Persistent Altered Sensorium in a Patient Presenting With Acute Metabolic Encephalopathy From Diabetic Ketoacidosis and Metastatic Recurrent Melanoma of the Lung and Brain

Skin cancer, including melanoma, is a common type of cancer. Melanomas can develop anywhere on the skin and frequently metastasize to organs such as the brain, lungs, liver, and bones. We present the case of a 65-year-old male diagnosed with melanoma metastasis to his brain, causing expressive aphasia. This case is unique because the patient had undergone resection of stage IIC melanoma nine years prior. He initially presented with encephalopathy attributed to diabetic ketoacidosis, but persistent symptoms led to the discovery of brain metastases. He was ultimately diagnosed with metastatic melanoma and underwent whole-brain radiation and a trial of disease-modifying treatment with dabrafenib/trametinib. This case report aims to explore the disease progression of melanoma with metastasis to the brain and to highlight the importance of keeping brain metastasis high on the differential for encephalopathy in patients who have a history of melanoma, regardless of treatment resolution.