Comparison of the DNA content in low and high grade non-Hodgkin lymphomas.

In the fine needle aspiration biopsy (FNAB) of lymph nodes, the deliniation of low grade non-Hodgkin lymphoma (NHL) from high grade NHL by means of morphology may be difficult. To gain additional diagnostically helpful criteria, cytophotometric analysis of the DNA content was applied. 117 specimens of NHL were examined, including 51 cases of low grade NHL (14 centroblastic-centrocytic, 9 centrocytic, 14 lymphoplasmocytoid immnocytomas and 14 chronic Iymphocytic leukemias) and 66 cases of high grade NHL (15 centroblastic, 18 immunoblastic, 7 Burkitt and 26 lymphoblastic). The smears were stained with Feulgen and were evaluated by image analysis (CAS 200, Becton- Dickinson). The 5 c exceeding rate differed significantly (p = 0.0081) between low- and hig-grade NHL. In the group of low grade NHL, clearly aneuploid cases were not found (Auer type I 32%, type II 62%, type III 6% of cases). The high grade NHL's showed histograms Auer type II (10% of cases), type III (62% of cases) as well as clearly aneuploid type IV (28% of cases). In summary, image cytophotometry can be used along side morphology to differentiate between low and high grade lymphomas in morphologically difficult cases.