Enterobius vermicularis

Comments:
Pinworms (Enterobius vermicularis) were an incidental finding in this middle-aged woman who underwent hysterectomy and staging procedure for endometrial adenocarcinoma. The lateral "spines" (actually longitudinal blade-like ridges running the length of the worm) are identifying features of the pinworm.

Image courtesy of: Ed Uthman, Houston, Texas.