[An abdominal follicular dendritic cell tumor in Castleman's disease].

A 57-year-old man was referred to our hospital because of elevated ALP. CT and MRI scans together with abdominal angiography showed multiple masses in his abdomen and portal vein obstruction. A diagnostic laparoscopic examination revealed a tumor of 3 cm x 3 cm near the portal vein and para-aortic lymphadenopathy. Histopathological examination of the tumor showed abnormal follicles with poorly formed germinal centers, scattered large spindle cells with proliferation of small lymphocytes, and hypervascular interfollicular tissue. The spindle cells were positive for follicular dendritic cell markers CD21, CD35, and epithelial membrane antigen. The diagnosis was made of a follicular dendritic cell (FDC) tumor in Castleman's disease (CD) of the hyaline-vascular type. Although the portal vein was obstructed by the FDC tumor, blood flow to the liver was retained by collateral vein. The patient did not show any response to four courses of CHOP therapy and died of obstructive jaundice, biliary tract infection and sepsis. So far, 17 cases of FDC tumor complicating CD have been reported, with a poor prognosis in all cases.