Fine-needle aspiration cytology of Castleman disease: case report with review of the literature.

Organs involved by Castleman disease (CD) may be investigated by fine-needle aspiration cytology. No specific cytomorphological criteria are currently described for a definitive diagnosis. The cytological features of three fine-needle aspirations from three different lymph nodes of a patient with histologically confirmed CD of the hyaline-vascular type are herein reported, with a review of the literature. The fine-needle aspirations showed branching capillaries associated with fragments of germinal center. Review of the literature yielded 12 other case reports with over half describing similar findings. Because branching hyalinized small blood vessels penetrating follicular germinal center are characteristic of CD of the hyaline-vascular type on histology, this finding in fine-needle aspirates should raise that diagnostic possibility.