Endometrioma: A Comprehensive Review of Its Varied Presentations, Complications, and Impact on Patient Management

Abstract

Endometriosis is a disease characterized by the presence of endometrium-like glands and/or stroma outside the uterus, usually with an associated inflammatory process. Endometrioma, a common manifestation of endometriosis, typically presents as an ovarian or adnexal cyst containing blood products at varying stages of degradation. While the typical ovarian/adnexal endometrioma is well recognized on imaging, atypical presentations and mimics can pose a diagnostic challenge. Endometriotic cysts can occur in unexpected locations, including within or on the surface of the liver, pancreas, peritoneum, and along the nerves, to name a few locations. Endometriomas can be associated with complications such as infection, rupture, and malignant transformation. An endometrioma is a marker of deep endometriosis, necessitating evaluation for the same. Endometriosis is seen in ∼50% of patients with infertility. Surgical management to improve fertility may include the excision of ovarian endometriomas with an impact on ovarian functional reserve. Finally, in pregnant patients, preexisting endometriomas may undergo decidualization and resemble ovarian malignancy, further adding to the diagnostic conundrum. This review article will describe the typical and atypical imaging features of an endometrioma, its associations, and complications, as well as its implications on patient management. Throughout this article, the term “endometriotic cyst” will be used for lesions located outside the ovary/adnexa.

Key Points

1. Endometriomas are the most commonly recognized form of endometriosis, both on ultrasound and MRI. They are cystic structures containing blood products at varying stages of degradation, lined by a thick wall containing inflammatory tissue as well as endometrium-like glands and stroma.

2. An ovarian endometrioma is a marker of the presence of deep endometriosis, a more severe form of the disease—which should be actively sought for—whenever an endometrioma is seen on imaging.

3. Any enhancing mural nodule within an endometrioma warrants further evaluation regardless of its size. Although some enhancing mural nodules can be benign, more commonly, they represent malignant degeneration and should therefore be considered for surgical management.

4. Ectopic endometrial glands/stroma within endometriomas in pregnant women respond to hormonal changes in pregnancy, similar to eutopic endometrium and undergo an increase in size and vascularity (decidualization). Decidualized endometriomas seen in pregnancy contain papillary projections that are benign; however, they can resemble and are often mistaken for malignancy.

5. Complications such as infection, rupture, torsion, and malignant transformation have been reported with endometriomas.

Keywords

ovarian endometrioma - endometriosis - transvaginal ultrasound - magnetic resonance imaging - infertility - malignant degeneration

Publikationsverlauf

Artikel online veröffentlicht:
22. Mai 2025

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