MORPHOMETRIC ANALYSIS OF BOVINE LYMPHOMAS CLASSIFIED ACCORDING TO THENATIONAL-CANCER-INSTITUTE WORKING FORMULATION

The National Cancer Institute Working Formulation (NCI-WF) for the sub jective classification of human non-Hodgkin's lymphoma is readily appl icable to the classification of bovine lymphomas. Forty-nine cases of bovine lymphoma were analysed morphometrically to see if nuclear size and cleavage were distributed continuously or discretely between diffe rent NCI-WF tumour cell types. The mean nuclear area (+/-standard erro r of the mean, SE) was significantly greater (P<10(-6)) in cells from the different types of diffuse large cell lymphoma than in cells from the different types of small-cell lymphoma (42.91+/-1.21 mu m(2) vs 19 .33+/-1.08 mu m(2), respectively); there was no overlap between the tw o groups. The mean nuclear area (+/- SE) of cells from diffuse large-c ell lymphomas was significantly greater (P<10(-4)) than that of cells from small non-cleaved lymphomas (42:74+/-1.72 mu m(2) vs 27.54+/-1.08 mu m(2), respectively), and there was again no overlap between the tw o groups; these two cell types are difficult to distinguish by any cri teria other than size. Additionally, the cell-to-cell variability in n uclear area within a given tumour was significantly greater (P<0.001) for the diffuse large-cell type than for the small non-cleaved cell ty pe. The mean nuclear form factor (+/- SE) and mean nuclear contour ind ices (+/- SE) of the diffuse large cleaved cell type (0.53 +/- 0.02 an d 5.08 +/- 0.11, respectively) were significantly different (P<0.01 to 10(-6)) from the same parameters in the diffuse large-cell type (0.82 +/- 0.01 and 3.94 +/- 0.04, respectively). Some of the major criteria of the NCI-WF used subjectively to discriminate between bovine lympho ma cell types were supported by morphometric measurements. The magnitu de of the differences in nuclear morphological characteristics between bovine lymphoma cell types was such that there was no overlap. (C) 19 98 W.B. Saunders Company Limited.