A rare pancreatic retention cyst mimicking neoplastic lesions: A case report

Pancreatic cysts are increasingly detected due to the widespread use of high-resolution imaging. These cysts range from benign to malignant and often require careful evaluation to guide management. Differentiating between neoplastic and non-neoplastic cysts remains a diagnostic challenge. Among the non-neoplastic types, pancreatic retention cysts are rare and often under-recognized.

We present the case of an asymptomatic woman in her 50s referred to our oncology center for further investigation of a pancreatic cystic lesion initially discovered incidentally. Imaging follow-up revealed a growth of 2.5 mm in one year. MRI, CT, and endoscopic ultrasound findings, combined with fine-needle aspiration cytology, suggested a mucinous neoplasm-most likely an intraductal papillary mucinous neoplasm (IPMN). The patient underwent distal pancreatectomy with splenectomy. Histopathological analysis revealed a pancreatic retention cyst with no evidence of malignancy.

Retention cysts, though benign, may mimic the radiological and cytological features of IPMNs, leading to overtreatment. This case highlights the importance of integrating clinical, imaging, and histopathological data to reach an accurate diagnosis. The limitations of cytology in cystic lesions and the potential value of molecular testing should be considered in equivocal cases.

This case underscores the diagnostic complexity of pancreatic cystic lesions. It emphasizes the need for cautious interpretation of fine-needle biopsy findings and highlights the potential diagnostic bias introduced by fragmented care.