Infiltrative mesenteric desmoid tumor, main duct mucinous neoplasm of the pancreas

Case contributed by Dr Michael P Hartung


Abdominal discomfort.

Patient Data

Age: 65 years
Gender: Male

Moderate intrahepatic and common bile duct dilation to the ampulla. 

Massive cystic dilation of the main pancreatic duct and sidebranches. No solid enhancing nodules. Stranding about uncinate process indicating component of pancreatitis. Small calcifications in the pancreatic tail. 

Non-obstructive left renal stones. 

Total colectomy with right upper quadrant ileostomy. 

Extensively infiltrative mesenteric mass which extends into the right paracolic gutter. 



  1. Acute recurrent pancreatitis.

  2. Abdominal CT, post cholecystectomy, pancreatic duct 1.3 cm with a 7 x 2.4 cm cystic lesion in the tail of the pancreas with multiple pancreatic calcification. A 3.4 cm head of the pancreas cystic lesion, soft tissue in the small bowel.

  3. History of colectomy for multiple colon polyps in 1976 and desmoid tumor resection in 1977.


  1. EGD revealed a normal GE junction at 45 cm, innumerable gastric polyps measuring 3-4 mm, excisional biopsy performed x3. The second and third part of the duodenum revealed 8 flat duodenal polyps measuring between 8 mm to 60 mm. The largest polyp was seen distal to the ampulla on the lateral duodenal wall encompassing the hemicircumference. Multiple biopsies were obtained. The ampulla had the classical fish-mouth appearance.

  2. EUS revealed a 6.1 x 4.9 cm dilated heterogeneous cystic structure in the body of the pancreas. FNA with a 19-gauge needle was performed x1 with aspiration of 3 cc of thick mucoid aspirate. The aspirate was sent for CEA, amylase CA 19-9 and the cyst wall for cytology. The patient received 500 mg of Levofloxacin.

  3. The rest of the pancreatic duct appeared markedly dilated to 1.5 cm with minimal diminution to the tail of the pancreas. The head of the pancreas is also replaced by a 2.8 x 2.8 cm heterogeneous multi-cystic lesion. No distinct mural nodules. There were multiple parenchymal calcifications within the cystic collection in the region of the tail of the pancreas. The common bile duct measured 12 mm with no filling defect. The gallbladder is surgical absent. No peripancreatic adenopathy.


  1. EGD with biopsy.

  2. Linear endoscopic ultrasound with fine-needle aspiration.



SLIDE(S): 2 CB Slide(s) 2 Thin Prep(s)

GROSS DESCRIPTION: 20 mL, Fresh, Cloudy. Needlewash Received.

RESULTS: Neoplastic Mucinous Cyst.

Concurrent Cyst Fluid Analysis Yields:

CEA = 2705.9 ng/mL

CA 19-9 = 6194 U/mL

Amylase = 18 U/L

REMARKS: In The Context Of An Elevated CEA Level, Thick Mucoid Appearance Of

The Fluid And The Fish Mouth Appearance Of The Ampulla, These Findings Are

Compatible With An Intraductal Papillary Mucinous Neoplasm.

Case Discussion

Very complex case. Classical finding of main duct mucinous neoplasm of the pancreas, which carries around a 65% risk of harboring carcinoma.

The key to understanding the mesenteric findings is noticing that this patient had a total colectomy, and then asking "why?". 

At the time of this dictation, no additional history was given, therefore, this fact was (cruelly) withheld from the presentation. This patient underwent total colectomy many years prior for familial polyposis and resection of desmoid tumor in the 70's. 

This is a great example of a more insidious appearance of intra-abdominal desmoid, which can have a mass-like, infiltrative, or combined appearance. FAP patients are at particularly notable risk after colectomy. 

Companion solid mesenteric desmoid.

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Case information

rID: 63857
Published: 23rd Oct 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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