Pancreatic cysts are, in most cases, incidental findings of imaging exams.
It is estimated that about 3-14% of people undergoing abdominal exams have some pancreatic cystic lesion as a finding. In autopsy studies, this finding can reach 24%. There is a clear increase in prevalence in older age groups.
Cystic lesions can be divided into:
- benign cysts: pseudocysts, simple cysts, serous cystadenomas
- malignant cysts: cystadenocarcinomas, cystic neuroendocrine tumors, solid-cystic pseudopapillary neoplasia
- cysts with potential for malignancy: IPMNs and mucinous cystadenomas
In this article we will talk a little about serous cystadenoma.
SEROUS CYSTADENOMA (SCA)
Serous cystadenoma is a lesion that affects more women than men (2:1), in the 6th or 7th decade of life.
It is a lesion that has no preference for any pancreatic region, being able to affect the head, body or tail of the gland.
Radiological aspect
The most striking characteristic of serous cystadenoma is the finding of a polycystic lesion, with fibrous septa between them, forming a microcystic aspect (70% of SCA). In about 20-30% of cases, the septa converge to the center of the lesion, forming a central fibrous scar (most typical sign of SCA). In 20% of cases we observe a honeycomb aspect, with multiple microcysts and thin septa between them.
Figure 1: Serous Cystadenoma of the pancreas head – lobular lesion with septa converging to the central location of the lesion. (personal file)
In about only 10% of cases SCA can be oligocystic, making the radiological diagnosis more challenging. In these cases, other exams are often necessary for diagnostic confirmation, such as Echoendoscopy with puncture and analysis of the intracystic fluid.
Fluid characteristics
The cytological characteristic of serous cystadenoma are cuboidal cells, with cytoplasm rich in glycogen, although the sensitivity for cytology with FNA is very low.
The biochemical analysis of the fluid can help in cases of uncertain diagnosis. The characteristic of SCA is to have the Carcino-Embryonic Antigen (CEA) below 192 ng/ml, which is associated with non-mucinous lesions. In addition, as there is no communication with the pancreatic ducts, the amylase in the intra-cystic fluid is low.
More recently, with the advancement of confocal endoscopy, it is possible to visualize the vascularization pattern (in SCA, it is subepithelial – accuracy 87%) and allows biopsies of the cyst epithelium. This procedure is still performed in few centers, and although it improves the accuracy of the diagnosis, it brings higher risks of adverse effects (acute pancreatitis and intracystic hemorrhage).
Prognosis
The prognosis of SCA is excellent, with less than 1% mortality. Few cases in the literature have evolved to malignancy, and there is no agreement on the periodicity of follow-up. For many authors, it is a benign lesion.
Although it is a lesion with a low chance of malignant transformation, there is the possibility of lesion growth in up to 40% of SCAs.
The last recommendation from the European group is for a new imaging exam in 1 year, and afterwards, only if there are symptoms (abdominal pain, jaundice or nausea and vomiting).
How to cite this file
Marzinotto M., SEROUS CYSTADENOMA OF PANCREAS. Gastropedia, 2022. Available at: https://gastropedia/gastroenterology/pancreas/serous-cystadenoma-of-pancreas
References
- Sakorafas, GH et al. Primary pancreatic cystic neoplasms revisited. Part I: Serous cystic neoplasms. Surgical Oncology, 2011
- Tirkes, T et al. Cystic neoplasms of the pancreas; findings on magnetic resonance imaging with pathological,surgical, and clinical correlation. Abdom Imaging, 2014
- Larson, A et al. Natural History of Pancreatic Cysts. Dig Dis Sci, 2017
Medica responsável pelo Grupo de Pâncreas da Disciplina de Gastroenterologia Clínica do HCFMUSP
