BACKGROUND: Intrapancreatic accessory spleen (IPAS) can pose a challenge in the diagnostic workup by mimicking a pancreatic neoplasm. Reports of IPAS identified by endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) are scant in the literature, and increased recognition of this benign entity may reduce misdiagnosis and unnecessary surgical intervention. Here we report 2 cases of IPAS diagnosed by EUS-guided FNA biopsy. CASES: Each patient underwent computed tomographic evaluation for abdominal pain; it revealed a mass or thickening within the tail of the pancreas. Both patients were referred for EUS-guided FNA to further characterize their pancreatic lesions. In both cases, the cytomorphologic appearance of smears and cell blocks demonstrated aggregates of benign splenic tissue characteristic of both white and red pulp. Rare fragments of pancreatic acinar tissue were also identified. One cell block demonstrated benign splenic and pancreatic parenchyma immediately adjacent to one another without an apparent intervening capsule. CONCLUSION: IPAS can be diagnosed by FNA biopsy. Definitive tissue diagnosis in these 2 cases avoided not only unnecessary surgical intervention but also the need for consideration of a "watch and wait" strategy with further imaging and possible additional biopsy attempts.
BACKGROUND: Intrapancreatic accessory spleen (IPAS) can pose a challenge in the diagnostic workup by mimicking a pancreatic neoplasm. Reports of IPAS identified by endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) are scant in the literature, and increased recognition of this benign entity may reduce misdiagnosis and unnecessary surgical intervention. Here we report 2 cases of IPAS diagnosed by EUS-guided FNA biopsy. CASES: Each patient underwent computed tomographic evaluation for abdominal pain; it revealed a mass or thickening within the tail of the pancreas. Both patients were referred for EUS-guided FNA to further characterize their pancreatic lesions. In both cases, the cytomorphologic appearance of smears and cell blocks demonstrated aggregates of benign splenic tissue characteristic of both white and red pulp. Rare fragments of pancreatic acinar tissue were also identified. One cell block demonstrated benign splenic and pancreatic parenchyma immediately adjacent to one another without an apparent intervening capsule. CONCLUSION: IPAS can be diagnosed by FNA biopsy. Definitive tissue diagnosis in these 2 cases avoided not only unnecessary surgical intervention but also the need for consideration of a "watch and wait" strategy with further imaging and possible additional biopsy attempts.