Pancreatic metastases are rare (2-5% of pancreatic cancers) and the most frequent primary locations of tumor are lung cancer (40%) and gastrointestinal cancer (25%), among others. However, pancreatic metastases from renal cell carcinoma are very rare, accounting for only 1-2.8% of pancreatic metastases¹.

They usually present as metachronous metastases during the follow-up of patients who underwent surgery, even several years after surgery, and up to 50% are asymptomatic².

Surgery is the treatment of choice as the lesions do not respond to other treatments as chemotherapy.

We report the case of a patient treated with distal pancreatectomy and splenectomy through laparoscopy.

We report the case of a 61-year-old male patient with a history of right nephrectomy 10 years before consultation due to clear cell renal cell carcinoma. Nine years later, he underwent resection of metastases of the nasal cavity and parotid gland. An abdominal ultrasound performed during follow-up revealed the presence of a 27-mm solid nodule adjacent to the splenic hilum. A computed tomography (CT) scan showed a hypodense mass at the level of the tail of the pancreas with peripheral enhancement (Figure 1.A). The contrast-enhanced magnetic resonance imaging (MRI) evidenced intense enhancement in the arterial phase without thrombosis of the splenic vessels (Figure 1.B). A somatostatin receptor-targeted positron emission tomography (PET)-CT scan did not show higher uptake at the level of the tumor or abnormal expression of somatostatin receptors. The tumor markers (CEA, CA 19-9, 5HHIA) were within normal ranges.

The patient underwent laparoscopic left antegrade distal pancreatectomy and splenectomy with favorable postoperative outcome. The latter was performed to facilitate the technique. The patient was placed in reverse Trendelenburg position, the surgeon stood between the legs and the assistant on the sides of the patient. A 10-mm trocar was inserted above the umbilicus, a 5-mm trocar between the 10-mm trocar and the subxiphoid area and two 12-mm trocars in both hypochondriac regions. A left subcostal transverse mini-incision was performed to remove the surgical specimen and a drain was placed close to the pancreatic stump (Figure 2). Operative time was 150 minutes.

The surgical specimen contained a yellowish-brown nodular tumor measuring 25 × 25 × 20 mm (Figure 3). The microscopic examination showed a clear cell carcinoma with a compact and alveolar pattern with necrosis and hemorrhage, histological grade 2, scarce mitosis, and immunohistochemical staining pattern positive for PAX8 (Figure 4.A) and RCC (renal cell carcinoma) (Figure 4.B).

The patient was discharged on postoperative day 6 without complications. At the present time he has been operated on for three months, with no clinical signs of recurrence, waiting for the estimation of tumor markers.

Pancreatic metastases from clear cell renal carcinoma (which accounts for 80% of renal cancer during the 6th decade of life) are very rare. Although many autopsy series reported that the most frequent primary locations of tumors with pancreatic metastasis are lung and gastrointestinal tumors (42 and 24.7%, respectively), in surgical cases metastases of renal cell carcinoma are more common³.

Metastases occur by hematogenous or lymphatic spread, and tumor cells of renal cell carcinoma apparently have a high affinity for the parenchyma of the pancreas, which would explain pancreatic metastases and the absence of metastases to other organs. However, an additional feature of clear cell carcinoma is its ability to metastasize to any organ at any time. In fact, pancreatic metastases have been described up to 27 years after the primary tumor was resected⁴. In this case, the pancreatic metastases developed at long-term follow-up (metachronous disease), 10 years after the nephrectomy, while a year earlier metastasis had also been resected in distant sites (nasopharynx and parotid gland).

The clinical presentation is asymptomatic in up to 50% of the cases, as in our patient in whom pancreatic metastases were an incidental finding during follow-up with imaging tests, an expected situation in the case of a small tumor located in the tail of the pancreas.

Contrast-enhanced imaging tests (CT scan, MRI) show hypervascular lesions in the early arterial phase, as opposed to primary pancreatic tumors that are often hypovascular⁵. The role of PET/CT scan is not yet well defined, although in this case it was useful to exclude a neuroendocrine tumor. Finally, fine needle aspiration (FNA) is not usually indicated due to the risk of bleeding.

Resection should be attempted in patients with favorable clinical status and in the absence of metastatic extrapancreatic disease or unresectable primary tumors. Resection increases survival and improves quality of life, especially in those patients with disease-free survival > two years⁶. In fact, the history of resection of single or multiple metastases, even in distant sites as in the case analyzed, does not contraindicate pancreatic resection. This is due to the relatively high survival rates reported after resection (between 29 and 88%), as opposed to the poor prognosis of pancreatic metastases from carcinomas other than renal cell carcinoma. Radical resection is indicated with microscopically tumor-free margins. The immunohistochemical staining pattern is positive for CD10 and vimentin. In our case, the staining pattern positive was for PAX8 and RCC.

The importance of surgical treatment is based on the lack of response to chemotherapy, radiotherapy and hormone therapy, although phase III trials are investigating the efficacy of immunotherapy with agents such as sunitinib and bevacizumab.

Pancreatic metastases from clear cell renal carcinoma are very rare. However, surgical resection, if feasible, is associated with a high rate of success and should always be performed. In our case, a successful oncological resection could be perfaormed through a minimally invasive approach.