Fine-needle aspiration cytology and flow cytometric immunophenotyping in diagnosis and classification of non-Hodgkin lymphoma in comparison to histopathology.

This prospective study aimed to compare the value of fine needle aspiration (FNA) cytology (FNAC) and flow cytometric immunophenotyping (FCI) with histopatopathology (HP) in the diagnosis and classification of non-Hodgkin lymphoma (NHL). Twenty-nine excised lymph nodes suspected of NHL were evaluated using FNAC, FCI, and HP. Specimens were divided into two equal parts; one for HP and the other for FNAC and FCI. Results were compared in terms of diagnosis (malignant, benign or reactive, and metastatic) and NHL class. With combined FNAC/FCI, 11 (37.9%) cases were diagnosed as NHL, 11 cases (37.9%) as reactive lymph node, six cases (20.6%) as Hodgkin's lymphoma, and one case (3.4%) as metastasis. HP revealed nine cases (31%) of NHL, five cases (17.2%) of reactive lymph nodes and all the diagnosed metastatic and Hodgkin's lymphoma. Considering histology as a gold standard method in diagnosis, the sensitivity, specificity, PPV and NPV of FNAC/FCI in differentiate malignant and benign lesion were 73.9%, 83.3%, 94.4%, and 45.5%, respectively and in differentiate NHL from others were 75%, 93.8%, 90%, and 83.3%, respectively. Cytology and HP in addition to FCI and HP are significantly different from determination of NHL lesions point of view (P = 0.001 and P < 0.0001, respectively). However, FCI can be considered as an adjunctive method for Cytology especially because Cytology is not competent enough to differentiate between benign lesions and Lymphoma. Additionally, FCI is shown to be an accurate method in classifying NHL.