Pancreatic solid pseudopapillary neoplasm: a single-institution study

Solid pseudopapillary neoplasms (SPNs) are a distinct but rare form of low-grade pancreatic neoplasia, accounting for 0.3%-2.7% of all pancreatic tumours. They are most common in young females. Local recurrence and distant metastasis are reported but extremely rare, and are usually resectable with curative intent. We report the clinicopathological features and long-term outcomes of SPNs following surgical resection from a single institution.

A total of 1296 patients undergoing pancreatic resection during the 30 years period from 1991 to 2020 were retrospectively reviewed, and those with a confirmed pathological diagnosis of pancreatic SPN on review were included.

Twenty-two patients (1.7% of all patients undergoing resection), were identified. Twenty patients (91%) were female. Unlike previous studies, most patients (91%) were symptomatic at diagnosis. On diagnostic CT, cystic components were visible in 16 patients (73%), calcifications were found in two patients (9%), haemorrhage in one patient (5%) and a defined capsule was seen in four patients (18%). Surgical resection was undertaken on all cases, with distal pancreatectomy the most commonly performed (n = 11, 50%). One patient (4.7%) had nodal involvement, nine patients had an incomplete tumour capsule (41%) and seven patients (32%) had tumour extension into the pancreatic parenchyma. Despite this, no patients had disease recurrence at 10 years. One patient died within 5 years of heart failure unrelated to the SPN process; no patients died within 10 years of the disease.

We confirm a high proportion of female patients. Interestingly, a high proportion of our cohort was investigated for symptomatic disease. Despite a high proportion of tumours with an incomplete capsule, and extension into the pancreatic parenchyma, our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.