Miliary brain metastases from occult lung adenocarcinoma: Radiologic and histopathologic confirmation

"Miliary brain metastases", also termed as "Carcinomatous encephalitis", are an extremely rare form of cerebral metastasis. Here in this article, we report a 52 year-old male patient with miliary brain metastases originating from occult lung adenocarcinoma. There were no significant findings on his initial physical and neurological examinations except limited cooperation. Brain computed tomography revealed edematous regions at the inferior sections of both parietal lobes. Then after, the contrast-enhanced magnetic resonance imaging revealed innumerable multi-dimensional lesions associated with surrounding edema on T2-weighted images. The proton magnetic resonance spectroscopy revealed increases in the choline and lipid peaks with decreased N-acetylaspartate in a similar manner with metastatic brain tumors. Histopathological findings pointed out that malignant epithelial tumor metastasis were originating in primary lung adenocarcinoma. Despite the advances in technical equipments and medical knowledge, miliary metastatic brain tumors are quite rare and the differential diagnosis is difficult. Our aim in this article was to present this rare case in which the lung was thought to be the primary focus; and outline the radiological characteristics. Also, we believe that the findings presented by proton magnetic resonance spectroscopy may contribute to making a differential diagnosis.