FNAC of Lymph Node - A Valuable Clue to Diagnosis of Toxoplasma Lymphadenitis

Abstract

Background: Fine needle aspiration cytology (FNAC) is now a days the initial investigation in most cases of superficial lymphadenopathy. In clinical practice both clinicians and cytopathologists are not commonly suspecting of Toxoplasma lymphadenitis (TL), though it may constitute a significant proportion of unexplained lymphadenitis. Careful cognizance of cytological findings can give valuable clue to the diagnosis of toxoplasmosis which can be confirmed by serological evidence.

Methods: This cross-sectional study was conducted in Department of Histopathology of Armed Forces Institute of Pathology (AFIP), Bangladesh from 01 July 2017 to 31 March 2018. FNAC smears of the patients with lymphadenopathy who reported for FNAC were examined and suspicion of toxoplasmosis was made on coexistence of abundance of ‘tingible body macrophages’ (TBM) and follicular center cells (FCC), small collections of epithelioid histiocytes and absence of necrosis and/or more than occasional giant cells. Serum enzyme linked immunosorbent sorbent assay (ELISA) for Toxoplasma IgM and IgG antibody was then performed in all cases that deemed suspicious for toxoplasmosis for confirmation of the diagnosis.

Results: Total 925 patients were examined by FNAC of lymph node. Among them 574 were categorized as reactive hyperplasia (RH). Thirty two patients (5.74%) of RH were suspected as TL and included in the study. Serum ELISA confirmed toxoplasmosis in 22 (68.75%, twelve male and ten female) of these 32 cases. One among the positive cases revealed bradyzoites of Toxoplasma in the smear. The age of the patients diagnosed finally as TL spanned between 5 to 47 years (mean 28.59±11.51 years) though most frequent age group was 26 Yr to 35 Yr (7 cases- 31.8%).

Conclusion: A high index of suspicion of TL can be made on careful study of smears of FNAC of enlarged lymph node, diagnosis of which can then be confirmed by ELISA.

Birdem Med J 2018; 8(2): 103-107