A morphometrical analysis of minute depressed adenomas in familial polyposis coli

In a morphometrical study of minute adenomas in familial polyposis coli (FPC), ranging from 0.8 mm to 1.5 mm in diameter, five parameters of depressed adenomas were compared with those of ordinary polypoid adenomas. The density of glands (DG), an index of structural atypia, and the nuclear-cytoplasmic (N/C) ratio, an index of cellular atypia, were higher in depressed adenomas than in polypoid adenomas (74.8% vs 66.8% and 37.8% vs 32.7%, respectively). The cell area (C-area) of depressed adenomas was less than that of polypoid adenomas (107.3 microns 2 vs 121.1 microns 2), but there was no significant difference in values for the nuclear area (N-area) in the two types (40.0 microns 2 vs 39.2 microns 2). The higher N/C ratio of depressed adenomas was, therefore, not caused by enlargement of the nuclei but by reduction of the cell size. In addition, values of the sphericity of nuclei (SN) (3.14 vs 3.65) indicated rounder nuclei in depressed adenomas than in ordinary ones. The higher DG and N/C ratio of the depressed adenomas indicates their higher grade of atypia than that of ordinary polypoid adenomas.