Serous cystic neoplasms

Serous cystic neoplasms occur more frequently in middle-aged women. Any portion of the pancreatic gland can be affected. They are almost always benign lesions, as only a very small number of malignant variants (serous cystoadenocarcinomas) has been described.

The majority of serous cystic neoplasms are asymptomatic and thus incidentally discovered. When present, the most common symptom is abdominal discomfort or low-grade pain. Weight loss, palpable mass, jaundice, and obstructive pancreatitis uncommon.

The diagnosis is easy when the lesion displays the characteristic microcystic pattern (honeycomb-like), consisting in multiple cysts measuring 2 cm or smaller separated by fibrous septa that may coalesce into a central scar. The oligocystic variant (small number of cysts greater than 2 cm) and the macrocystic variant (single cyst) lack proper characterization on cross-sectional imaging, and may represent a source of diagnostic uncertainty. In these cases, differentiation with mucin-producing neoplasms may be challenging. On occasion, the cysts may be tiny such that the neoplasm appears radiologically solid.
 
In our experience, magnetic resonance imaging with cholangio-pancreatography is the most accurate imaging modality; instead, endoscopic ultrasound seems to be the only technique able to supply further information when the diagnosis is unclear. In this regard, analysis of the cyst fluid for CEA helps in differentiating mucinous from serous cysts.
 
Resection is generally carried out:
  • in symptomatic patients 
  • when the tumor cannot be distinguished from mucin-producing cystic neoplasms
  • in very large or rapidly growing lesions

In surgical candidates, minimally invasive, parenchyma-sparing resections may be proposed. For more information on minimally invasive pancreatic surgery click here.

Well-documented asymptomatic lesions can be managed non-operatively. A recent study from our institution of 145 patients with serous cystic neoplasms enrolled in a surveillance protocol with magnetic resonance imaging showed that the overall mean growth rate was slow, at 0.28 cm/year. The oligocystic/macrocystic variant, a personal history of other non-pancreatic malignancies, and patient age were demonstrated to impact on tumor growth. Tumor size at the time of diagnosis was not a predictor of growth and therefore should not be used for decisional purposes. 

 

Learn more:

Malleo G, et al. Gut. 2012;61:746-751.

Khashab MA, et al. Am J Gastroenterol. 2011;106:1521-1526.