DNA flow cytometry of non-Hodgkin's lymphomas: correlation with cytologic grade and clinical relapse.

In this prospective study, we correlated cytological grading and clinical follow-up of non-Hodgkin's lymphomas (NHL) with DNA flow cytometry (FCM) data from fine-needle aspiration biopsy (FNAB) material. FNAB was performed from 34 successive cases of NHL, and the aspirated material was analyzed by DNA FCM. Cytological subtyping and grading were done by modified Working Formulation. Cases were followed up for 2.5 yr, and cytological grading, clinical follow-up, and DNA FCM data were correlated. There were 8 cases of low, 14 intermediate, and 12 high-grade NHL. None of the cases of low-grade NHL showed DNA aneuploidy. Of the 8 DNA aneuploid cases, 5 were of intermediate and 3 were of high-grade NHL. Mean growth fraction (GF) of low-grade, intermediate-grade, and high-grade NHL was 6.1, 9.4, and 19.4, respectively. DNA aneuploidy was statistically significant (P < 0.05) between low- vs. intermediate- and high-grade NHL. Growth fraction was also statistically significant between low- vs. high-grade NHL. Six cases showed clinical recurrence, and one case died within 6 mo of diagnosis, due to widespread involvement of NHL. DNA aneuploidy and mean GF of recurrent and nonrecurrent cases were statistically significant (P < 0.05) irrespective of grading of NHL. DNA aneuploidy and GF are not well-correlated with morphological grading (by the Working Formulation). However, these two criteria are important for assessment of early clinical relapse of NHL.