Endometrial and cervical osseous metaplasia with extramedullary haematopoiesis presenting as amenorrhea: Report of three cases

Endometrial Osseous Metaplasia-A Rare Cause of Infertility with Unknown Etiology

Background: Osseous tissue in the endometrium is a rare find, and it is most often discovered when the patient presents with infertility. It is frequently associated with dysmenorrhea and abnormal menstrual bleedings. Although its etiology remains unclear, in almost all described cases until now, the patient has an obstetrical history. Case report: In this report, we present a unique case of endometrial osseous metaplasia in a 27-year-old primary infertile patient. The transvaginal ultrasound revealed a 18/13/7 mm hyperechoic endometrial mass with posterior acoustic shadowing and no flow on color Doppler. A hysteroscopic examination found a polygonal calcification on the endometrial posterior face of the uterine cavity, in the corporeal isthmic region, which was extracted. The histopathological evaluation revealed microscopic elements compatible with endometrial calcification. The patient had a good postoperative course and the complex endocrinologic, immunologic and electrolytical investigation failed to prove any abnormality. Follow-up transvaginal ultrasound examinations revealed no modifications. Three years later, the patient conceived spontaneously, had an uneventful pregnancy and delivered a full-term fetus. Conclusion: We assumed that this entity can be a serious cause of infertility since the patient had a long history of (primary) infertility and its resection made the pregnancy's occurrence possible. Finally, since neither history of abortion or chronic inflammation nor any abnormal laboratory test were noticed, we concluded that the etiology of this entity remained unclear.

Imaging of endometrial osseous metaplasia—an uncommon but treatable cause of infertility

Background

Endometrial osseous metaplasia (EOM) is an uncommon condition characterised by metaplastic transformation of endometrial tissue into osteoblasts (mature or immature bone in the endometrium). Etiopathogenesis of EOM is explained by multiple putative mechanisms like dystrophic calcification, metaplastic ossification, retained foetal bones after abortions and genito-urinary tuberculosis. EOM has varied clinical presentation ranging from patient being asymptomatic to secondary infertility. Although hysteroscopy is the gold standard for its diagnosis and treatment, non-invasive imaging comprising chiefly of ultrasonography (USG) is increasingly becoming the mainstay of diagnosis. We aim to present the imaging findings in EOM to acquaint radiologists and gynaecologists with this condition to avert misdiagnosis of this uncommon yet treatable cause of infertility.

Results

Mean age of patients was 31.4 ± 5.4 (S.D) years. USG revealed linear or tubular densely echogenic endometrium with posterior acoustic shadowing in all the 14 patients. MRI in 3 patients revealed diffuse or patchy areas of T1W and T2W hypointense signal intensity with unilateral (n = 2) and bilateral (n = 1) ovarian cysts. One patient who underwent CT scan revealed dense endometrial calcification. Histopathologic examination (HPE) revealed lamellar (n = 6) or trabecular (n = 4) bone within endometrium (EOM) and inflammatory cells with calcification in four patients (calcific endometritis). Twelve patients conceived after dilatation and curettage within 15 months.

Conclusion

Familiarity with the imaging appearances of EOM is indispensable to clinch this diagnosis and avert misdiagnosis of this rare but potentially treatable cause of infertility. USG is usually sufficient for diagnosis. MRI and CT are only supplementary tools in difficult clinical scenarios.