What is adenomyosis in women of reproductive age, particularly those between 40 and 50 years old?

What is Adenomyosis?

Adenomyosis is a benign uterine disease where endometrial glands and stroma are abnormally located within the myometrium (uterine muscle), causing inflammation, fibrosis, and hypertrophy of surrounding smooth muscle cells. 1

Pathophysiology

Adenomyosis represents a condition where tissue that normally lines the inside of the uterus grows into the muscular wall of the uterus. 2 The disease involves:

• Endometrial tissue invasion into the myometrium, where it elicits hyperplasia and hypertrophy of surrounding smooth muscle cells 2
• Chronic inflammation and fibrosis as the disease progresses, essentially representing wounds undergoing repeated tissue injury and repair 3
• Hormonal abnormalities, neuroangiogenesis, and smooth muscle metaplasia contributing to disease progression 1

Clinical Presentation in Reproductive-Age Women

Women with adenomyosis, particularly those aged 40-50 years, commonly present with:

• Heavy or prolonged menstrual bleeding (abnormal uterine bleeding) that may disrupt daily activities 4
• Pelvic pain and dysmenorrhea resulting from increased uterine contractility, hyperinnervation, and production of pain mediators 3
• Infertility or subfertility in some cases 1, 5
• Asymptomatic presentation in a subset of women despite imaging findings 1

Diagnostic Approach

Imaging Modalities

Transvaginal ultrasound (TVUS) serves as the first-line diagnostic tool:

• Demonstrates 82.5% sensitivity and 84.6% specificity for adenomyosis 6, 7
• May have reduced sensitivity (33.3%) when coexisting leiomyomas are present 6

MRI pelvis provides superior characterization when ultrasound is inconclusive:

• Offers multiplanar capabilities and excellent tissue contrast 6
• Can identify adenomyosis even when obscured by leiomyomas or other pathology 6
• Demonstrates 82-90% sensitivity and 91-98% specificity 7

Disease Phenotypes

Adenomyosis presents in different anatomical forms:

• Diffuse adenomyosis: widespread involvement of the myometrium 5
• Focal adenomyosis: localized lesions (adenomyomas) 5
• Distinction between external and internal myometrial involvement affects clinical characteristics 5

Common Pitfalls

Coexisting pathology frequently complicates diagnosis, as adenomyosis often occurs alongside:

• Endometriosis 1
• Uterine fibroids (leiomyomas), which can obscure imaging findings 6, 1

Historical underdiagnosis occurred because adenomyosis was traditionally considered only a histopathological diagnosis after hysterectomy in perimenopausal women. 1 Modern imaging now allows non-invasive diagnosis in younger reproductive-age women. 1