Clinical features and treatment of solid pseudopapillary neoplasm of the pancreas / 中华消化外科杂志

ABSTRACT

Objective To investigate the clinical features and treatment of solid pseudopapillary neoplasm (SPN) of the pancreas.Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 69 patients with SPN of the pancreas who were admitted to the Qilu Hospital of Shandong University from January 2012 to July 2017 were collected.Serum tumor markers detection,enhanced computed tomography (CT) and magnetic resonance imaging (MRI) of abdomen were carried out preoperatively for all the patients,and a part of the patients received endoscopic ultrasonography (EUS).Surgery plans were formulated after completion of examinations.Observation indicators(1) clinical features;(2) treatment situation;(3) results of pathological examination;(4)follow-up.All the patients were followed up via outpatient examination and telephone interview to detect the survival and tumor recurrence and metastasis till July 2017.Measurement data with normal distribution were presented by (x)±s and were compared by Student's t test.Count data were compared by chi-square test.Results (1) Clinical features① epidemiologic featuresthe ratio of male to female was 1∶5.9;patients were aged between 9 and 65 years,including 40 under 30 years and 29 above or equal to 30 years.The onset age was (34± 15)years for male patients and (28 ± 11)years for female patients,respectively,with no statistically significant difference (t=1.364,P＞0.05).Of 69 patients,SPN was located at pancreatic uncinate process in 25 patients,at neck of pancreas in 12 patients,body and tail of pancreas in 32 patients.② Medical historyhistory of acute or chronic pancreatitis and abdominal trauma were denied by all the 69 patients.③ Clinical manifestation26 patients had no obvious symptoms and were detected by physical examination;31 patients had discomfort in upper abdomen,nausea and vomiting;other patients were admitted to the hospital because of upper abdominal mass (10 patients),jaundice (1 patient) or nausea,constipation (1 patient).④ Laboratory examinationthe levels of preoperative carcinoembryonic antigen (CEA) and CA19-9 were normal.⑤ Imaging examinationplane scan of the CT examination showed round or round-like low-density shadows in the 69 patients,including 51 of cystic solid lesion,13 of solid lesion and 5 of cystic lesion.Complete capsules were observed in 64 patients,blurred boundary between pancreas and adjacent viscera in 5 patients,calcified foci in the pancreatic parenchyma and capsules in 14 patients.Ten patients received MRI examination,and the T1-weighted images showed equal or slightly lower signal,T2-weighted images showed slightly higher signal in the plane scan,and T1-weighted and T2-weighted images of the tumor capsule showed continuous or non-continuous ring-like signal.The results of enhanced scan showed slightly heterogeneous enhancement of the capsule and the parenchyma of the pancreas in the arterial phase,and progressive enhancement in the venous and delayed phase,while the enhancement degree was lower than that of the normal pancreas parenchyma.The parenchyma was cloud-,papillaor mural nodule-like enhanced.Obvious enhancement was observed in capsule while not in the cystic components.The boundaries of the tumors in 5 patients were clear under EUS.Hypo-,iso-and hyperechoic regions were found in the masses,and the masses were confirmed as cyst-solidary type.Obvious calcified foci were found in 1 patient.(2) Treatment outcome:twenty-seven patients received laparoscopic surgery,including tumor expiration in 13 patients,distal pancreatectomy with preservation of spleen in 8 patients,distal pancreatectomy combined with splenectomy in 2 patients,middle pancreatectomy in 2 patients,pancreaticoduodenectomy with preservation of pylorus in 1 patient,pancreatic head resection with preservation of duodenum under the assistance of laparoscopy in 1 patient.Forty-two patients received open surgery,including tumor expiration in 12 patients,distal pancreateetomy with preservation of spleen in 10 patients,distal pancreatectomy combined with spleneetomy in 6 patients,middle pancreatectomy in 5 patients,pancreaticoduodenectomy in 7 patients (with preservation of pylorus in 2 patients) and pancreatic head resection combined with preservation of duodenum in 1 patient.One patient with SPN + hepatic metastasis received distal pancreatectomy+ metastatic foci resection in the lesser omental bursa,and then followed by radiofrequency ablation in the hepatic metastatic foci.Postoperative complications21 of 69patients had postoperative complications,including 17 intestinal fistulas,2 abdominal bleedings,1 incomplete obstruction,1 pleural effusion + atelectasis,and all of them were cured by symptomatic treatment.(3)Pathological examinationthe resection margins of 69 patients were negative.The mean diameter of the tumor was (7±4) cm (21 patients with tumor diameter ＜ 5 cm,and 48 with tumor diameter ≥5 cm).The tumor diameters of 4 in 10 male patients were above or equal to 5 cm,and the number was 44 in 59 female patients,with statistically significant difference (x2 =4.828,P＜0.05).The tumor diameters of 32 in 40 patients who aged under 30 years were above or equal to 5 cm,and the number was 16 in 29 patients who were aged above or equal to 30 years,with statistically significant difference (x2=4.895,P＜0.05).Solid,pseudo-papillary and cystic regions in the SPN tissues were seen under the light microscope.Tumor cells were surrounded the blood vessels and were arranged in the nest or sheet shape in the solid region;blood vessels were surrounded by one or multiple layers of tumor cells in the axis or pseudopapillary shape in the pseudopapillary region;large amount of mucus and clusters of blood cells were seen in the cystic regions.The result of immunohistochemistry showed that the positive rates of α1-antitrypsin,vimentin,β-catenin,progesterone receptor,CD10,synaptophysin and chromogranin A were 100.0％ (39/39),96.6％ (28/29),95.7％ (45/47),94.4％ (51/54),92.5％ (49/53),72.9％ (35/48) and 5.6％ (3/54),respectively.(4) Follow-up63 of 69 patients were followed up for 1-68 months,with median time of 29 months.No SPN recurrence or metastasis was detected.One patient died of lung cancer at postoperative month 35 and other patients survived well.Conclusions SPN of pancreas is mostly detected in young female patients,and it could be solid or cystic.Abdominal enhanced CT or MRI examination could clarify the diagnosis.EUS-fine needle aspiration examination could provide pathological evidence for definitive diagnosis.Typical cellular morphology and pseudopapillary regions may provide hints for the diagnosis of SPN,and the diagnosis could be clarified when combined with the detection of vimentin,α 1-antitrypsin or other indexes.Complete resection of SPN and ensure negative resection margin are fundamental principles of treatment.