Presentation of extranodal NK/T-cell lymphoma as a pituitary mass: A case report and review of the literature

Background: Primary pituitary lymphomas are uncommon neoplasms that are typically derived from a B-cell lineage. Extranodal natural killer (NK)/T-cell lymphoma is distinct from B- and T-cell lymphomas and is associated with Epstein–Barr virus infection. Primary central nervous system (CNS) presentations of this neoplasm are exceptionally rare. Here, we report the case of extranodal NK/T-cell lymphoma presenting as a pituitary mass and review the literature related to this rare clinical entity. Case Description: A 31-year-old previously healthy male presented with 2 weeks of progressive headaches and ophthalmoplegia. Imaging revealed a large intrasellar mass with retroclival extension and involvement of the sphenoid and cavernous sinuses. An endoscopic biopsy of the sphenoidal mucosa was performed, and pathological examination was consistent with extranodal NK/T-cell lymphoma. Despite treatment with chemo- and radiotherapy, the patient died approximately 8 months after initial presentation due to systemic disease progression with multiorgan failure. Conclusion: The presentation of extranodal NK/T-cell lymphoma as a pituitary lesion is very rare, having been reported only twice in the previous literature. Patients with primary CNS extranodal NK/T-cell lymphoma typically experience an aggressive clinical course with a poor prognosis, as in our case.