph node, with which it formed a single mass. Histopathological tests revealed a follicular dendritic cell tumor accompanied by Castleman's disease. We report the present case with reference to the literature because this condition is extremely rare.
