Assessment of uterine wall thickness and position of the vascular plexus in the deep myometrium: implications for the measurement of depth of myometrial invasion of endometrial carcinomas.
Accurate discrimination between FIGO stages IB and IC endometrial carcinomas has important prognostic and therapeutic implications, but depth of invasion as a percentage of myometrial thickness can be difficult to ascertain. In such cases, pathologists often presume that infiltration that reaches the arcuate vascular plexus (AVP) in the myometrium indicates >50% myoinvasion. The further assumption is sometimes made that the anterior and posterior uterine walls are of the same thickness. To our knowledge, neither supposition is based on published data. We performed a prospective study of myometrial thickness and the position of the AVP in 50 normal uteruses from patients aged 27 to 84 years. Myometrial thickness varied inversely with age (p < 0.0001); however, anterior and posterior wall myometrial thickness did not differ significantly in the cohort as a whole (p = 0.059) and in individual cases was highly correlated (p < 0.0001). The position of the AVP was variable. On average, its inner limit was situated at a depth of 47.3% of the thickness of the myometrium in both uterine walls, but the position varied between individuals and sometimes differed considerably between the anterior and posterior walls of the same uterus. The position of the AVP did not differ significantly with age. We conclude that carcinomatous infiltration well into or through the AVP usually signifies >50% myoinvasion; however, if infiltration barely extends into the AVP, the depth of invasion should be calculated with reference to the thickness of the myometrium in the opposite uterine wall.
Williams
Jonathan W
JW
Department of Histopathology, Gloucestershire Royal Hospital, Gloucester, United Kingdom.
Hirschowitz
Lynn
L
D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016889:Endometrial Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008875:Middle Aged; D009215:Myometrium / Q000098:blood supply* / Q000473:pathology*; D009361:Neoplasm Invasiveness; D011446:Prospective Studies