Mucinous Cystic Neoplasm (MCN) of Pancreas

A woman in her 8^th decade presented with 2 months history of dull aching pain in the upper abdomen.  She was in good health and there was no serious comorbidity though she had hypertension that was well controlled on medication. Her physical examination was unremarkable except for obesity (BMI 31kg/m²). An initial abdominal ultrasound done elsewhere was suggestive of large cystic lesion in the body of pancreas.

The patient was further investigated with contrast enhanced abdominal magnetic resonance imaging (MRI) of the abdomen which showed a well defined, large (> 5 cm) unilocular cystic lesion with thick enhancing capsule located centrally in the body of pancreas. There was no duct – cyst communication (Figure 1 & 2).

Figure 1

Figure 2

A diagnosis of mucinous cystic neoplasm (MCN) was made. A subsequent endoscopic ultrasound revealed a large multiseptated cyst with solid components in the pancreatic body raising the possibility of mucinous cystadenocarcinoma. The cyst fluid CEA was 47788 IU.

In view of large, centrally placed lesion, a hybrid procedure i.e. laparoscopy assisted lateral to medial mobilization of pancreas and spleen with open transection of the pancreas was proceeded with. The postoperative period was uncomplicated.

At histopathology there was 7x5 cm MCN with low grade dysplasia.

The patient is well 3 years after surgery

Discussion

1.       Pseudocyst or MCN

2.       Surgery for MCN

These are sequentially discussed below:

1.       Pseudocyst or MCN: Prior to any intervention for cystic tumors of the pancreas, pseudocyst needs to be conclusively ruled out. In patients where doubt persists after all investigative modalities have been utilized it is best to follow the surgical dictum ‘it is better to resect a pseudocyst than to drain a cystic tumor’. The salient features for differentiating MCN and  pseudocyst are summarized in table 1

Table 1. Pseudocyst versus MCN¹

Parameter	MCN	Pseudocyst
History of acute pancreatitis	Absent. (c.f. 10% patient may present with acute pancreatitis)2,3	Present
Contrast MRI with MRCP	Cyst wall enhancing Main pancreatic duct – cyst communication absent (Figure 3)	Cyst wall nonenhancing Main pancreatic duct – cyst communication present (Figure 4)
EUS guided cyst fluid aspiration	Cyst fluid amylase – CEA  +++	Cyst fluid +++ CEA -

 

Figure 3. Main pancreatic duct – cyst communication absent

Figure 4. Main pancreatic duct – cyst communication present

2. Mucinous cystic neoplasms are characterized by presence of ovarian stroma and lack of communication with main pancreatic duct.² They occur most frequently in women (95%), in distal pancreas (97%) and are always a single lesion.³ The risk of malignancy is reported to be 17%.² The clinical and imaging parameters associated with malignancy include older age, presence of mural nodules and cyst diameter of ≥ 60 mm.²

Resection should be considered in all patients with MCN.² This is most commonly in the form of distal pancreatectomy. In low risk MCN (≤ 4 cm, no mural nodules) non radical resections are appropriate

References

1.       Singhal D, Kakodkar R, Sud R et al. Issues in management of pancreatic pseudocysts. JOP 2006;7(5):502-7

2.       Crippa S, Salvia R, Warshaw AL et al. Mucinous cystic neoplasm of the pancreas is not an aggressive entity: lessons from 163 resected patients. Ann Surg 2008;247(4):571-9

3.       Farrell JJ, Castillo F. Pancreatic cystic neoplasms: management and unanswered questions Gastroenterology 2013;144:1303-15

Authors:

Dr Nitin Vashistha, MS, FIAGES, FACS

Dr Dinesh Singhal, MS, FACS, DNB (Surg Gastro)

Department of Surgical Gastroenterology,
Max Super Speciality Hospital, Saket, New Delhi, India
E mail: gi.cancer.india@gmail.com

www.gicancerindia.com

Serous Oligocystic Cystadenoma (SOA)

A 50 year lady presented with history of dull ache in left upper abdomen of 2 months duration. Her abdominal examination was unremarkable. The abdominal ultrasound was suggestive of cystic lesion in the body and tail of pancreas. The carbohydrate antigen 19-9 (CA 19-9) was 21 units/milliliter. Her other hematological & biochemical parameters were within prescribed normal range.  Subsequently she underwent abdominal contrast enhanced computed tomography (CT) scan and then magnetic resonance cholangiopancreatography (MRCP) and contrast enhanced magnetic resonance imaging (MRI) scan (Figure A, B & C).   In view of the typical imaging findings (vide infra) a diagnosis of SOA was made.

