Pancreatic metastases from renal cell carcinoma mimicking insulinomas

was notable; despite this, no pathological levels of insulin Case report and C-peptide were detectable. We omitted preoperative CT-guided needle biopsy because Whipple’s triad and the A 60-year-old man presented with RCC of the left kidney and was treated successfully by a transperitoneal nephfindings on CT supported the diagnosis of an insulinoma, because surgery is the treatment of choice for any rectomy in 1989. The histopathological examination revealed a small (2 cm in the greatest dimension) well malignancy of exocrine and endocrine pancreatic tissue, diCerentiated, clear-cell type RCC with microscopic vein involvement. The tumour was resected radically; furthermore, no regional lymph nodes or distant metastases were found. Over a follow-up of 8 years there was no evidence of local recurrence or metastatic disease. The patient began to experience unpredictable episodes of hunger associated with sweating and dizziness in October 1997. During these episodes his blood glucose levels were decreased by up to 300 mg/L. Ultrasonography showed two hypoechoic lesions in the pancreas and subsequent CT of the abdomen showed two hypervascularized well-circumscribed tumours in the body (1.5 cm) and in the tail (2.3 cm) of the pancreas (Fig. 1). However, insulin and C-peptide levels were in the normal range. In January 1998 the patient was admitted to the Department of Surgery. A distal pancreatectomy with splenectomy, combined with a tumour enucleation, was performed after intraoperative ultrasonography. An accurate tumour classification from the intraoperative frozen section was not possible, but the surgical margins were free of tumour. The definitive histopathological specimens revealed two metastases of a clear-cell type RCC (Fig. 2); near these lesions some islet cells showed a moderate hyperplasia. The postoperative course was uneventful. During a 4-month follow-up the patient had no hypoglycaemic attacks and his blood glucose levels remained within the normal range.