Schwannoma mimicking pancreatic carcinoma: A case report

Abstract

BACKGROUND Schwannoma of the pancreas is extremely rare. We report a case of pancreatic schwannoma that was difficult to distinguish from pancreatic carcinoma before surgery. CASE SUMMARY A 66-year-old male underwent a right-lobe hepatectomy for hepatocellular carcinoma. Post-surgical computed tomography showed a 10 mm long solid mass with ischemia, with no expansion into the main pancreatic duct. Upon magnetic resonance cholangiopancreatography, the tumor had high signal intensity in diffusion weighted images, consistent with pancreatic carcinoma. Endoscopic ultrasound (EUS) was performed to obtain more information about the tumor, and showed a 14 mm solid and hypoechoic mass in the pancreatic body. Contrast enhanced EUS revealed that the tumor showed a hyperechoic mass in the early phase, and the contrasting effect continuation was very short; findings also consistent with pancreatic carcinoma. Thus, we preoperatively diagnosed his condition as a pancreatic carcinoma and performed distal pancreatectomy with splenectomy. Microscopic examination showed that the tumor was in fact a benign schwannoma. Histology showed a proliferation of spindle-shaped cell in a vague fascicular and haphazard pattern, with palisading arrangement. CONCLUSION Schwannoma of the pancreas is very rare, however, clinicians should consider schwannoma as the differential diagnosis for pancreatic tumors.

Pancreatic schwannoma: a rare tumor of the pancreas

“…Schwannomas are rarely detected in the pancreas (1), and the majority of cases have been reported to be benign, with <1% transforming into malignancy (2,3,4). They tend to occur in adults, with slightly higher incidence in women than in men (2).…”

“…They tend to occur in adults, with slightly higher incidence in women than in men (2). The clinical symptoms of schwannomas are nonspecific, and tumor marker test is often negative (2,3). Although an accurate preoperative diagnosis helps in avoiding an unnecessary radical resection, endoscopic ultrasonography, or percutaneous biopsy (4), it is difficult to achieve (2,3,4).…”

“…The clinical symptoms of schwannomas are nonspecific, and tumor marker test is often negative (2,3). Although an accurate preoperative diagnosis helps in avoiding an unnecessary radical resection, endoscopic ultrasonography, or percutaneous biopsy (4), it is difficult to achieve (2,3,4). Radiologically, schwannomas are wellcircumscribed masses displaying inhomogeneous intensity or density with heterogeneous enhancement by increased fluorodeoxyglucose uptake and are frequently confused with nonfunctioning endocrine neoplasms, solid pseudopapillary neoplasms, pancreatic ductal adenocarcinoma, and mucinous cystic neoplasms (1,2,3,4).…”

“…Although an accurate preoperative diagnosis helps in avoiding an unnecessary radical resection, endoscopic ultrasonography, or percutaneous biopsy (4), it is difficult to achieve (2,3,4). Radiologically, schwannomas are wellcircumscribed masses displaying inhomogeneous intensity or density with heterogeneous enhancement by increased fluorodeoxyglucose uptake and are frequently confused with nonfunctioning endocrine neoplasms, solid pseudopapillary neoplasms, pancreatic ductal adenocarcinoma, and mucinous cystic neoplasms (1,2,3,4). Histologically, schwannomas contain various proportions of Antoni A (hypercellular component) and Antoni B (hypocellular component), expressing S-100 protein (1,2,3,4).…”

Successful treatment of pancreatic schwannoma by enucleation

“…However, pancreatic schwannomas are rare. To the best of our knowledge, only 96 cases of pancreatic schwannomas have been reported in the English literature over the past 50 years [4–83] . Most patients are asymptomatic, and the tumor is incidentally found.…”