Figure A: Contrast enhanced abdominal computed tomography scan

Figure B: Contrast enhanced abdominal magnetic resonance imaging scan

Figure C: Magnetic Resonance Cholangio-Pancreatography 

In line with current recommendation for surgery for pancreatic serous cystadenoma, resection was proceeded with due to symptomatic, large (> 4 cm) tumor.¹

The patient underwent laparoscopy assisted distal pancreatectomy with splenectomy. At laparoscopy there was a large (approximately 9 x 7cm) multiloculated exophytic tumor in the body and tail region of pancreas that was adherent to the mesocolon and left branch of the middle colic artery (Figure D). She had an uncomplicated postoperative period and was discharged on 8^th day following surgery. Histopathology revealed cysts lined by single layer of cuboidal epithelial cells filled with clear cytoplasm.

Figure D: Distal pancreatectomy + splenectomy specimen showing

multiple thin walled cysts

Discussion

Serous oligocystic cystadenoma is a subgroup of pancreatic serous cystadenoma (SA) characterized by image findings described above.² In comparison with SA, they are uncommon and can sometimes be difficult to diagnose due challenging overlap of image findings with other cystic lesions.

In the following sections, we present differentiating features with other pancreatic cystic neoplasms:

A.      Solid pseudopapillary neoplasm (SPN)

B.      Branch chain intraductal papillary mucinous neoplasm (IPMN)

C.      Mucinous cystic neoplasm (MCN)

In our patient, the contrast enhanced abdominal computed tomography scan shows a lobulated cystic neoplasm with septations in the body and tail of pancreas with thin (< 2 mm) non enhancing walls. The cystic spaces (6 in number) are > 2 cm (Figure A). These findings are better appreciated in contrast enhanced abdominal magnetic resonance imaging scan (Figure B). At magnetic resonance cholangio-pancreatography (MRCP), the main pancreatic duct (MPD) is not dilated in its entire course and there was no duct – cyst communication (Figure C). Hence a diagnosis of SOA was made.³

Mucinous cystic neoplasms usually are unilocular or mildly septated and have a smooth contour.^3,4 The cyst wall is thick and enhances at contrast enhanced MR imaging.⁴

Branch chain IPMN was ruled out as the MPD was of normal caliber at MRCP and the cystic tumor did not have communication with the main pancreatic duct (Figure B).

Solid pseudopapillary neoplasms typically appear in young women and on contrast enhanced abdominal CT or MRI scan appear as well defined, encapsulated, heterogeneous solid and cystic tumor with areas with hemorrhagic degeneration.⁵ These findings are not consistent with those in Figures A and B from our patient. Therefore SPN was also ruled out.

References

1.       Tseng JF, Warshaw AL, Sahani DV et al. Serous Cystadenoma of the pancreas: tumor growth rates and recommendations for treatment. Ann Surg.2005;242(3):413-419

2.       Lee JH, Kim JK, Kim TH et al. MRI features of serous oligocystic adenoma of the pancreas: differentiation from mucinous cystic neoplasm of the pancreas. Br J Radiol. 2012;85:571-576

3.       Kim SY, Lee JM, Kim SH et al. Macrocystic neoplasms of the pancreas: CT differentiation of serous oligocystic adenoma from mucinous cystadenoma and intraductal papillary mucinous tumor. AJR. 2006;187:1192-1198

4.       Kalb B, Sarmineto JM< Kooby DA et al. MR imaging of cystic lesions of the pancreas. RadioGraphics 2009;29:1749-1765

5.       Cantisani V, Mortele KJ, Levy A et al. MR imaging features of solid pseudopapillary tumor of the pancreas in adult and pediatric patients. AJR. 2003;181:395-401

Authors:

Dr Nitin Vashistha, MS, FIAGES, FACS

Dr Dinesh Singhal, MS, FACS, DNB (Surg Gastro)

Department of Surgical Gastroenterology,
Max Super Speciality Hospital, Saket, New Delhi, India
E mail: gi.cancer.india@gmail.com

www.gicancerindia.com

Solid Pseudopapillary Tumor / Neoplasm: Pitfalls in Management of Cystic tumor of Pancreas

A 13 year girl presented with history of mild upper abdominal pain of 6 years duration. The pain had increased in intensity for 1 month. However there was no history of use of intravenous analgesics or of hospitalization for pain relief. She was evaluated and diagnosed to have pancreatic pseudocyst and an open cystoenterostomy was attempted elsewhere. However operative findings at exploration precluded internal drainage. She had an uneventful recovery and was subsequently referred to higher center for further management.

