Two Spontaneous Uterine Tumors in a Rabbit: An Hormonal Investigation

Abstract

There have been recorded in the literature between 90 and 100 spontaneous tumors in the rabbit, of which 42 were located in the uterus. The present report of two spontaneous uterine neoplasms in a female rabbit brings this latter number to 43. The literature has been reviewed and references are given by Cutler (1), Heiman (2), and, most recently, by Orr and Polson (3). The uterine tumors here described were observed June 9, 1937, in a mature female black and white rabbit between eight months and one year old, weighing 2520 gm. The past history of the rabbit was not obtainable. The animal was being used for immunological sera studies, and as it was thought to be pregnant, since two masses could be felt in its abdomen, it was discarded for that purpose and operated upon to obtain some fetal tissue. Upon opening the abdomen two tumors were encountered. One was located at the bifurcation of the uterine horns, extending more to the right side than to the left. It was of a deep purplish color with dilated veins on its surface; it measured 5 × 3 × 3 cm. and on section showed extreme proliferation of the endometrium, which completely obliterated the lumen. The second tumor was at the mid-point of the left horn and measured about 2 × 2 × 2 cm. When the uterine wall over this tumor was cut through, an endometrial mass, attached to the wall of the horn by a sessile base, extruded itself. On gross examination both ovaries showed fresh corpora lutea. No metastatic nodules were present in the retroperitoneal lymph nodes and lungs, nor was any abdominal organ invaded by neoplasm. Unfortunately neither adrenal glands, breasts, nor the hypophysis were removed for microscopic study. Grossly there was no evidence of pregnancy in either uterine horn.