An Adult Massive Retroperitoneal Mature Teratoma: A Case Report and Literature Review

Teratomas usually occur in the gonads. The retroperitoneum is the least common location, which accounts for approximately 4% of primary retroperitoneal tumors and 26% of retroperitoneal teratomas are malignant. Retroperitoneal teratomas occur mainly in childhood, and with a low incidence in adults. Due to its nonspecific clinical and imaging features, the disease is difficult to distinguish from cystadenoma and other diseases, making accurate diagnosis a persistent clinical challenge.

Here, we present a 65-year-old female patient who was admitted to the hospital due to intermittent right upper abdominal pain for half a month. Preoperative abdominal computed tomography imaging revealed a large mass in the left abdominal cavity, which showed mild enhancement. However, the imaging findings were non-diagnostic, and the nature of the mass could not be determined. Postoperative pathological examination revealed a retroperitoneal mature cystic teratoma. Through close follow-up, the patient achieved a favorable prognosis, and had no local recurrence or distant metastasis 6 years after surgery.

This case highlights the importance of considering teratoma in the differential diagnosis of retroperitoneal tumor and emphasizes the importance of complete surgical resection for the patient's prognosis, which are critical to preventing misdiagnosis as malignancy and optimizing patient outcomes.