Management of isolated leptomeningeal metastasis as the initial and sole site of recurrence in a patient with early-stage breast cancer

In breast cancer, leptomeningeal metastasis is increasingly seen in patients with hormone receptor and HER-2-positive disease as the newer therapies used have limited CNS penetration. Leptomeningeal disease is an end-stage presentation usually occurring in tandem with systemic metastases, limiting a patient’s overall survival to 6 months. We present a case with isolated leptomeningeal metastasis as the initial and sole site of recurrence in a patient with early-stage, luminal-type breast cancer. Despite the early stage at diagnosis, this patient recurred within three years likely due to high nodal burden at initial presentation. In the setting of leptomeningeal metastases without intraparenchymal or extracranial disease and good performance status, a patient’s overall survival can be extended longer than the average time span with the use of multiple intrathecal and systemic chemotherapies.