Endometrial osseous metaplasia presented as infertility cases with intra-operative obstacles: Two case reports and literature review

Abstract

Background: Endometrial osseous metaplasia (OM) is a rare condition characterized by the transformation of endometrial tissue into bone cells. Despite its rarity, OM remains a significant contributor to infertility. Although the underlying mechanism remains debatable, an association with previous abortions and curettage has been suggested.

Case presentation: We present two cases of OM presented to the infertility clinic and discuss their similarities and discrepancies in presentation and risk factors. A transvaginal ultrasound raises suspicion about the diagnosis of OM with a hyperechoic mass and post-acoustic shadowing. An office hysteroscopy showed white, mesh-like bony sheets. Both cases underwent operative hysteroscopy to address surgical challenges, and the two cases were followed postoperatively for one year.

Discussion: A comprehensive literature review examined various aspects of OM, including diagnosis, therapeutic options, outcomes, prognosis, and follow-up. Our aim was to raise awareness of this intriguing condition by providing up-to-date knowledge and emphasizing the central role of hysteroscopy in diagnosis and treatment. Here, we present two cases with the same complaint, infertility. Moreover, although the same treatment method was used in both cases, only one achieved pregnancy. This highlights that OM is a possible underlying cause of infertility, in addition to considering other factors that contribute to the overall clinical picture.

Conclusion: OM should be considered in the evaluation of infertility despite its rarity, especially with hyperechoic lesions and acoustic shadowing on ultrasound examination. Hysteroscopy is the gold standard for diagnosis and therapeutic approaches. A complete understanding of the reasons that trigger its growth is crucial. To rule out other differential diagnosis, a holistic evaluation of the patient's history, imaging, and histopathological examination is needed.

Keywords: Endometrial osseous metaplasia; abortion; curettage; diagnostic procedures; hysteroscopy; infertility.

Figure 1.

Transvaginal ultrasound showing an intrauterine hyperechogenicity with post-acoustic shadowing suggestive of calcification associated with chronic endometritis.

Figure 2.

Diagnostic office hysteroscopy showing an adequate endometrial cavity with multiple white, mesh-like boney sheets of varying lengths (5–25 mm) occupying the uterine cavity.

Figure 3.

Endometrial osseous metaplasia lesions completely removed with hysteroscopic forceps.

Figure 4.

Section showing mature lamellar bone trabeculae associated with normal marrow spaces (H&E X200).

Figure 5.

Office hysteroscopy showing a uterine cavity filled with multiple white, mesh-like boney sheets of varying lengths (5–25 mm).

Figure 6.

Multiple endometrial osseous lesions were completely removed using the monopolar cutting loop under hysteroscopic control.

Figure 7.

Section showing mature lamellar bone tissue with normal marrow spaces (H&E X100).

Figure 8.

Section showing non-secretory endometrial glands associated with focal stromal edema (H&E X200).

Figure 9.

Diagnostic scheme for endometrial osseous metaplasia.