Pancreatic cysts are, in most cases, incidental findings from 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 of the pancreas can be divided into:
- benign cysts: pseudocysts, simple cysts, serous cystadenomas
- malignant cysts: cystadenocarcinomas, cystic neuroendocrine tumors, solid 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 appearance (70% of SCAs). In about 20-30% of cases, the septa converge to the center of the lesion, forming a central fibrous scar (the most typical sign of SCA). In 20% of cases, we observe a honeycomb appearance, with multiple microcysts and thin septa between them.
Figure 1: Serous Cystadenoma of the head of the pancreas – lobular lesion with septa converging to the central location of the lesion. (personal archive)
In about only 10% of cases, SCAs can be oligocystic, making the radiological diagnosis more challenging. In these cases, other exams are often necessary for diagnostic confirmation, such as Endoscopic Ultrasound with fine-needle aspiration and analysis of the intracystic fluid.
Fluid characteristics
The cytological characteristic of serous cystadenoma is 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 Carcinoembryonic Antigen (CEA) below 192 ng/ml, which is associated with non-mucinous lesions. In addition, since there is no communication with the pancreatic ducts, the amylase in the intracystic fluid is low.
More recently, with the advancement of confocal endoscopy, it is possible to visualize the pattern of vascularization (in SCAs, 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 greater risks of adverse effects (acute pancreatitis and intracystic hemorrhage).
Prognosis
The prognosis of SCAs is excellent, with less than 1% mortality. Few cases in the literature have evolved to malignancy, and there is no agreement on the frequency 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 growth of the lesion in up to 40% of SCAs.
The latest recommendation from the European group is for a new imaging exam in 1 year, and subsequently, only if there are symptoms (abdominal pain, jaundice, or nausea and vomiting).
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
How to cite this article
Marzinotto, M. SEROUS CYSTADENOMA OF THE PANCREAS. Endoscopy News 2024. Available at: https://endoscopy.news/general-topics/serous-cystadenoma-of-the-pancreas/
Medica responsável pelo Grupo de Pâncreas da Disciplina de Gastroenterologia Clínica do HCFMUSP