Hypervascular pancreatic lesions presenting as gastrointestinal bleeding

A 63-year-old female presented to the emergency complaining about severe asthenia, melena and altered bowel habits over the last two months. Consecutive blood tests in the emergency room revealed anaemia and a drop in haemoglobin levels by 1 g/dL (7 g/dL). History of right nephrectomy 10 years prior.

On admission, a gastroscopy was performed. It showed an extrinsic compression of the papilla and continuous bleeding that could not be managed endoscopically. A subsequent urgent computed tomography (CT) was then performed for further evaluation of the cause of bleeding. Multiphase abdominopelvic CT revealed three well-defined pancreatic lesions, showing homogeneous hypervascular enhancement in the arterial phase (video 1) which became isodense when compared with the pancreatic parenchyma in the venous phase (video 2, Figure 1). The largest lesion, located in the pancreatic head, had a mass effect on the second part of the duodenum and was obstructing and abutting the papilla. Dilation of the main pancreatic duct and the extrahepatic and intrahepatic bile ducts was observed.

Mild soft-tissue density surrounding the celiac trunk was visible, but no clear lymphadenopathy was detected.

Right kidney was absent due to previous nephrectomy.

Pericardial effusion without enhancement was an ancillary finding.

Endoscopic ultrasound-guided fine-needle aspiration cytology revealed pancreatic metastasis from renal cell carcinoma (RCC).

Pancreatic metastasis accounts for only 2-5% of all pancreatic malignancies [1], usually affecting elderly patients. Most cases are asymptomatic, being incidentally detected on imaging controls [2]. Common clinical presentation includes abdominal pain, weight loss, gastrointestinal bleeding, anaemia, jaundice and diabetic ketoacidosis [3].

Renal cell carcinoma (RCC) is one of the most common primary tumours metastatic to the pancreas [4], although pancreatic metastases are very unusual. Metastasis usually appears years after treatment; in fact, many cases have been reported over 10 years after nephrectomy [5] [6].

Abdominal CT is widely used to diagnose pancreatic metastasis. Small metastasis usually manifests as single or multiple well-defined nodules with avid homogeneous enhancement in the arterial phase and iso- or hypo-enhancement compared with pancreatic parenchyma in delayed phases [7] [8]. They can be easily missed if only delayed phases are available [2]. Larger lesions may have irregular enhancement due to central necrosis [9]. Metastasis can also present as diffuse pancreatic enlargement [7]. Head and body lesions can be associated with obstructive mass effect, with pancreatic and bile duct dilation (double duct sign), as in this case, although it is a non-specific finding [2].

Our patient underwent emergency gastroscopy for suspected gastrointestinal bleeding, revealing duodenal bleeding from the papilla (Figure 2). Multiphase abdominal-CT ruled out intraabdominal active bleeding. However, three hypervascular pancreatic lesions were found which were suspected to be a multifocal neuroendocrine tumour. Based on the clinical history of nephrectomy for clear cell RCC 10 years prior, the possibility of pancreatic metastasis was raised, but as a less likely option.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed. Cytology was consistent with a metastatic clear cell RCC (Figure 3).

Patient underwent surgery (Whipple procedure). The resected specimen showed a neoplasm with a hemorrhagic surface protruding into the duodenal wall (Figure 4a). Microscopically, it was composed of a combination of eosinophilic and clear cells (Figure 4b, 4c),  consistent with metastatic clear cell RCC grade 3.

To date, both medical treatment and surgical resection have proved effective. However, pancreatic metastases are very uncommon, therefore treatment stays controversial and must be individualized [10].

Prognosis varies for every patient, depending on primary tumour characteristics, number of metastasis and tumoural spread.

Metastasis from RCC should be included in the differential diagnosis of multiple hypervascular pancreatic lesions. Development of these metastases usually occurs many years after the initial RCC treatment.