Synchronous presentation of endometrial adenocarcinoma and incidental paratubal borderline serous tumor: A rare case report

Introduction

Paratubal cysts, commonly benign and incidentally found during hysterectomy or salpingectomy, are often termed “hydatid cysts of Morgagni.” While most are benign, borderline and malignant subtypes are rare. This report presents an unusual case of synchronous malignancies involving an endometrioid adenocarcinoma and a paratubal borderline serous tumor, emphasizing the need for careful examination of paratubal cysts.

Main symptoms and/or clinical findings

A 61-year-old postmenopausal woman presented with two months of vaginal bleeding and lower abdominal pain. Elevated CEA and CA 19-9 levels were noted. Ultrasonography showed thickened endometrium and moderate pyometra, and MRI revealed a lesion in the upper endometrium involving the myometrium without extrauterine extension. An endometrial biopsy indicated endometrial intraepithelial neoplasia.

Main diagnoses, therapeutic interventions, and outcomes

The patient underwent a staging laparotomy, bilateral salpingo-oophorectomy, hysterectomy, and pelvic lymphadenectomy. Histopathology confirmed endometrioid adenocarcinoma (FIGO grade II, stage IB) and identified a left paratubal cyst with borderline serous tumor features. Immunohistochemical analysis supported these findings. The post-operative period was uneventful, and the patient remains under follow-up with no signs of recurrence or metastasis.

Conclusion

This case underscores the importance of thorough examination of paratubal cysts. The rare coexistence of endometrioid adenocarcinoma with a borderline serous paratubal tumor highlights the necessity for detailed histopathological and immunohistochemical evaluation in synchronous malignancies. Such meticulous examination ensures accurate diagnosis and appropriate management, potentially enhancing patient outcomes.