Fine-needle aspiration cytology of ganglion cysts.

Ganglion cyst is a relatively common lesion resulting from mucoid, cystic degeneration of soft tissues adjacent to a joint space. Aspiration of cyst contents has been increasingly advocated as a diagnostic and, in some instances, therapeutic modality. We report the fine-needle aspiration cytologic (FNAC) findings from seven cases of ganglion cyst. These include the aspiration of thick, gelatinous fluid and a smear comprised of rare histiocytes embedded in a mucoid matrix. Although these findings are nonspecific, we believe that in the appropriate clinical setting, the diagnosis of ganglion cyst can be made with confidence by FNA.