Clinical diagnosis
Case 224
【Progress】
She returned to the original gynecologic clinic with a diagnostic MRI report made by our radiologist.
【Discussion】
Uterus is composed of four layers; endometrium, junctional zone, myometrium, and serosa. Of these, the former three components are recognized on pelvic MRI with T2 WI. Junctional zone is a compressed muscle layer with little extracellular fluid space (1). Uterine contraction begins from junctional zone. It functions to help sperm to move to ovarian duct by contracting uterus. Junctional zone also plays a role of barrier for endometrium not to invade myometrium during menstruation cycle (1).
Adenomyosis is a disease that endometrium invades to myometrium via junctional zone. It occurs most at age of forties and fifties after uterine curettage, although true mechanism causing adenomyosis is not yet to be clarified (2).
Adenomyosis is termed as invasion and proliferation of endometrial cells to myometrium of the uterus, while endometriosis is termed as those of endometrial cells to outside uterus: ovary, intraperitoneal cavity. Adenomyosis and endometriosis changes its size dependent on menstruation cycle. Namely, adenomyosis and endometriosis grows by stimulation of estrogen. Then, it grows as long as menstruation preserves. Adenomyosis, endometriosis and myoma decrease in size after menopause. As treatment, nonsteroid anti-inflammatory drugs, hormone therapy, transcatheter arterial embolization and endometrial ablation are listed.
Patients with adenomyosis suffer from heavy and prolonged menstruation bleeding, lumbago, abdominal chronic pain. Pelvic MRI is one of the diagnostic modalities for adenomyosis. T2WI MRI show a uterine mass including a number of small cysts with high signal intensity (3-7). Some of cysts including bloody content are shown high signal intensity on T1WIMRI. Small cysts arise from gland of endometrium. Then, it is easy to diagnose adenomyosis when typical findings appear on MRI. However, it can be difficult when uterine mass has not small cystic lesion in the mass. In this situation, it is documented that thickness of junctional zone of 7 mm or less indicates within normal limits, junctional zone of 8 to 12 mm thickness indicates focal adenomyosis, junctional zone of 13mm or more indicates diffuse adenomyosis (3-7).
It is clinically important to differentiate endometrial cancer from adenomyosis owing no small cysts. ADC values can be useful because it is reported ADC values of endometrial cancer are approximately 0.8 to 1.0 while those of adenomyosis and myoma are approximately 1.2 to 1.4 (8).
【Summary】
We present a fifty one-year-old female suspicious of adenomyosis of the uterus. The large uterine mass including a number of small cysts were shown on T2WIMRI. Several cysts of these were shown as high signal intensity on fat suppression T1WIMRI, indicating bloody component. These findings were compatible with adenomyosis of the uterus. Adenomyosis is a disease that endometrium invades to myometrium via junctional zone. It is borne in mind that adenomyosis is a disease that endometrium invades to myometrium via junctional zone. Thickness of junctional zone of 7 mm or less indicates within normal limits, junctional zone of 8 to 12 mm thickness indicates focal adenomyosis, junctional zone of 13mm or more indicates diffuse adenomyosis. ADC values of endometrial cancer are approximately 0.8 to 1.0 while those of adenomyosis and myoma are approximately 1.2 to 1.4.
【References】
1.Fusi L, et al. The uterine junctional zone. Best Pract Res Clin Obstet Gynaecol 2006; 20:479–491
2.Matalliotakis, I, et al. "Adenomyosis". Obstetrics and Gynecology Clinics of North America. 2003; 30 : 63–82,
3.Scoutt LM, et al. Junctional zone of the uterus: correlation of MR imaging and histologic examination of hysterectomy specimens. Radiology 1991; 179:403 –407
4.McCarthy S, et al. Uterine junctional zone: MR study of water content and relaxation properties. Radiology 1989; 171:241–243
5.Maubon A, et al. Uterine junctional zone at magnetic resonance imaging: a predictor of in vitro fertilization implantation failure. J. Obstet. Gynaecol. Res. 2010;36 : 611-8
6.Novellas S, et al. MRI Characteristics of the Uterine Junctional Zone: From Normal to the Diagnosis of Adenomyosis. American Journal of Roentgenology. 2011;196: 1206-1213.
7.Takeuchi, M, et al. Adenomyosis: usual and unusual imaging manifestations, pitfalls, and problem-solving MR imaging techniques. Radiographics 2011;31(1):99-115.
8.Deng L,et al. Diffusion-weighted imaging (DWI) of adenomyosis and fibroids of the uterus. 2014 Jun;39(3):562-9
2021.3.17