Splenunculi or accessory spleens are congenital foci of normal splenic tissue that are separate from the main body of the spleen. They are common, with a prevalence of 16% on contrast-enhanced abdominal CT, and present in 1030% of post mortem examinations. They are benign, and important to recognise to avoid unnecessary investigations and surgery for suspected malignancies.
Splenunculi are usually asymptomatic and found incidentally. Typically on CT they are well demarcated round lesions, <2 cm, and enhance homogeneously on contrast enhanced scans. Their radiological features are similar to the rest of the spleen. Location varies but the reporting of intrapancreatic accessory spleens is rare.
We present two cases of suspected neuroendocrine, pancreatic tumours. The first presented with a large, saddle shaped pulmonary embolus requiring thrombolysis, new onset diabetes and weight loss. CT and MRI pancreas revealed a solitary 14 mm lesion in the tail of the pancreas confirmed on endoscopic ultrasound. Fasting gut hormones and octreoscan were negative. Radiological surveillance showed no change over 12 months. Surgical resection was recommended following MDT discussion. Laparoscopic distal pancreatectomy was completed and histology confirmed a splenunculus.
Case two presented with small bowel obstruction requiring resection for carcinoid tumour. Postoperative CT scan showed solitary mesenteric node involvement. Octreoscan suggested a pancreatic lesion as well as the known mesenteric node. Follow up MRI showed progression of mesenteric disease but no suspicious lesion within the pancreas. Review of this scan and previous CT images show the lesion is most likely a splenunculus.
Advances in imaging techniques are expected to detect intrapancreatic splenunculi more frequently increasing the importance of being able to differentiate these lesions from more sinister pathologies.