Adenomyosis is a benign uterine condition characterized by invasion of endometrial glands and stroma into the myometrium. It occurs in 20-35% of reproductive-age women; however, histopathological prevalence can reach 70% in hysterectomy specimens. With development of diagnostic criteria, imaging diagnosis rates have increased. Clinically characterized by dysmenorrhea (painful menstruation), menorrhagia (heavy bleeding), and uterine enlargement (globular uterus). MRI is the gold standard for diagnosis — junctional zone (JZ) thickening >12 mm is pathognomonic. On US, heterogeneous myometrium, myometrial cysts, Venetian blind shadowing, and asymmetric myometrial thickening are diagnostic clues. Diffuse and focal (adenomyoma) forms exist. Coexistence with leiomyoma is common and differentiation can be difficult. Association with endometriosis is also frequent. Its relationship with infertility has been proven — reduces implantation success. Treatment options include medical (hormonal), interventional (UAE), and surgical (hysterectomy — definitive).
Age Range
35-55
Peak Age
45
Gender
Female predominant
Prevalence
Very Common
Adenomyosis is the invasion of endometrial basal layer (glands + stroma) into the myometrium along the endometrial-myometrial junction (junctional zone). The normal junctional zone (JZ) consists of compact smooth muscle and functions as a barrier between endometrium and outer myometrium — this barrier is disrupted in adenomyosis. Ectopic endometrial glands within the myometrium respond to hormonal stimulation each menstrual cycle → cyclic bleeding, inflammation, and fibrosis develop. These reactive changes lead to myometrial hypertrophy (smooth muscle hyperplasia) and fibrosis → diffuse uterine enlargement (globular form). Pathophysiological basis of imaging findings: (1) JZ thickening — ectopic tissue and reactive smooth muscle hyperplasia expand the junctional zone → T2 hypointense thickening on MRI (smooth muscle = short T2), (2) Myometrial cysts — cystic dilation of ectopic endometrial glands → T2 hyperintense punctate foci (free fluid = long T2), T1 hyperintensity (hemorrhagic content/old blood), (3) Heterogeneous myometrium — ectopic glands, stroma, fibrosis, and smooth muscle hyperplasia create mixed tissue composition → heterogeneous echo pattern on US, (4) Venetian blind shadowing — myometrial fibrosis and smooth muscle hyperplasia attenuate ultrasound waves at different intensities → linear radial shadowing artifacts. Increased subendometrial vascularity (endometrial vascular remodeling) explains menorrhagia pathophysiology. Infertility mechanism: JZ dysfunction impairs uterine peristalsis → sperm transport and embryo implantation are adversely affected.
Junctional zone thickness exceeding 12 mm on T2W is a pathognomonic criterion for adenomyosis. Diagnosis is confirmed when small T2 hyperintense punctate foci (myometrial cysts = ectopic endometrial glands) accompany within thickened hypointense JZ or diffuse myometrium. Normal JZ thickness is 5-8 mm; 8-12 mm is the gray zone (diagnostic if JZ/myometrium ratio >40%). This combination is critical for differentiation from leiomyoma — JZ thickening does not occur in leiomyoma and myometrial cysts are not seen.
Heterogeneous echo pattern in myometrium — mixture of hypoechoic and hyperechoic areas, normal myometrial homogeneity lost. Myometrial cysts: 1-7 mm anechoic/hypoechoic small foci scattered within myometrium. Venetian blind shadowing: linear shadowing artifacts extending radially from myometrium (fan-shaped shadowing). Asymmetric myometrial thickening: anterior or posterior myometrial wall markedly thickened. Subendometrial striations (hyperechoic linear echogenicity increase). Globular uterine enlargement. No pseudocapsule — borders are ill-defined/diffuse unlike leiomyoma.
Report Sentence
Diffuse heterogeneous echo texture in the uterine myometrium with asymmetric myometrial thickening up to ___ mm, myometrial cysts, and radial shadowing artifacts (Venetian blind shadowing) are seen, consistent with adenomyosis.
Increased vascularity in subendometrial region on Doppler — dense vascular flow along endometrial-myometrial junction. Vascularity in affected area is more prominent compared to normal myometrium. Translesional vascularity (vessels extending through adenomyotic area) may be seen. This vascularity pattern differs from peripheral circumferential pattern of leiomyoma — vessels are diffuse and disorganized in adenomyosis, regular along pseudocapsule in leiomyoma.
Report Sentence
Diffusely increased vascularity in the subendometrial region and translesional vascular structures are observed on color Doppler, consistent with adenomyosis.
