Solid pseudopapillary neoplasm-diagnostic approach and post-surgical follow up: Three case reports and review of literature

BACKGROUND: Solid pseudopapillary neoplasm (SPN) is a rare tumor that was first described by Frantz in 1959. Although this tumor is benign, some may have malignant potential that can be predicted based on demographics, imaging characteristics, and pathologic evaluation. This case series presents 3 SPN cases with discussion on gender differences, preoperative predictors of malignancy, and a suggested algorithm for diagnostic approach as well as post-surgical follow up. CASE SUMMARY: Three adult patients in a tertiary hospital found to have SPN, one elderly male and two young females. Each of the cases presented with abdominal pain and were discovered incidentally. Two cases underwent endoscopic ultrasound with fine needle aspiration and biopsy to assess tumor markers and immuno-histochemical staining (which were consistent with SPN before undergoing surgery), and one case underwent surgery directly after imaging. The average tumor size was 5 cm. Diagnosis was confirmed by histology. Two patients had post-surgical complications requiring intervention. CONCLUSION: Demographic and imaging characteristics can be sufficient to establish diagnosis for SPN, while malignant cases require pre-operative evaluation with endoscopic ultrasound fine needle aspiration/fine needle biopsy.