Histiocytic necrotizing lymphadenitis diagnosed by conventional cytology and liquid based cytology

Histiocytic necrotizing lymphadenitis (HNL; Kikuchi-Fujimoto disease) is a rare benign disorder. The diagnosis of HNL is established on recognizing the characteristic histologic findings from biopsy of the enlarged lymph nodes. Though diagnosis of HNL by fine-needle aspiration (FNA) was reported, the characteristic fine-needle aspiration cytologic features with conventional cytology and a liquid based cytology test (LCT) have not been well documented. In this study, 42 cases of suspicious necrotic lymph nodes were subjected to cytology and biopsy diagnosis. The lymph nodes were aspirated using a 10 mL disposable syringe with the percutaneous ultrasound guided. Samples were used for conventional cytology and LCT. Among 42 cases of suspicious necrotic lymph nodes, 37 of cases were histologically confirmed as HNL; 3 of cases were hyperplasia of lymphoid tissue; 1 case was tuberculosis of lymph node, and 1 case was classical Hodgkin lymphoma (nodular sclerosis type). 31 out of 37 (83.8%) cases of HNL were diagnosed by conventional cytology, 33 out of 37 (89.2%) were diagnosed by LCT. Our results indicate that no significant difference on accuracy rate between conventional cytology and LCT, but LCT has its advantages in the diagnosis of HNL.