Diagnosing Kikuchi disease on fine needle aspiration biopsy: a retrospective study of 44 cases diagnosed by cytology and 8 by histopathology.

OBJECTIVE: To study the accuracy of fine needle aspiration (FNA) diagnosis of Kikuchi lymphadenitis (KL). STUDY DESIGN: Retrospective review of all cases of FNA biopsy of lymph nodes in which KL was diagnosed or suggested. False positive cases were studied. Cases of KL diagnosed by histopathology were examined for the false negative rate of FNA diagnosis. RESULTS: Forty-four cases of KL diagnosed or suggested by FNA were found. Five of eight cases were confirmed on lymph node excision. The false positive rate was 37.5%. One case was nonspecific reactive changes. Two cases were proven to be tuberculous lymphadenitis by culture. Eight cases of KL diagnosed by lymph node excisional biopsy had prior FNA. Four were diagnosed as or suspected to be KL. The false negative rate was 50%. CONCLUSION: The overall accuracy of FNA diagnosis of KL was 56.25%. Detailed study offalse positive cases and knowledge of other conditions suggested that overreliance on certain cytologic features and the morphologic erlap between KL and tuberculous lymphadenitis could have been the reasons for the inaccuracies.