Comparative cytophotometric analysis of reactive lymphoid hyperplasia and low malignant non-Hodgkin lymphoma

In fine needle aspiration biopsy (FNAB) of lymph nodes, differential diagnosis between reactive lymphoid hyperplasia (RLH) and low grade non-Hodgkin lymphoma (NHL) may be sometimes difficult. Cytophotometric analysis of DNA content using image analysis has found practical application in the determination of malignancy in different tumours. In this study, image cytometry was applied to compare the ploidy status of the above mentioned lesions to obtain diagnostically helpful information. Thirty smears of histologically proven low grade NHL (10 follicular lymphomas of centroblastic-centrocytic type, 10 lympho-plasmocytoid immunocytomas, 10 chronic lymphocytic leukemias) and 15 smears of RLH were stained with Feulgen and examined by image analysis (CAS 200, Becton Dickinson). The 5c exceeding rate was determined according to the Boecking's definition of aneuploidy. Concerning the histogram types the Auer classification was used. The aneuploidy was found in 4/10 follicular lymphomas and 4/10 lymphoplasmocytoid immunocytomas. All chronic lymphocytic leukemias were diploid. In none RLH a 5c exceeding rate was found. The results verify the value of image cytophotometry as a helpful method in some diagnostically difficult cases.