Postmenopausal endometritis with unusual hysteroscopic findings, Actinomyces-like histopathology, and discordant molecular findings: a case report

Actinomycotic endometritis is rare and is usually associated with prolonged intrauterine device use. Its hysteroscopic morphology remains insufficiently described. As diagnostic approaches now include histopathology, special stains, culture, and molecular microbiologic testing, integrated interpretation is important for recognizing this uncommon infection. A 61-year-old postmenopausal woman presented with two years of foul-smelling purulent vaginal discharge and one year of intermittent vaginal bleeding. She had used an intrauterine device for 13 years, which had been removed 23 years before presentation. No device was retained at admission. Hysteroscopy showed extensive yellow-white and pale-green friable lobulated aggregates within an atrophic uterine cavity. Curettage yielded necrotic tissue. Histopathological examination showed necrotizing suppurative inflammation with Actinomyces -like colonies, and Gram staining demonstrated Gram-positive filamentous organisms. Metagenomic next-generation sequencing of the curettage tissue detected Escherichia coli and Candida parapsilosis , whereas Actinomyces -related reads did not meet the laboratory criteria for positive reporting. The purulent discharge resolved after curettage and empirical antimicrobial treatment. Subsequent hysterectomy showed atrophic endometrium with chronic endometritis and no endometrial malignancy. This case illustrates an unusual postmenopausal intrauterine inflammatory lesion with distinctive hysteroscopic morphology and discordant histopathological and molecular findings. Hysteroscopy is valuable for documenting intracavitary morphology, while histopathology may provide important diagnostic evidence for an Actinomyces -like process when microbiological findings are nonconfirmatory.