Cystic Neoplasm of the Pancreas Clinical Review of 60 Cases and Treatment Strategy D.K.Kim, S.I.Noh, J.S.Heo, J.H.Noh, T.S.Sohn, S.J.Kim, S.H.Choi, J.W.Joh, Y.I.Kim   Department of Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea Ladies and gentle men. I’ll talk about cystic neoplasm of the pancreas, Clinical Review of 60 Cases and Treatment Strategy .

Introduction

Pancreatic cystic neoplasms are rare. There are still many unclear points. It is difficult to differentiate benign from malignant neoplasm. Surgery or observation? when benign cystic neoplasm is presumed. pancreatic cystic neoplasms are rare but interesting tumors because of their high cure rate after surgery. With the exception of serous cystadenomas, which are always benign , these cystic neoplasms are either premalignant or malignant. Although there are trials to differentiate these neoplasm, It is still unclear and treatment plan may be confusing. We reviewed our experience to suggest malignant risk factor and treatment plan.

Methods

From Oct.1994 to Nov. 1999 at Samsung Medical Center 60 patients, diagnosed as a cystic neoplasm of the pancreas preoperatively Depending on pathology, they were divided into benign group and malignant group (premalignant or malignant) and clinical findings were analyzed. Radiological diagnostic value was also reviewed. Statistics -t test, Chi-square test, Fisher’s exact test From Oct.1994 to Nov.1999, 203 patients had undergone surgery for pancreatic tumors at SMC. 60 patients, diagnosed as a cystic neoplasm preoperatively were reviewed retrospectively. Clinically clarified pseudocysts were excluded. In order to suggest malignant risk factors, they were divided into benign group and malignant group and compared using T test, chi square test, and fisher’s test. Radiological diagnostic value was also reviewed.

Results

1. Pathology of Cystic Neoplasm Pathologic type No. of patients (Malignant) Malignant group* 37 (10) Mucinous cystic neoplasm 13 ( 2) Solid-pseudopapillary tumor 11 Intraductal papillary mucinous neoplasm 10 ( 5) Cystic islet cell tumor 2 ( 2) Metastatic papillary carcinoma** 1 ( 1) Benign group 23 Serous cystadenoma 10 Pseudocyst 6 Benign retension cyst 4 Simple cyst 2 Lymphoepithelial cyst 1 Total 60 (10) *It include malignant and premalignant neoplasm. ** From intrahepatic carcinoma. In malignant group, MCN was most common and SPN, pancreatic duct ectasia, cystic islet cell tumor and metastatic papillary carcinoma were included. In benign group, serous cystadenoma was most common and pseudocyst, retension cyst, simple cyst, and lymphoepithelial cyst were included.

2. Age and Sex Benign group Malignant group p-value Age 20~70 years 16~76 years NS* (Mean age) (48.9 years) (48.5 years) Sex Male:Female 7:16 27:10 0.001 *NS; Non-Significant (p>0.05) There was no difference in age between the groups, but malignant group occurred more commonly in female.

3. Clinical Findings Benign group Malignant group p-value (n=23) (n=37) Abdominal pain 12 21 NS No symptom 11 12 NS DM 3 7 NS Weight loss 2 3 NS Anorexia 0 5 NS Abdominal mass 0 4 NS Jaundice 0 2 NS In both group, abdominal pain was most common symptom

4. Past and Social History Benign group (%) Malignant group (%) p-value (n=23) (n=37) Pancreatitis 4 (17.4) 8 (21.6) NS Biliary stone 1 ( 4.3) 2 ( 5.4) NS Alcoholic abuse 7 (30.4) 2 ( 5.4) 0.021 The history of pancreatitis or biliary stone was not different between the groups but there were more alcoholic abuse in benign group.

5. Laboratory Findings Benign group Malignant group p-value (n=23) (n=37) Serum amylase High:Normal 3:20 4:33 NS Serum lipase Serum CA 19-9 High:Normal 1:22 8:29 NS Serum CEA High:Normal 0:23 2:35 NS There was no difference in the level of pancreatic enzyme and tumor markers.

