| Abstract|| |
Serous cystadenoma is a rare benign cystic lesion of pancreas. They are mostly known as benign cystic tumors of pancreas but malign transformation as serous cystadenocarcinoma is also reported. It is more commonly observed in women with the mean age of onset is 62 years. The majority of patients present nonspecific symptoms such as abdominal pain, weight loss, nausea, vomiting, fever, and melena. One-third of the patients are asymptomatic. A 60-year-old woman presents with abdominal pain and nausea for 1 month was admitted. Physical and laboratory findings were normal. Abdomen computed tomography scan confirmed a large number of millimetric cysts of 45 × 47 × 50 mm in size at the head of the pancreas. Due to patient's symptoms and mass effect, Whipple procedure was performed. In the gross examination, a nodular area of 5 × 5 × 4 cm was observed in the head of the pancreas. The microscopic examination of the material revealed cystic structures with fibrous stroma dotted with single layered cuboidal epithelium in the pancreatic tissue. The pathology report confirmed benign macrocystic serous cystadenoma. Serous cystadenomas are rare benign cystic lesions of the pancreas. Although they are benign lesions, it is crucial to differentiate them from other cystic lesions of the pancreas and malignant serous cystadenocarcinomas.
Keywords: Benign tumor, macrocystic, pancreas, serous cystadenoma
|How to cite this article:|
Duzcu SE, Tunc N. Benign macrocystic serous cystadenoma of the pancreas. Indian J Pathol Microbiol 2021;64, Suppl S1:166-8
| Introduction|| |
Serous cystadenoma is a rare benign cystic lesion of pancreas composed of glycogen rich uniform epithelial cells containing innumerable serous fluid filled cysts. Serous cystadenomas are more frequently seen in women (approximately 75% of all cases). The mean age of patients who underwent pancreatic surgery for serous cystadenoma was 56 years in Europe, 58 years in Asia, and 62 years in the USA. While most of the cases present with nonspecific symptoms such as abdominal pain, nausea, and vomiting, they can also be detected incidentally during radiological imaging methods for any reason. Serous cystadenomas are most frequently seen in the head of the pancreas (39%), while they are observed in varying degrees in the trunk (35%), tail (22%), and uncinate process (3%). Most serous cystadenomas usually manifest itself as a large multilocular lesion lined by normal tissue in gross examination. Although the size of the cystic lesion varies from 1 cm to 6 cm in average, there can be cases up to 25 cm in size. Cysts larger than 2 cm are rarely seen., Although the majority of serous cystadenomas show microcystic growth pattern, they are rarely macrocystic. Macrocystic serous cystadenomas composed of fewer but larger cysts than the microcystic growth pattern.
In this study, we present a case of macrocystic serous cystadenoma detected in a patient who had complaints of abdominal pain and nausea and diagnosed with a cystic mass in the pancreas during an abdominal imaging. By reviewing the literature, the criterion of malignancy and differential diagnosis of cystic lesions of the pancreas were discussed.
| Case Presentation|| |
A 60-year-old woman presents with abdominal pain and nausea for 1 month was admitted to the Department of General Surgery. Physical examination of the patient revealed widespread abdominal discomfort. The patient had no history of smoking and alcohol use. She had hypertension for 20 years and diabetes mellitus for 4 years. Complete blood count, biochemical parameters, and CA 19-9 were in normal values. The abdominal contrast computed tomography examination of the patient revealed the normal pancreatic size and heterogeneous parenchyma. At the head of the pancreas, a large number of milimetric cysts of 45 × 47 × 50 mm and dilated wirsung duct of 14.5 mm diameter containing calcifications and a complex cystic mass causing atrophy in the pancreas was observed. Due to the cystic lesion of the pancreas, the patient underwent through Whipple procedure.
In the gross examination of Whipple operation material, a nodular area of 5 × 5 × 4 cm was observed in the head of the pancreas. A large number of honeycomb-like cystic structures filled with clear liquid of different sizes were observed in the cross sections of this area [Figure 1].
|Figure 1: A large number of honeycomb-like cystic structures filled with clear liquid of different sizes|
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The microscopic examination of the material revealed cystic structures with fibrous stroma dotted with single layered cuboidal epithelium in the pancreatic tissue. Multiple epithelial cysts of various sizes separated by fibrocollagenous septa were seen. Atypia was not present in cyst epithelium [Figure 2]a,[Figure 2]b. Fibrosis, neuroendocrine hyperplasia, and mild lymphocyte infiltration were observed in other areas of the pancreatic tissue. Cystic structures were found to be limited to the pancreas.
|Figure 2: (a) Multiple epithelial cysts of various sizes separated by fibrocollagenous septa (H&E ×200). (b) Cystic structures with single layered cuboidal epithelium in the pancreatic tissue (H&E ×200). (c) Positive staining of cyst epithelium with MUC-1 (×100). (d) Positive staining of cyst epithelium with CK19 (×100)|
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Immunohistochemical study showed positive staining of cyst epithelium with MUC-1, CK7, CK19. There was a weak positivity with neuron-specific enolase (NSE). CD34, MUC-2 and MUC-5AC showed negative staining [Figure 2]c,[Figure 2]d.
