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Gynecology ICD-10: N80.0

Adenomyosis

A condition where the lining of the uterus grows deep into the muscular wall of the uterus, causing heavy, painful periods and an enlarged uterus.

Source: WHO / CDC / NIH Evidence Guidelines
Updated: Aug 19, 2026
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Red Flag Warning & Emergency Situations

Emergency Management: Symptomatic severe anemia causing syncope or hemodynamic instability, requiring urgent blood transfusion.

Core Definition:

Adenomyosis is a benign uterine condition in which endometrial glands and stroma are ectopically present within the myometrium (the muscular wall of the uterus). This abnormal tissue induces reactive hypertrophy and hyperplasia of the surrounding myometrium, leading to a diffusely enlarged, globular uterus.

Detailed Overview

In adenomyosis, the ectopic endometrial tissue continues to respond to ovarian hormones, resulting in cyclical bleeding deep within the uterine muscle. This entrapped bleeding causes localized inflammation, smooth muscle hypertrophy, and impaired uterine contractility. Clinically, patients present with heavy menstrual bleeding (menorrhagia) and severe cramping (dysmenorrhea). It commonly co-exists with endometriosis and uterine fibroids (leiomyomas), making clinical distinction difficult without imaging.

Epidemiology & Demographics

Most commonly diagnosed in multiparous women between the ages of 35 and 50. Studies suggest an estimated prevalence of 20-30% in the general female population.

Etiological Mechanism

The exact cause is unknown. Leading theories include invagination of the basalis layer of the endometrium into the myometrium due to weakness from uterine trauma (e.g., pregnancy, surgery).

Primary Causes

Downward growth of endometrial tissue into the myometrial layer, stimulated by estrogen.

The boundary between the endometrium and myometrium lacks a submucosa. Disruption of this barrier allows the endometrial basalis to invade the myometrium. The ectopic glands undergo cyclical proliferation, secretion, and sloughing. Because the blood and debris are trapped within the muscle, they incite a chronic inflammatory response. This causes the surrounding myometrium to undergo prominent hypertrophy and hyperplasia, turning the uterus into a bulky, boggy, and globally enlarged organ. The hypertrophic muscle has uncoordinated contractions, leading to severe dysmenorrhea, and the increased uterine surface area contributes to heavy menstrual bleeding.

Diagnostic Criteria & Guidelines

Definitive diagnosis is histological (made after hysterectomy). Clinical diagnosis relies heavily on transvaginal ultrasound or pelvic MRI showing characteristic myometrial changes in a symptomatic patient.

First-Line Treatment:

Medical management for symptoms. Levonorgestrel-releasing intrauterine device (Mirena IUD) is highly effective at reducing bleeding and pain. Alternatively, continuous oral contraceptives (e.g., Ethinyl estradiol/norethindrone) or NSAIDs (Ibuprofen 600 mg PO q6h during menses).

Second-Line & Adjunctive Therapy

GnRH agonists (e.g., Leuprolide acetate 3.75 mg IM monthly) to induce temporary medical menopause and shrink the uterus, usually used short-term or pre-operatively.

Surgical & Procedural Management

Hysterectomy is the only definitive cure, indicated for women who have completed childbearing and failed medical management. Uterine artery embolization (UAE) is an alternative for women wishing to preserve the uterus.

Patient Counseling & Advice

Inform the patient that while medications can control symptoms, adenomyosis will not go away completely until menopause naturally lowers estrogen levels or the uterus is surgically removed.

Follow-Up & Monitoring Schedule

Annual pelvic exams and periodic CBCs to ensure anemia is controlled. Monitor placement of IUD as enlarged uteri may have higher expulsion rates.

Preventive Strategies

No proven primary prevention.

Benign condition, but severely impacts quality of life. Symptoms naturally resolve after menopause. Hysterectomy is 100% curative.

Authoritative Sources & Evidence References
World Health Organization (WHO) & CDC Guidelines: Information compiled from current international clinical practice guidelines.

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