Uterus : Surgical Pathology Dissection

Uterus

The uterus is removed for a wide variety of reasons. Common indications for hysterectomy include uterine prolapse, leiomyomas, endometrial hyperplasia, cervical cancer, and endometrial cancer. Given the diverse nature of these pro-cesses and the variation in the appearance of the uterus due to the hormonal environment, it is important to know both the clinical indica-tion for the surgery and the patient’s reproduc-tive status when evaluating a hysterectomy specimen.

The uterus is traditionally divided into two components: (1) the uterine corpus and (2) the uterine cervix. The uterine corpus (or body) ex-tends from the superiorly located fundus to the point of maximal narrowing which corresponds to the location of the internal os. The right and left cornual regions are located superolaterally, at the insertion of the fallopian tubes. The inferior 1 to 2 cm of the corpus is referred to as the isthmus or lower uterine segment (LUS). This region is a ‘‘bridge’’ between the cervix and the uterus and demonstrates a gradual transition from endocer-vical to endometrial mucosa. The cervix encom-passes the lower portion of the uterus, beginning at the internal os. The cervix is composed of an inner endocervical canal lined by columnar epi-thelium and a rounded outer ectocervix covered by squamous epithelium. The location of the squamocolumnar junction moves in and out of the cervical canal with age and parity. It is within this region that most intraepithelial lesions arise. Although the exact limits of this region are not visible grossly, the term ‘‘transformation zone’’ encompasses this entire transition area including the squamocolumnar junction.

This section provides an approach to the eval-uation of hysterectomy specimens in four cate-gories: (1) hysterectomies for nonmalignant disease, (2) hysterectomies for endometrial can-cer, (3) radical hysterectomies for cervical cancer, and (4) pelvic exenterations with vaginectomies for vaginal cancer or recurrent cervical cancer.