García, Francisco José ValdiviaCarrión, Natalia Palazónde la Cruz-Merino, Luis2023-02-082023-02-082020http://hdl.handle.net/10668/14910Leptomeningeal dissemination due to HER2-overexpressing breast cancer is a rare and hard to treat complication with short-term dismal prognosis. A 34-year-old female previously treated because of HER2+ breast cancer is admitted to the Neurology Department in December 2016 due to sensory-motor neurological semiology. A wide set of diagnostic tests is performed and finally cytologic findings after repeated CSF confirm leptomeningeal infiltration by breast carcinoma (panCK+, GATA3+). Weekly intrathecal triple therapy with methotrexate, cytarabine and hydrocortisone plus trastuzumab is carried out during 4 months. Clinical and pathological response that lasts more than 24 months. Leptomeningeal carcinomatosis is an oncological situation where conventional therapies have limited activity. In HER2+ advanced breast cancer patients, intrathecal therapy with anti-HER2 therapy (trastuzumab) is feasible and may reach long-term disease control, especially in cases of low-tumor burden.enAttribution-NonCommercial 4.0 Internationalhttp://creativecommons.org/licenses/by-nc/4.0/AdultAntineoplastic Agents, ImmunologicalBreast NeoplasmsCarcinoma, DuctalFemaleHumansMeningeal CarcinomatosisPregnancyPregnancy Complications, NeoplasticReceptor, ErbB-2Trastuzumabresearch article31895768open access10.1097/MD.00000000000182981536-5964PMC6946348https://doi.org/10.1097/md.0000000000018298https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946348/pdf