6. Locations Tail Body Head Benign group Malignant group there was no difference in the distribution of tumor locations. Malignant group

7. The Size of Tumors Malignant group benign group Cumulative count 40 Mean: 5.6 cm 30 20 benign group Mean: 3.8 cm 10 Cumulative count This graph shows the cumulative counts according to tumor size. The tumors in malignant group were significantly larger than tumors in benign group. Especially, the difference was more significant in more than 6cm.   0 1 2 3 4 5 6 7 8 9 >10 Size (cm) p=0.014

8. Diagnostic Value of CT Preoperative Benign group (%) Malignant group (%) diagnosis (n=23) (n=37) Malignant 4 (17.4) 14 (37.8) or premalignant Benign 3 (13.0) 2 ( 5.4) Undetermined 16 (69.6) 21 (56.8) On CT scan, malignancy was undetermined in majority. 2 cases out of 5 cases , diagnosed as benign lesion preoperatively were diagnosed as premalignant tumor postoperatively

9. Diagnostic Value of US Preoperative Benign group (%) Malignant group (%) diagnosis (n=13) (n=18) Malignant 1 ( 7.7) 4 (22.2) or premalignant Benign 2 (15.4) 3 (16.7) Undetermined 8 (61.5) 11 (61.1) Non-specific 2 (15.4) 0 ( 0.0) US had similar results to CT scan, but it was more non-specific.  

10. Diagnostic Value of ERCP Preoperative Benign group (%) Malignant group (%) diagnosis (n=21) (n=18) IPMN 2 ( 9.5) 8 (44.4) Ductal carcinoma 1 ( 4.8) 0 ( 0.0) Ductal compression 5 (23.8) 3 (16.7) by mass Pancreatitis 3 (14.3) 2 (11.1) or pseudocyst Non-specific 10 (47.6) 5 (27.8) ERCP was useful in the diagnosis of some cases of duct ectasia and pseudocyst. But it was also non-specific to differentiate the groups

Left case was diagnosed as serous cystadenoma after surgery and right case was mucinous cystadenoma. It was difficult to differentiate the precise types of tumors on CT. CT of a serous cystadenoma (Left) and a mucinous cystadenoma (Right). It was difficult to differentiate the precise types of tumors on CT.

11. Operations Pancreaticoduodenectomy 14 Distal pancreatectomy 41 Total pancreatectomy 3 Distal pancreatectomy and pancreaticoduodenectomy were performed in majority. A case of simple cyst superficially located in pancreatic tail underwent enucleation and median segmental pancreatectomy was performed in a case of small sized mucinous cystadenoma located in pancreatic body. 1 Median segmental pancreatectomy 1 Enucleation

12. Postoperative Course No. of patients Total (%) Operative mortality 0 0 ( 0.0) Postoperative complications 11 (18.3) Pancreatic leakage 5 Infection* 2 Bile leakage 1 Bleeding 1 Miscellaneous ** 2 Recurrence*** 3 3 ( 5.0) * Pneumonia and wound infection **Intestinal obstruction and brain infarction ***Two malignant IPMNs and one malignant islet cell tumor. . Operative complications occurred in 11 cases, but there was no mortality. In 2 cases of malignant duct ectasia and a case of malignant islet cell tumor, there were recurrences  

13. Review of Malignant Risk Factors* No. of included Benign group (%) Malignant group (%) factors (n=23) (n=37) 0 8 (34.8) 2 ( 5.4) 1 8 (34.8) 5 (13.5) 2 7 (30.4) 18 (48.6) 3 0 ( 0.0) 12 (32.5) * Malignant risk factors -Large sized tumor (more than 6 cm) -Female -No alcoholic abuse Malignant risk factors which had significant difference in these results, size, sex, and alcoholic history, were reviewed again. The cases including all risk factors were 12 cases and all was malignant group.  

Conclusions

Because it is difficult to determine the malignancy of pancreatic cystic neoplasms preoperatively, all these lesions should be treated with surgical resection. If operation risk is high, malignant risk factors may be useful in deciding treatment plan. Because it is difficult to determine the malignancy of cystic pancreatic neoplasms preoperatively, all these lesions should be treated with surgical resection. However, if operative risk is high, malignant risk factors may be useful in deciding treatment plan.   Thank you.