A Rare Case of Recurrent Metastatic Solid Pseudopapillary Neoplasm of the Pancreas

A 61-year-old woman visited our hospital for bilateral multiple lung nodules and a mass in her thorax. She had a long history of multiple metastatic recurrences of solid pseudopapillary neoplasm (SPN); 24 years previously, the patient had undergone pylorus-preserving pancreaticoduodenectomy for a 9.9 × 8.6 cm mass in the pancreatic head. The tumor was diagnosed as an SPN. Nine years later, metastatic nodules were found on computed tomography in the patient’s liver and peritoneum and were excised. She subsequently underwent an additional eight metastatectomy procedures in diverse organs. For the presented event, the lung nodules were removed. The prevalence of malignant SPN in the general population is 5%–15%. However, multiple metastatic recurrence of malignant SPN is rare; the lung is a particularly rare site of metastasis, found in only three cases in the literature. Here, we describe this exceptional case and provide a literature review.