OBJECTIVETo study the clinicopathologic and immunohistochemical features, biological behavior, diagnosis and treatment of solid pseudopapillary tumor of the pancreas (SPTP).

METHODSA retrospective clinical and clinicopathologic analysis was made on 33 cases of SPTP admitted from May 2001 to 2010 July. There were 7 male and 26 female patients, aging from 13 to 66 years with a mean of 34.3 years.

RESULTSThe tumor was located in pancreatic head of 10 patients, in pancreatic neck of 5 patients, in pancreatic body and tail of 18 patients. Of the 33 patients treated with surgery, 8 underwent simple resection of pancreatic tumor, 6 underwent pancreaticoduodenectomy, 3 underwent tumor resection plus pancreaticojejunostomy, 1 underwent tumor resection plus pancreaticogastrostomy, 11 underwent distal pancreatectomy, 4 underwent distal pancreatectomy plus spleen resection (1 underwent mesohepatectomy for hepatic metastasis). Sixteen of the 33 operations were completed by laparoscopy. Histologically, tumors were composed of papillary and microcystic solid structures, with uniformed population of cells. The pancreas and blood vessels invasion were identified in 3 cases, one of them was combined with liver metastasis, and they are male. Immunohistologically, the tumors were positive for α1-antitrypsin, α1-antichymotrypsin, β-catenin, CD10, CD56 and vimentin (all cases), neuron-specific enolase (3 cases), synaptophysin (6 cases), chromogranin A (4 cases), progesterone receptor (28 cases), estrogen receptor (3 cases), S-100 (6 cases). Totally 33 cases were followed up with a median period of 49 months without tumor recurrence.

CONCLUSIONSSPTP is of low graded malignancy. It primarily affects young women. It may be located in any part of pancreas. Immunohistochemistry is very important for the diagnosis and differential diagnosis of SPTP. Surgical resection is recommended as the treatment of choice. Laparoscopic distal pancreatectomy or tumor resection is feasible and safe for some selected patients, and the prognosis is good.