Imaging findings in postmenopausal endometriosis

Radiologists play a key role in identifying both recurrent endometriosis and malignant transformations in postmenopausal women.

Key Points

Importance:

•  The importance of this study lies in its recognition that active endometriosis persists in 2-5% of menopausal women, underscoring the critical need to consider malignant transformation during this stage, even when symptoms are absent.

Highlights:

• Imaging findings primarily show adhesion and fibrosis due to low estrogen, with rare cystic and hemorrhagic features in postmenopausal period. 
• MRI can detect malignant transformation of endometriomas, indicated by increased cyst size, solid components, vascularized mural nodules, and loss of T2 shading.

What's done here:

•  Dr. Luciana P. Chamie and colleagues from Brazil provided a comprehensive review of postmenopausal endometriosis, discussing its occurrence theories, typical and atypical radiologic findings, and potential for malignant transformation

Basic outlines:

• The mechanism of postmenopausal endometriosis is unclear, likely due to recurrent, persistent, or de novo disease.
• Postmenopausal hormone replacement therapy increases the risk of symptoms, recurrences, and malignancy, especially with unopposed estrogen.
• MRI is more effective than ultrasonography for diagnosing endometriosis and malignancy in postmenopausal women.
• Postmenopausal endometriosis on MRI shows solid, fibrotic nodules and adhesions, typically without cystic components.
• Endometriosis may have both typical and atypical imaging features based on its phenotype.
• Malignant transformation can occur anywhere, with MRI showing denser, heterogeneous patterns in endometriotic lesions.

Lay Summary

Most women diagnosed with endometriosis during their reproductive years become asymptomatic in postmenopausal period, but lesions remain biologically active despite lower estrogen levels. The pathophysiology of postmenopausal endometriosis remains unclear, though lesions appear less active and extensive.

The risk of malignancy is higher in older women, especially those on estrogen-only therapy. Treatment often involves surgery or estrogen-blocking agents.

MRI is the preferred method for detecting malignancy in postmenopausal endometriosis. Dr. Chamie and colleagues from São Paulo, Brazil, in their Radiographics study, highlighted the fibrotic phenotype of postmenopausal endometriosis, with typical findings such as fibrotic nodules and plaques, showing low signal intensity on T2-weighted MRI. They compared MRI findings between pre and postmenopausal stages for deep endometriosis, endometriomas, and associated lesions, including malignancy.

In conclusion, MRI offers superior resolution over ultrasonography for evaluating adnexal and extrapelvic lesions, making it essential for assessing malign transformation in postmenopausal women with endometriosis. 

Research Source: https://pubmed.ncbi.nlm.nih.gov/39541243/