Junctional zone (JZ) thickening >12 mm on T2W — pathognomonic criterion for adenomyosis. JZ is seen as a T2 hypointense structure (compact smooth muscle). Small hyperintense punctate foci within thickened JZ or diffuse myometrium — cystic dilation of ectopic endometrial glands. T1 hyperintense foci indicate hemorrhagic content (old blood = methemoglobin). In diffuse form, entire myometrium is involved; in focal form (adenomyoma), localized area is affected. JZ/myometrium ratio >40% is a reliable alternative criterion. Asymmetric myometrial thickening (anterior or posterior wall) is common.
Report Sentence
Junctional zone thickness measures ___ mm on T2W (>12 mm) with small hyperintense punctate foci in the myometrium, consistent with adenomyosis.
Small hyperintense foci within myometrium on T1W — reflecting hemorrhagic content (old blood, methemoglobin) in ectopic endometrial glands. These foci may show variable signal on T2 (depending on hemorrhage stage). Hyperintensity is preserved on fat-suppressed sequences → confirming blood, not fat. T1 hyperintense foci are highly specific for adenomyosis — not seen in leiomyoma (unless degeneration).
Report Sentence
Small hyperintense foci within the myometrium are seen on T1W with preserved signal on fat-suppressed sequence, corresponding to hemorrhagic endometrial islands; consistent with adenomyosis.
Mild diffusion restriction in adenomyotic myometrium on DWI — ADC values are mildly lower compared to normal myometrium. No marked restriction (different from endometrial carcinoma). Hemorrhagic foci may show T2 shine-through effect on DWI. DWI is not a primary sequence for adenomyosis diagnosis but helpful in differentiating focal adenomyoma from malignant lesions.
Report Sentence
Mild diffusion restriction is observed in adenomyotic myometrium on DWI/ADC map; no marked restriction consistent with malignant lesion detected.
Criteria
Widespread myometrial involvement, JZ diffusely thickened, heterogeneous myometrium, globular uterus
Distinct Features
Most common form (70%). Uterus symmetrically or asymmetrically enlarged. Myometrial cysts widespread. Venetian blind shadowing prominent on US. Hysterectomy is definitive treatment — fertility-preserving surgery limited.
Criteria
Localized myometrial area involved, well-defined but non-encapsulated focal lesion
Distinct Features
Form most commonly confused with leiomyoma. T2 hypointense mass — but no pseudocapsule, blurry borders, myometrial cysts within. Surgical enucleation difficult (no cleavage plane). MRI characterization critical.
Criteria
Large cystic cavity (>1 cm) within myometrium, prominent dilation of ectopic endometrial glands
Distinct Features
Rare variant. Presents with severe dysmenorrhea in young women. Large hyperintense cystic area on T2, hemorrhagic content on T1 (hyperintense). May be confused with myometrial cyst or endometrioma. Cystic lesion within myometrium on US.
Distinguishing Feature
Leiomyoma shows well-defined round mass, distinct pseudocapsule (T2 hyperintense ring), homogeneous T2 hypointensity, no myometrial cysts, no JZ thickening. Adenomyosis shows ill-defined borders, no pseudocapsule, JZ thickening >12 mm, T2 hyperintense myometrial cysts, T1 hyperintense hemorrhagic foci.
Distinguishing Feature
Endometrial carcinoma shows mass originating from endometrial cavity, marked diffusion restriction (low ADC), myometrial invasion (JZ disruption), irregular enhancement. Adenomyosis shows thickened but not invaded JZ, mild DWI restriction, myometrial cysts (absent in carcinoma), normal endometrial cavity.
Distinguishing Feature
Endometrial stromal sarcoma shows invasion of myometrium and vascular structures (myometrial worm-like extension), heterogeneous intermediate-high T2 signal, marked DWI restriction, venous invasion (extension to IVC). Adenomyosis shows no invasive growth, no vascular involvement, JZ thickening smooth and symmetric, benign appearance.
Urgency
routineManagement
medicalBiopsy
Not NeededFollow-up
6-monthAdenomyosis is a chronic, hormone-dependent disease. Symptom severity is proportional to extent of involvement. First-line treatment is hormonal therapy: oral contraceptives, levonorgestrel IUD (Mirena), GnRH agonists (temporary menopause induction). Definitive treatment is hysterectomy — indicated in severely symptomatic patients without fertility desire. UAE is less effective in adenomyosis than leiomyoma but may provide short-medium term symptom relief. Its relationship with infertility has been proven — reduces IVF success rates (especially JZ >12 mm). Pre-IVF GnRH agonist therapy has improved pregnancy rates in some studies. Endometriosis coexistence is frequent — should be evaluated together in pelvic pain and infertility management. Symptoms generally improve with declining hormone levels at menopause.
Adenomyosis is an important cause of dysmenorrhea, menorrhagia, and infertility. MRI is the gold standard for diagnosis. Medical treatment (hormonal suppression) is first-line. UAE or hysterectomy is considered for refractory cases. Presence of adenomyosis in patients planning IVF may reduce implantation success.