Enormous cystic tumor of peritoneal psammocarcinoma exhibiting complete response to Cisplatin and cyclophosphamide after suboptimal cytoreduction: case report and review of the literature

Psammocarcinoma is a serous peritoneal tumor arising from the ovary or the peritoneum and characterized by low-grade nuclear features, extensive psammoma bodies, and invasiveness. Only 62 cases have ever been documented, 30 primary peritoneal and 32 primary ovarian, most of which presented as small tumors. Adjuvant therapies, including chemotherapy and radiation, were performed in 12 of the primary peritoneal cases, without any clear evidence of benefit. We present a case of an unusually large primary peritoneal psammocarcinoma with unexpected outcome. The patient was a 38-year-old woman with a tumor of the peritoneum which adhered densely to the uterus and rectum and developed into the intra-abdominal cavity and retroperitoneal space. After adhesiolysis of the tumor and rectum, suboptimal surgical reduction left a 4 cm × 2 cm tumor segment. Postoperative chemotherapy, consisting of paclitaxel and carboplatin (TC) for 1 course, and cyclophosphamide and cisplatin (CP) for 5 courses, was conducted. The residual tumor responded completely to the chemotherapy and the patient is alive today, with no evidence of disease 15 months after the surgery. Our case implies that CP therapy is a potential regimen of postoperative remission-induction therapy for suboptimally resected primary peritoneal psammocarcinoma.