Localización atípica de linfoma primario de sistema nervioso central en región selar. Reporte de un caso y revisión de la literatura

Primary central nervous system lymphoma (PCNSL) -nonHodgkin- originates in the brain, eye, leptomeninges, or spinal cord without evidence of systemic lymphoma at the time of diagnosis. PCNSL is considered a rare malignant neoplasm, comprising 0.85% to 2% of all primary brain tumors, most commonly located in the periventricular region of the lateral ventricles; the majority are supratentorial in 50% to 70% of cases. The most common histopathological subtypes observed in the central nervous system are large B-cell lymphomas. For a definitive diagnosis, a biopsy is necessary to obtain histopathological and immunohistochemical confirmation, enabling the selection of specific treatment. Chemotherapy and radiotherapy are used as the primary treatments, with relapse occurring in 15% to 20% of cases within the first year and an overall 5-year survival rate from diagnosis, as neurosurgical treatment is often not feasible due to the lymphoma's location. A case is presented of a 55-year-old male patient who suddenly developed complete paralysis of the right third cranial nerve and peripheral vision disturbances. A diagnostic protocol was initiated, and due to brain MRI and clinical characteristics, the case was managed as a pituitary macroadenoma. The lesion was excised via an endoscopic transsphenoidal approach. Keywords: Lymphoma; central nervous system; sellar región; atypical; primary lymphoma.