Solid and cystic intrapancreatic accessory spleen: report of 10 cases in a single institution

Precise diagnosis of intrapancreatic accessory spleen (IPAS) remains challenging due to its rarity and diverse presentations. Despite comprehensive examinations, including radiography and other diagnostic methods, the potential for malignancy cannot be excluded, often leading to unnecessary pancreatic surgeries. We review our institutional experience to provide insights for accurately distinguishing IPAS.

We retrospectively reviewed 10 patients who underwent distal pancreatectomy for the lesion in the pancreas tail which was determined to be IPAS on final pathology at our institution between January 2020 and April 2024. The presenting symptoms, medical history, preoperative imaging, operative therapy, final pathology and postoperative course were evaluated.

Patient ages ranged from 30 to 72 (median 55.5), including six women and four men. Most patients were asymptomatic. One patient had the medical history of splenectomy. Lesions ranged from 1.4 to 7.3 cm (mean 2.9 cm). All lesions were located in the pancreatic tail. On radiologic evaluation, these lesions had both solid and cystic presentations. The most common operative approach was laparoscopic distal pancreatectomy and splenectomy. Four patients were diagnosed with epidermoid cysts arising in intrapancreatic accessory spleen (ECIPAS) on final pathologic evaluation.

IPAS are predominantly benign lesions which have solid and cystic presentations commonly mistaken for pancreatic neoplasms. Combining CT, MRI, EUS-FNA and nuclear medicine may enhance IPAS detection, though no definitive diagnostic method exists. Increased awareness of IPAS in the differential diagnosis of pancreatic tail tumors, coupled with advancements in imaging techniques could improve diagnostic accuracy and exclude malignancy, preventing unnecessary surgeries.