Abstract
Leptomeningeal metastasis (LMM), also referred to as leptomeningeal carcinomatosis, results from diffuse infiltration of the leptomeninges by malignant cells originating from extra-meningeal primary tumors. It occurs in approximately 5%-10% of patients with solid tumor. Among solid tumors, the most common types leading to infiltration of the leptomeninges are breast cancer, lung cancer, and melanoma. Patients with LMM may present various signs and symptoms. Herein, we report a rare case with initial presentation of isolated chest wall pain. Computed tomography of the chest with contrast revealed a 2.5-cm nodule over the left upper lung. Biopsy confirmed the diagnosis of adenocarcinoma. Later, cerebrospinal fluid cytology exam also confirmed leptomeningeal seeding. It is rare for leptomeningeal carcinomatosis patients to present with chest wall pain. Therefore, a high index of suspicion is mandatory for accurate and prompt diagnosis.