A disseminated variant of pancreatic serous cystadenoma causing obstructive jaundice, a very rare entity: a case report and review of the literature

Microcystic adenoma or serous cystadenoma (SCA) of the pancreas is an uncommon, benign tumor that accounts for 1–2% of pancreatic exocrine neoplasms and 25% of cystic neoplasms [1]. Their prevalence is increasing, primarily due to imaging technique improvements. These tumors are usually unifocal, mostly arising in the body and tail of the pancreas and are often incidentally detected. They present as single, large, well demarcated, and multiloculated cystic tumors, 1–25 cm in size. They are composed of cysts lined by epithelial cells that produce serous fluid and show ultrastructural evidence of centroacinar differentiation [2].

The World Health Organization (WHO) has subclassified these tumors into two groups, serous microcystic adenomas and serous oligocystic adenomas. The serous microcystic adenoma is a well-demarcated tumor composed of numerous small cysts arranged around a central stellate scar. The central stellate scar is a dense fibrous core within the tumor, which may be calcified and from which fibrous trabeculae radiate to the periphery. The serous oligocystic adenoma is an often ill-demarcated tumor composed of a few cysts with diameters of 1–2 cm. Serous cystic tumors showing larger cysts have been referred to as serous macrocystic adenomas [3]. A third type, the disseminated variant (DV), has been recognized because of its rare involvement of the entire pancreas. In the DV, both of the previously described types are spread throughout the pancreas. Although DVs are rare, they are more commonly reported in association with Von Hippel-Lindau (VHL) disease [4]. VHL disease, which is an autosomal dominant condition having variable penetrance, is characterized by central nervous system (CNS) and retinal hemangioblastomas, visceral cysts, pheochromocytomas, and renal cell carcinoma; pancreatic lesions are seen in approximately 56% of VHL patients [4]. Criteria for the diagnosis of VHL include the presence of a CNS hemangioblastoma with at least one other VHL-type lesion in an individual or one VHL-type lesion in a family member if another family member has a CNS hemangioblastoma [4].

Here, we present a rare case of a pancreatic SCA involving the whole pancreas ( DV) that caused obstructive jaundice, with no association with VHL.

SCAs are benign cystic tumors composed of cuboidal epithelium and producing serous fluid [3]. Although rare cases of serous cyst adenocarcinoma have been reported [5], the WHO reported that the prevalence of malignant pancreatic SCAs is 1–3% [5]. This malignant variant is defined by the presence of metastases in extrapancreatic organs or tissues [5]. In addition, the presence of invasion to the adjacent organs is considered a characteristic of malignancy [6]. SCAs predominate in females in their sixth decade of life [7] and are asymptomatic in 33% of cases [7]. Symptoms are frequently non-specific, with abdominal pain being the most common, occurring in 50–60% of all cases [7]. The tumors rarely cause obstructive jaundice [6, 8–12] and are usually unifocal, situated in the body and tail of the pancreas, and are multiloculated and cystic in appearance. The present case can be classified as one of a multicentric serous tumor involving the entire pancreas with almost complete obliteration of pancreatic acini and ducts.

Differentiation of SCAs from mucinous cystadenomas and pseudocysts is usually based on ultrasonography or CT findings. When the distinction is less clear, fine-needle aspiration of the cystic lesions for cytology and biochemical analysis of the fluid may help in establishing the diagnosis. On cytological analysis, periodic acid-Schiff stains of SCAs show abundant cytoplasmic glycogen, and stains for mucin are negative [21]. Cells are cuboidal to polygonal in shape, without evident mitoses; cytological analysis is diagnostic in about 20% of cases [22]. Biochemical analysis of cyst fluid may include tests for amylase and some tumor markers, such as carcinoembryonic antigen, NB/70K, CA 72–4, CA 125, CA 15–3 tissue polypeptide antigen, and pS2 protein [23, 24]. The amylase content of the fluid in SCAs is usually lower than the levels in pseudocysts and mucinous cystic tumors, and SCAs have lower levels of tumor markers compared with mucinous cystic tumors.

Most authors advise that asymptomatic patients be closely monitored, so long as potentially malignant cystic tumors, mainly mucinous cystadenoma or intraductal papillary mucinous tumor, can be definitively excluded. Surgical intervention is indicated for patients with symptomatic lesions and those with an uncertain diagnosis [25, 26]. Size of the cyst at presentation is still debatable since some reports indicate resection for cysts >4 cm and others do not [27].

Recently published guidelines for cystic pancreatic management suggest that resection should be considered for all symptomatic cases of SCA, for patients with cysts >4 cm, in case of presence of mural nodules, dilatation of main pancreatic duct >6 mm, increased serum levels of carbohydrate antigen (CA 19–9), or in case of rapid increase in size [28, 29].

In conclusion, SCAs of the pancreas are increasing in frequency of diagnosis because of advances in imaging techniques. The differentiation of SCAs from other cystic tumors, as well as from non-neoplastic cysts, is very important because of the great differences in the management of these different entities. This case highlights an extremely rare case of SCA involving the whole pancreas (DV) causing obstructive jaundice, without an association with VHL disease.

Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.