Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

The uterus has thick walls and a small, flat, triangular-shaped cavity. Its apex is directed downwardand forms the internal os which opens into the cervical canal. The cervical canal narrows at its lowerend and forms the external os opening into the vagina. The mucosa of the vaginal wall is contiguouswith the mucosa of the cervix. A circular recess around the cervix at its junction with the vagina iscalled the fornix. It is divided into four fornices or parts: anterior, posterior, and two lateral. Thefallopian tubes join the uterine cavity at the upper, outer angles. A generous blood supply is receivedby the uterus from the uterine arteries which are branches of the internal iliac arteries. Eightligaments which hold the uterus in place but allow considerable movement are two broad ligaments,two uterosacral ligaments, the posterior ligament, the anterior ligament, and two round ligaments.Parametrium, connective tissue which surrounds the uterus, separates the cervix from the bladderand extends between the two serosal layers of the broad ligaments as well as to and over the pelvicwalls.RegionalLymph NodesThe regional lymph nodes for both the corpus and the cervix uteri are:Pelvic Nodes:ParacervicalParametrialCommon iliacInternal iliac (hypogastric, including obturator)External iliacSacral (lateral, presacral, promontory (Gerota's), uterosacral)Aortic (para-, peri-, lateral)--regional for corpus uteri onlyThe major lymphatic trunk is the utero-ovarian (infundibulo-pelvic), which drains into the iliac andsacral nodes.Malignant TumorsThe histologic types of cancer arising in the uterus are:• Adenocarcinoma arising in the glandular epithelium of the endometrium and of theupper two-thirds of the cervical canal• Leiomyosarcoma arising in the smooth muscle of the myometrium• Adenosquamous carcinoma arising at the squamous columnar junction• Squamous cell carcinoma arising in the lower one-third of the cervical canal and thelip of the cervix, and often extending into the vagina. The majority of theneoplasms arising in the cervix will arise in the lower one-third. These will bechiefly in situ, i.e., there will be no stromal invasion. Lesions with stromal invasionof 3 mm or less may be described as micro-invasive.° Endometrial stromal sarcoma277