Leiomyoma.

Leiomyoma.
Leiomyomas generally occur as a solitary growth in the wall of the uterus. Because of their firmness and smoothness that can be confused with an abscess, on palpation. For orientation, notice an inactive ovary at the bottom right of the image. Also visible are numerous involuted caruncles in the opened lumen of the uterus, indicating that this was the uterus of a pluriparous cow. This was an incidental slaughterhouse specimen.

Drost M (1980)