Renal cell carcinoma with atypical metastases sites revealed by diabetes mellitus: A case report

INTRODUCTION AND IMPORTANCE: Lung, bone, lymph nodes and liver are the most common metastatic sites. This observation presents a metastatic renal cell carcinoma (RCC) with atypical secondary sites and a rare mode of revelation corresponding to diabetes mellitus. CASE PRESENTATION: We report the case of a 64-year-old woman recently diagnosed with diabetes mellitus. A thoracic parietal nodule was palpated. An uro-CT scan had shown a renal tumor with unusual metastatic sites: pleura, pancreas, and contralateral kidney. The patient underwent a biopsy of the pleural nodule. The pathology report concluded to the diagnosis of clear cell RCC. She had a targeted therapy. Three months after admission, the patient had altered general condition and total hematuria. CLINICAL DISCUSSION: RCC commonly metastasizes haematogenously via renal veins. Atypically, secondary lesions may involve pleura. Such a metastatic site may be of particular interest for percutaneous biopsy, as in our case. The rare metastatic invasion of the pancreas is most likely the cause of the inaugural diabetes in our patient. The controlateral kidney was involved in 1.4% of secondary lesions. For patients with poor prognosis, according to International Metastatic RCC Database Consortium classification, anti-angiogenic treatment is recommended. The median overall survival of patients with poor prognosis is 8 months. CONCLUSIONS: Pancreas and contralateral kidney are rare secondary sites of RCC. The clinical expression of pancreas metastatic invasion can rarely fit with diabetes. Metastatic dissemination to these organs is most often associated with an unfavorable prognosis.