Calvarium Penetration from Intracranial Metastasis of Pulmonary Small Cell Carcinoma

While the incidence of lung cancer has been steadily decreasing in the United States, lung cancer remains the most lethal cancer with higher mortality than other types of cancer. Small cell lung carcinoma (SCLC) comprises approximately 10-15% of diagnosed lung cancers. It is characterized by its rapid growth and metastatic nature, with a majority of diagnoses of SCLC occurring after metastasis. Its propensity to spread quickly often necessitates initial systemic therapy. There are various metastatic sites of SCLC with metastasis to the brain among one of the most widely documented in literature. Brain metastasis in patients often occurs through hematogenous spread and represents poor prognosis, with an average survival of four to seven months despite whole brain radiation therapy - which is the current recommended treatment. Approximately 80% of brain metastases are documented in the cerebrum with only a minority demonstrating infiltrative growth pattern. In this case, we present a patient diagnosed with pulmonary small cell lung carcinoma with metastasis to the brain that penetrated through the bony calvarium. After an extensive literature search, the extension of brain metastasis through the skull - originating from a primary lung cancer - has only been identified in two other cases with this being the first documented case of SCLC.