High incidence of chromophobe pituitary adenoma-like lesions in an inbred Sprague-Dawley breeding rat colony.

A high incidence is recorded of pituitary chromophobe adenomalike lesions in an inbred Sprague-Dawley line of laboratory rats. 80 % of the males and 5 % of the females had the lesion at an age of about 340 days. The patho-anatomical features are described and the significance of the lesion is shortly discussed.