Table 2.

Histometry data: Number of pre-neoplastic lesions (PNLs) per slice defined as: ‘acidophilic’, ‘mixed’ or ‘clear cell’ nodules

PNL	Control (N = 8)	Experimental (N = 9)
Acidophilic cells	7.87 ± 14.31a	2.11 ± 5.97**
Mixed	28.37 ± 23.86	11.00 ± 14.26
Clear cells	1.50 ± 2.390	1.88 ± 2.571

Experimental rats were treated with 10% Comfrey extract, po.

^aValues represent mean ± standard deviation.

**Mann–Whitney test, P = 0.05 (U = 56.0).

This cell behavior follows the sequence: clear/mixed/acidophilic/basophilic nodules, according to their aggressiveness (see text).