Pancreatic serous cystadenoma masquerading as malignancy

Area of Science:

• Gastroenterology
• Oncology
• Radiology

Background:

• Pancreatic cysts present a diagnostic challenge due to overlapping features of benign, premalignant, and malignant lesions.
• Serous cystadenomas, while benign, can mimic other pancreatic neoplasms, complicating preoperative diagnosis.
• Differentiating these lesions preoperatively is crucial for appropriate patient management.

Purpose of the Study:

• To describe a challenging case of pancreatic cyst misdiagnosis.
• To highlight the difficulties in differentiating serous cystadenoma from pancreatic neuroendocrine tumors using multimodal investigations.
• To emphasize the importance of histopathological confirmation in pancreatic cystic lesions.

Main Methods:

• Case report of an elderly female with an incidentally detected pancreatic tail mass.
• Utilized 18F-fluorodeoxyglucose positron emission tomography (PET), magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS).
• Investigated with chromogranin-A, urinary 5-hydroxyindoleacetic acid, and gallium-68 PET; fine needle aspiration (FNA) was performed.

Main Results:

• Multimodal investigations yielded discordant findings, raising suspicion for pancreatic neuroendocrine tumor despite imaging favouring serous cystadenoma.
• Chromogranin-A and urinary 5-hydroxyindoleacetic acid were slightly elevated, with gallium-68 PET suggesting somatostatin receptor expression.
• Histopathology after robotic distal pancreatectomy and splenectomy confirmed a benign serous cystadenoma.

Conclusions:

• This case underscores the diagnostic complexities associated with pancreatic cystic lesions.
• Conflicting results from various imaging modalities can occur, necessitating careful interpretation.
• Histopathological analysis remains the gold standard for definitive diagnosis of pancreatic cysts.