IPMNs can come to clinical attention in a variety of different ways. They can be asymptomatic and detected incidently on imaing. Howver; when symptoms are present, they are usually nonspecific including abdominal pain, back pain, nausea, vomiting, anorexia and weight loss. They can also present with jaundice caused by obstruction of the bile ducts due to external compression or invasion or pancreatitis-like symptoms due to obstruction of the main pancreatic duct by mucin.[12]

The evaluation of IPMNs usually starts with imaging to evaluate the characteristics of the cyst, involvement of adjacent structures and evidence of distant metastasis. Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) are first line. Computed tomography (CT) with pancreatic protocol is an alternative in patients whom MRIs are contraindicated. Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) should be used to assess cysts with malignant features including large size, dilation of the main pancreatic duct and/or presence of a solid component. Cystic fluid cytology can be assessed to look for atypical or malignant cells. Fluid markers especially carcinoembryonic antigen (CEA) can help with the diagnosis as well. Cysts with a solid component and a dilated pancreatic duct or have malignant features on EUS and FNA should undergo surgical resection. Cysts with no concerning features should be monitored with MRIs.[13][14]

Surgery is inidcated in patients with IPMNs and high-grade dysplasia or IPMNs that have progressed to invasive carcinoma. Surgery is recommended for all mucinous neoplasms and main duct neoplasms. In cases of branch duct cysts, observation may be elected. For patients with invasive ductal adenocarcinoma of the pancreas, postresection adjuvant therapy improves survival, even in patients with positive margins or involved lymph nodes. There is controversy as to the best adjuvant strategy. Due to the significant morbidity and mortality associated with pancreaticoduodenectomy or distal pancreatectomy, the patient's and surgeon's decision to perform surgery should include factors such as the patient's age and general health, the malignant risk of the lesion, and the suspicion for malignancy. Cysts not meeting criteria for resection are typically followed with surveillance imaging [15].

If the main duct is greater than or equal to 1.5 cm, suitable patients should undergo surgical resection. If the whole duct is affected, then total pancreatectomy is the treatment of choice. If the head of the pancreas is affected, then Whipple's procedure (pancreaticoduodenectomy) is the operation of choice. If the tail of the pancreas is affected, then distal pancreatectomy plus or minus splenectomy may be warranted.

Differentials include pancreatic pseudocysts, serous cyst tumors, mucinous cyst neoplasms and solid pseudopapillary neoplasms. Imaging including MRI, MRCP and EUS with FNA helps in the differentiating IPMNs from other types of cysts.

For operative technique, an upper midline incision is made, once, inside the abdomen, entrance to lesser sac is created with harmonic scalpel. Kocherization of the duodenum performed. Once the pancreas is identified, the tissue is dissected where the IPMN is involved. As much as possible, the pancreatic parenchyma should be preserved to ameliorate the side effects of diabetes mellitus and exocrine insufficiency secondary to missing pancreatic tissue. One trick for intraoperative surgery is to palpate the duct of the pancreas. If it feels dilated, then it has to be resected as it needs to be assumed that it is dilated due to increased mucin production (abnormal). Confirm negative margins with a frozen section by sending to pathology.

There is no role for radiation in the management of IPMNs.

No indication for chemotherapy for IPMN as it is considered a premalignant condition. Currently, surgery is the mainstay of therapy. If invasive cancer component identified after surgery then we need adjuvant chemotherapy. The chemotherapy would be Gemcitabine, or Gemcitabine plus Capecitabine or modified FOLFIRINOX for 6 months

Staging needs to be completed with CT of the chest, abdomen, and pelvis with intravenous contrast.

The 5-year survival for IPMNs is about 45% to 50% in comparison to pancreatic adenocarcinoma's 5-year survival of 30% [1].

After surgery, complications such as bleeding, anastomotic leak, abscess, or death can occur. Pancreatic enterocutaneous fistulas are a dreaded complication of pancreatic surgery for which to be aware. Typically, these are treated with total parenteral nutrition (TPN), nothing by mouth, and drainage and possibly somatostatin analogues [16].

Early ambulation is recommended postoperatively. Drain placed at surgery should be removed after the oral diet is advanced and the patient tolerates a regular diet without increase of drain output. If there is suspicion for a pancreatic fistula, fluid should be tested for amylase and lipase which are expected to be elevated. 

Physical therapy, occupational therapy and nutritional consultations may be suggested.

Patients need diabetes education. The patient needs to closely follow up with his primary care provider for diabetes management and prevention. Patients who smoke need to be given resources to quit smoking.

Patients should undergo follow up surveillance every 6 months for a year after the surgery with CT scans of the abdomen. If by 1 year nothing is seen, then patients can follow up annually and have imaging with MRCP to reduce radiation exposure.

Management of IPMNs require an interprofessional team consisting of an oncology nurse, oncologist, surgeon, and pharmacist specializing in oncologic medications. The patient will require regular follow-ups by the team for best results. [Level V]