Angioimmunoblastic lymphadenopathy--a malignant disease due to DNA aneuploidy.

Angioimmunoblastic lymphadenopathy (AIL) was considered by most authors in the 1970s as a non-malignant disease. However, it is widely accepted that many AIL cases would now be categorised as T-cell lymphomas of the AIL type. DNA measurements were performed on imprint smears from lymph nodes of 10 AIL patients to obtain further evidence for the malignancy of this disease. The 5c Exceeding Events (5cEE), representing the number of cells with a DNA content greater than 5c, excluding cells with 8c, 16c or 32c (+/- 12.5%), were taken as an index for aneuploid cells. 5cEE greater than or equal to 3 was considered to be evidence for aneuploidy and thus for malignancy. According to this definition of aneuploidy, malignancy was assumed in 9 cases out of 10. No aneuploid cells (5cEE = 0) were found in four patients with lymphadenitis.