Bloomy rind sign in meningeal metastasis of lung adenocarcinoma: A case report.

Lung cancer is one of the most common tumors linked to leptomeningeal metastasis. The diagnosis and assessment of this condition are based on cerebrospinal fluid analysis and magnetic resonance imaging (MRI), both with and without contrast. A newly identified imaging marker has emerged that directly indicates the presence of leptomeningeal metastases originating from lung adenocarcinoma. This marker, known as the "bloomy-rind sign," appears as hyperintensity on the FLAIR sequence of the brainstem surface without any abnormal enhancement. We report the case of a 46-year-old male patient who presented with severe symptoms, including dizziness, nausea, vomiting, hypoacusis, dysphagia, and dysarthria. The diagnosis of leptomeningeal metastasis was made upon observing the bloomy-rind sign, which ultimately led to the identification of lung adenocarcinoma. The underlying cause of the sign remains unclear, with proposed theories including tumor infiltration, microinfarction, or cytotoxic edema.