Therefore, when histochemical and immunohistochemical findings were evaluated, this case was reported as “Benign Macrocystic Serous Cystadenoma.”
| Discussion|| |
Serous cystic neoplasms are the largest subgroup which constitute approximately 30% of the primary cystic neoplasms of the pancreas. Malignant serous cystadenocarcinomas constitute only 1–3% of the serous tumors of the pancreas.
Serous cystadenomas originate from acinar cells are benign cystic tumors of pancreas. It is more commonly seen in women with the mean age of onset of 62 years.
The majority of patients present with nonspecific symptoms such as abdominal pain, weight loss, nausea, vomiting, fever, and melena. One-third of the patients are asymptomatic. In this case, a 60-year-old female patient with abdominal pain and nausea for 1 month admitted to the hospital.
The diagnosis of serous cystadenoma is mainly based on imaging techniques such as ultrasonography (USG), computed tomography (CT), and endoscopic ultrasonography (EUSG). While it may occur in any part of the pancreas, it is more common in the head. Serous cystadenomas consist of multiple cysts separated by thin septas and often exhibit honeycomb-like appearance in imaging modalities. The presence of central scar with calcification is pathognomonic in CT, however it only occurs in 30% of patients. There is increased contrast enhancement of septa in contrast-enhanced CT. In this case report, the radiological examinations revealed a septated multi-layered cystic lesion with lobulated contour, showing increased enhancement in septa and containing multiple millimetric calcifications at the head of the pancreas.
According to the classification of the World Health Organization (WHO), these more commonly seen tumors defined in two groups as serous microcystic adenoma and serous oligocystic adenoma. Serous microcystic adenomas are well-limited lesions consisting of a large number of small cysts located around the central scar. Serous oligocystic adenomas are frequently well-circumscribed lesions consisting of several cysts with diameters ranging from 1 to 2 cm. Serous cystic lesions showing larger cysts are called as serous macrocystic adenomas. The cysts may extend deeply into the pancreatic tissue. Serous macrocystic adenomas are rare and have fewer large cysts. Cysts are usually greater than 1 cm. They usually occur at the head of pancreas and cause obstructive symptoms because they are larger in size. In this case the largest diameter of the cystic lesion was 5 cm.
Serous cystadenocarcinomas, the malignant form of serous cystic lesions, have been reported in recent years., In reported cases, in contrast to serous cystadenomas, the cystadenocarcinoma patients show slight nuclear pleomorphism, nuclear atypia, and perineural invasion in tumor cells while other histological and immunohistochemical features are similar to serous cystadenomas. The presence of distant metastases to organs such as liver, spleen, colon, and stomach support the diagnosis of serous cystadenocarcinomas.
Serous cystadenomas may be present alone or in association with pancreatic endocrine tumors, dorsal pancreas anomaly, pancreatic divisum, and other pancreatic anomalies., There were no such association in this case.
The differential diagnosis of serous cystadenomas from pseudocysts and other cystic lesions is very crucial due to its different treatment protocols. Although serous oligocystic adenomas may be confused with mucinous cystadenoma and pseudocysts, the average age of patients with pseudocysts is generally higher, more common in men, and usually have a history of previous pancreatitis or trauma. Although endoscopic retrograde pancreaticography performed in 70% of pseudocyst cases shows the relationship between pseudocyst and pancreatic duct, there is no such relation in serous cystadenomas. It is important to show intratumoral calcification of serous cystadenomas in the differential diagnosis of mucinous cystadenoma and pseudocysts in radiological imaging methods.
In the treatment of serous cystadenomas, patient's symptoms, the accuracy of the preoperative diagnosis, the safety of the resection, and the risks of conservative treatment play an important role. Most symptomatic patients undergo pancreatic resection. Drainage of these tumors is not suitable. Lesions in the body and tail of the pancreas require distal pancreatectomy. Whipple resection is the preferred surgical method for patients with lesions located in the uncinate process and head of the pancreas. Serous cystadenomas are almost always benign. Therefore, some authors suggest closer follow-up for the asymptomatic patients with non-occluded canal or vessels and elderly patients with operational risks. However, conservative treatment may allow the development of complications such as rapid tumor growth, bleeding, gastrointestinal, or biliary obstruction. In this case, Whipple procedure is performed due to the location of the lesion on the head of the pancreas, size of the lesion and presence of symptoms in the patient.
In conclusion, serous cystadenomas are rare benign cystic lesions of the pancreas. Although they are benign lesions, it is crucial to differentiate them from other cystic lesions of the pancreas and malignant serous cystadenocarcinomas.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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Department of Pathology, Abant Izzet Baysal University
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2]