Kikuchi lymphadenitis cytology, histopathology correlation and immunohistochemical study

ABSTRACT

Kikuchi's lymphadenitis [KL], a benign and unusual self-limiting histiocytic necrotizing lymphadenitis of unknown origin, should be included in the differential diagnosis of lymphadenopathy and fever of unknown cause. Lymph node fine needle aspiration cytology [FNAC] is valuable in solving the diagnostic problems of clinical adenopathy. The Present research is aiming to study the correlation between fine needle aspiration cytology [FNAC] versus histopathology in diagnosing KL, studying the types of cells and the origin of plasmacytoid cells and we are also aiming to study the pathogenesis of apoptosis in this type of necrotizing lymphadenitis. Four cases of Kikuchi's lymphadenitis were received at Pathology Department, Al-Baraha Hospital, Ministry of Health, and Dubai, United Arab Emirates. Patient's clinical data were collected from their files. Fine-needle aspiration cytology from the four patients as well as histological sections from formalin fixed, paraffin blocks were studied. Immunohistochemistry was applied using monoclonal antibodies for Granzyme-B, CD68, CD20, CD3, CD8 andCD4; in addition we used also monoclonal mouse antihu-man bcl2 and P53 protein for evaluation of apoptotic activity. Four cases of KD were received at pathology department, AL Baraha hospital, Dubai. Three cases were female's average age 24.6 and one 17 Years old boy. All cases were Indian. Fine needle aspiration cytology [FNAC] was performed for every case. PAP smears, H and E sections and immnuohistochemistry [CD3, CD20, CD4, CD68, Granenzyme-B, BCL2 and P53] were done for every case. Out results showed FNAC diagnosis depend mainly on the detection of histocytes with peripheral crescent nuclei and phagocytosis of apoptotic debris. Immunohistochemical study revealed that plasmacytoid cells are histocytic in origin, the most common type of lymphocytes are CD8+T cells. Pathogenesis of apoptosis in this disease is mainly due to Granenzyme B secreted by T-killer cells and the genetic apoptotic pathology alteration [BCL2, P53] has no rule in its parthenogenesis. Fine needle aspiration cytology is a helpful and conclusive technique for the diagnosis of typically presented cases of Kikuchi lymphadenitis. The histiocytes and plasmacytoid cells are of the same origin. The main lymphoid cellular infiltrate is by the cytotoxic T lymphocyte which releases Granzyme-B protein [effector] that induces apoptosis in target cells as a result of an acquired stimulus and apoptotic genes have no role in induction of apoptosis in Kikuchi lymphadenitis