Paratubal Leiomyoma Mimicking Ovarian Malignancy: A Case Report and Literature Review.

Background and Clinical Significance: A paratubal leiomyoma is an exceptionally rare benign smooth muscle tumor arising from paratubal tissue, with only sporadic cases reported in the literature. Case Presentation: We present the case of a 72-year-old postmenopausal woman with intermittent spotting for three months. A pelvic examination revealed a retained intrauterine device, which was removed along with an old sanguineous discharge. A transvaginal ultrasound demonstrated a complex left adnexal mass with calcifications, and computed tomography (CT) confirmed a 7.8 × 5.5 × 4.7 cm lesion suggestive of an ovarian malignancy. Tumor markers showed mildly elevated CA-125 and carcinoembryonic antigen (CEA) levels. Endometrial sampling using a hysteroscopy and curettage revealed hyperplasia without atypia. The patient underwent a total laparoscopic hysterectomy with a bilateral salpingo-oophorectomy. A diagnostic laparoscopy revealed a well-circumscribed solid mass arising from the mesosalpinx, separate from the ovary and fallopian tube and consistent with a paratubal mass, which was successfully excised laparoscopically. Frozen sections suggested a fibroma, and the final pathology confirmed a paratubal leiomyoma with hyalinization, accompanied by adenomyosis and simple endometrial hyperplasia. The patient recovered uneventfully, and the 6-month follow-up showed no recurrence. This case highlights the diagnostic challenge of differentiating paratubal leiomyomas from ovarian tumors based on imaging alone. Histopathological examination is essential for confirmation.

Conclusions

Awareness of paratubal leiomyomas as a differential diagnosis may prevent overtreatment and guide the appropriate surgical management of postmenopausal women presenting with adnexal masses.