Clinical management of a unique case of PNET of the uterus during pregnancy, and review of the literature.

Rationale: PNETs (primitive neuroectodermal tumors) are a family of highly malignant neoplasms characterized by small round cells of neuroepithelial origin. They usually involve bone and soft tissues, and have a higher incidence in childhood.

Patient Concerns: In this case report, we describe the obstetric and oncological outcome of a huge mass diagnosed as a leiomyoma in a 39-year-old pregnant woman who complained of low back pain, dysuria, and urinary frequency at 22 weeks of gestation.

Diagnoses: During the 25th week of pregnancy, the patient was referred to our hospital at night with severe anemia and suspected hemoperitoneum. She underwent an emergency caesarean section, delivering a female fetus weighing 400 g, with an Apgar score of 7 at 1 minute and 9 at 5 minutes.

Intervention: During surgery, we found a huge uterine sarcoma-like metastatic tumor, invading the pelvic peritoneum and parametria bilaterally; the adnexae seemed disease-free. We performed a type B radical hysterectomy, bilateral salpingo-oophorectomy, pelvic peritonectomy, omentectomy, appendectomy, and excision of a bulky lymph node. Seven days after delivery, staging computed tomography (CT) scan demonstrated a large lombo-aortic lymph node compressing the left renal vein and we completed debulking with a second surgery, including diaphragmatic peritonectomy and excision of a huge lymph node by lombo-aortic lymphadenectomy, requiring partial reconstruction of an infiltrated renal vein.

Outcome: Ten days after the second surgery, echo-color Doppler showed a regular microcirculation in the left kidney. The patient was discharged after 10 days, and the baby after 1 month, both in good health.Histological examination revealed a uterine body cPNET (central primitive neuroectodermal tumor) orienting the clinical management toward chemotherapy with cisplatin and etoposide.

Lessons: PNETs are aggressive neoplasms, usually diagnosed at an advanced stage. Due to their low incidence, universally accepted guidelines are still unavailable. Radical surgery leaving no macroscopic residual disease is mandatory in advanced stages. A good fertility-sparing procedure can be performed only in young women at early stages of disease, when the wish for childbearing is not yet fulfilled.