Ottawa Endometrial Metaplasia in an Albino Rat

Although focal squamous metaplasia of the endometrium is not uncommon in rodents, diffuse squamous metaplasia involving the entire uterus is rarely seen. This paper records a rare example of unilateral stratified squamous metaplasia of the uterine mucosa with keratometra in a virgin rat. Case Report A Sprague-Dawley virgin female was autopsied at the age of 22 months. The animal was one of a control group that had been given 0.5 ml of Mazola oil orally once a week for 17 months. Autopsy findings were mammary fibroadenoma of the right anterior lower abdominal wall, unilateral hematometra and contra-lateral keratometra. Both uterine horns were dilated to 9 mm in diameter. Ex-ternally, the left uterine horn appeared black because of hemorrhagic debris in the lumen. The entire right uterine horn was white and contained considerable white friable cheesy material in its cavity (Fig. 1). Histologically, hemorrhagic debris was seen in the lumen of the left uterine horn. The mucosa was covered by single low columnar epithelium, and no endo-