1989 A Rare Case of Renal Call Carcinoma With Metastasis to the Rectum and Gastric Body

Abstract

INTRODUCTION: Renal Cell Carcinoma (RCC) frequently metastasizes to the lungs, lymph nodes, bones, and liver via lymphatic, hematogenous, or direct invasion. Gastrointestinal metastasis is rare. We present a case of metastatic RCC to the gastric body and rectum presenting as melena and shortness of breath. CASE DESCRIPTION/METHODS: Patient is a 68-year-old male with a history of stage IV RCC to the skin and lung status post right total nephrectomy and right upper lobe wedge resection, who presented to the hospital with a one-month history of shortness of breath and 10–15 episodes of melena per day. On presentation, his heart rate was 121 bpm and blood pressure quickly dropped from 131/81 mmHg to 110/61 mmHg. Physical exam demonstrated abdominal tenderness and cachexia. Labs demonstrated hemoglobin 6.7 g/dL, which was 4 points lower than baseline and hyponatremia of 128 mmol/L. Other labs including hepatic panel and coagulation parameters were within normal limits. Hemoccult testing was positive. The patient was started on intravenous fluids, pantoprazole infusion, and blood transfusion (2 units). CT scan of the abdomen demonstrated a metastatic lesion in the sigmoid colon suggestive of an invasive metastatic lesion. Endoscopy revealed a nodule in the duodenum and mass was visualized on the greater curvature of the gastric body. Colonoscopy revealed a single polyp in the rectum, 10 mm in size. These lesions were biopsied and treated with bipolar cauterization. Pathological reports demonstrated metastatic carcinoma consistent with a renal primary source. DISCUSSION: RCC involves malignant cell proliferation in the proximal convoluted tubules of the kidney. Post-nephrectomy, there is still an approximate 20–40% chance of distal metastasis or locally recurrent disease. Thus, strict follow up is vital. While primary colorectal cancer is common, metastasis to this site is rare. There have been approximately 10 cases reported of metastasis of RCC to the rectum. Only 0.2–0.7% of RCC cases have been found to have metastasized to the stomach. This is the first case reported of synchronous metastasis of RCC to the rectum and gastric body presenting as melena as opposed to hematochezia. Although rare, clinicians should be mindful of this scenario and this case provides a clinical reminder.