Castleman病に関連した後腹膜の濾胞性樹状細胞肉腫の1例

A case of retroperitoneal follicular dendritic cell sarcoma associated with Castlemanʼs disease

濾胞性樹状細胞（follicular dendritic cell：FDC）に由来するまれな腫瘍として濾胞性樹状細胞腫・肉腫が知られており，Castleman病との関連が報告されている^1）。今回我々は，後腹膜に発生したCastleman病に関連した濾胞性樹状細胞肉腫について，その病理学的所見をふまえた画像所見の特徴を検討し，報告する。

A man in his 60s with an approximately 5cm mass near the pancreatic head. CT showed arterial hyperenhancement and late washout on the ventral part（VP）and delayed enhancement on the dorsal part（DP）in the mass. On MRI, T2 weighted imaging and ADC map showed biphasic signal intensity between VP and DP. Pathologically, VP was diagnosed as hyaline-vascular Castleman disease and DP as follicular dendritic cell sarcoma. Focusing on the intratumoral biphasic nature may help the diagnosis of this rare tumor.