[Remarkable improvement of metastatic occipital condyle syndrome in a patient with lung adenocaricinoma treated with osimertinib].

A woman in her 50s. Since October of X-1, she had been suffering from lower back and occipital pain. Despite undergoing medical evaluations at multiple hospitals, no discernible abnormalities were identified. As her symptoms worsened, she presented to our department in January of X, reporting severe pain in the left occipital to posterior neck that increased with both neck flexion and extension. A neurological examination revealed a left-sided deviation of the tongue (left hypoglossal nerve paralysis). A head MRI revealed signal abnormalities in the left occipital condyle and multiple nodules with contrast effects in the brain parenchyma. A computed tomography (CT) scan revealed a mass in the left lung, multiple intrahepatic masses, and bone destruction in the spine and left occipital condyle. In light of these findings, a diagnosis of lung cancer with metastasis to multiple organs and occipital condyle syndrome due to metastasis to the left occipital condyle was suspected. Subsequent cytological analysis of bronchoalveolar lavage fluid and liver biopsy substantiated the diagnosis of adenocaricinoma. The subsequent administration of osimertinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, led to a reduction in the size of the tumor, as well as improvements in the hypoglossal nerve palsy and occipital pain. It is imperative to note that occipital condyle syndrome signifies the metastasis of a malignancy to the base of the skull, necessitating meticulous observation and management.