On examination at our centre, she was found to be thin built with stable vitals. Abdominal examination was unremarkable except for well healed midline laparotomy scar.

All routine hematologic and biochemical investigations were within the prescribed normal range. A contrast enhanced computed tomography (CECT) scan of the abdomen was performed (Figure 1 & 2).

Figure 1.

Figure 1 of abdominal CECT shows a 6 cm tumour of the body and tail of the pancreas with solid and cystic components. 

Figure 2.

Figure 2 reveals an air pocket in the tumour at the site of previous biopsy.

 In view of young female patient with an indolent history and aforementioned image features, a diagnosis of solid pseudopapillary tumour (SPT) was made and distal pancreatectomy with splenectomy performed (Figure 3). Histopathology was confirmatory of SPT.

Our report reiterates that when managing cystic lesions of pancreas, a careful evaluation of history, biochemical investigations and imaging is essential to differentiate pseudocyst from cystic tumors. In most instances, the latter can be easily identified by an absence of documented episode of acute pancreatitis and cross sectional imaging depicting thick walled multilocular lesion with septae or solid components. Cyst fluid analysis (preferably endoscopic ultrasound guided) may be helpful when doubt exists in diagnosis. The features indicative of PC include high amylase content, inflammatory cytology and tumor markers (CEA, CA19-9, CA 72-4) within the specified normal range.¹

First described by Frantz in 1959, SPT of the pancreas is a rare neoplasm comprising of 1-2% of all pancreatic tumors.² This entity is encountered almost exclusively in young females in their second or third decade with male to female ratio of 1 is to 9. The tumor may be asymptomatic or associated with vague symptoms such as abdominal pain/discomfort, nausea or loss of appetite. Consequently SPTs often attain large size (3-16cms) by the time a diagnosis is made. At imaging, the characteristic CECT features include a large heterogeneous mass with solid and cystic components and areas of hyperattenuation representing hemorrhage.

With an increased understanding of the biological behavior [low malignant potential (15%) and excellent long-term prognosis in patients with metastatic disease the surgical management of SPTs has evolved over the last decade. The essence of management of primary tumor is on organ preservation. For the tumors in the pancreatic head, pylorus preserving pancreaticoduodenectomy and for the body and tail tumors into a spleen preserving distal pancreatectomy are acceptable procedures. However in patients with large tumors, spleen preservation may not always be feasible. Central resections for body tumors should only be performed at high volume centers. Due to a low incidence of lymph node involvement (<2%) a formal lymphadenectomy is not indicated. The currently available evidence supports metastectomy with 1 cm margin for liver metastases and debulking for peritoneal deposits. Overall 5-year survival is as high as 100% in patients undergoing surgical resection.³ Extended survival is still possible even with extensive disease with debulking surgery.

References

1.       Brugge WR, Lauwers GY, Sahani D, Fernandezdel,Castillo C, Warshaw AL. Cystic neoplasms of the pancreas. N Engl J Med 2004, 351:1218-26

2.       Frantz VK. Papillary tumors of the pancreas: Benign or malignant? Tumors of the pancreas. In: Atlas of Tumor Pathology, Section 7, Fascicles 27 and 28.Washington, DC, USA: Armed Forces Institute of Pathology, 1959:32-3.

3.       de Castro S. M. M, Singhal D, Aronson DC, Busch OR,TM van Gulik, Obertop H, D Gouma et al. Management of Solid-pseudopapillary Neoplasms of the Pancreas: a Comparison with Standard Pancreatic Neoplasms. World J Surg. 2007; 31(5): 1130–1135

Authors:

Dr Nitin Vashistha, MS, FIAGES, FACS

Dr Dinesh Singhal, MS, FACS, DNB (Surg Gastro)

Department of Surgical Gastroenterology,
Max Super Speciality Hospital, Saket, New Delhi, India
E mail: gi.cancer.india@gmail.com

www.gicancerindia.com