Pituitary lymphoma appearing 9 years after pituitary adenoma resection.

Background: Pituitary lymphomas (PLs) are very rare, accounting for <0.1% of all intracranial tumors. Of which, PL that is associated with PL is even rarer. Here, we describe a case of PL of a 51-year-old woman that appeared 9 years after pituitary adenoma resection. Case Description: A 51-year-old woman presented with visual disturbance. She had a history of pituitary adenoma resected through endoscopic trans-sphenoidal surgery (eTSS) 9 years before. Although her previous annual follow-up did not show any signs of recurrence, she noticed visual disturbance. One month later, her visual acuity rapidly worsened with headache and fatigue, being referred to our hospital. On examination, she had bilateral quadrantanopia. Her laboratory data showed slightly increased prolactin levels. Magnetic resonance images showed a mass in the sella with suprasellar extension, so she underwent eTSS. The tumor had a fibrous, hard part and a soft gray part, and it was mostly resected. Visual symptoms improved transiently, but ophthalmoplegia appeared 2 weeks after surgery, indicating intrathecal dissemination. Histological analysis confirmed the diagnosis of T-lymphoblastic lymphoma. Positron emission tomography showed tracer accumulation at the pancreas, confirmed as lymphoma through biopsy. However, we could not determine which site of lymphoma was the primary site. She underwent chemotherapy, including cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride, dexamethasone, and methotrexate. The patient died despite several months of treatment. Conclusion: Recurrence of pituitary adenoma cannot be carelessly assumed from a pituitary growing mass after pituitary adenoma resection. PLs have poor prognosis due to their aggressive character. Immediate biopsy and confirmation of the diagnosis are necessary for the treatment of pituitary masses with aggressive features.