PMON112 Primary Pituitary Lymphoma Presenting as Apoplexy

BACKGROUND: Primary pituitary lymphoma (PPL) in immunocompetent individuals represents a distinct and rare clinical entity. CLINICAL CASE: A 49-year-old menopausal woman with past medical history of hypertension and obesity who presented to the emergency room with sudden onset loss of vision in her right eye with blurriness on the left. She had been having intermittent headaches and flu-like symptoms over the 2 days preceding her presentation. Her BP was 179/116 mmHg, initial basic metabolic profile was normal, and head CT showed hemorrhage into a bilobed sellar and suprasellar mass measuring 2.2×2.2×3.3 cm. On ophthalmic exam, the right eye showed near-complete visual field loss with some residual island of vision superotemporally while left eye showed temporal hemianopsia. Initial endocrine workup was notable for a normal cortisol 15.9 (ref 2-20) ug/dL and normal prolactin; low-normal TSH 0.73 (ref 0.2-4.2) uIU/mL; low free T4 0.3 (ref 0.9-1.7) ng/dL; low FSH, LH, and IGF-1. She received a pituitary MRI showing hemorrhagic pituitary macroadenoma with significant upward bowing of the optic chiasm and infiltration into the cavernous sinuses. The patient developed diabetes insipidus (DI) before being taken to the operating room for transsphenoidal surgery with debulking and biopsy. Postoperatively and while waiting for pathology results, she developed panhypopituitarism and was being treated with hydrocortisone, levothyroxine, and desmopressin. Her pathology was consistent with diffuse large B-cell lymphoma (DLBCL) of non-germinal center type. She had a complete hematologic workup including whole body PET-CT showing sellar and suprasellar fluorodeoxyglucose avid disease without evidence of disease elsewhere in the head, neck, and torso which confirmed the diagnosis of PPL. The patient was started on chemotherapy using R-CHOP (rituximab, cyclophosphamide, hydroxyadriamycine, vincristine, and prednisone) with high-dose methotrexate. Following the first chemotherapy treatment cycle, she had a modest improvement in her vision; however, her DI was permanent. CONCLUSION: This case demonstrates that PPL can present with pituitary apoplexy and can result in panhypopituitarism and permanent DI. Individuals with this condition require a multidisciplinary care team including endocrinology, neurosurgery, hematology, and ophthalmology. REFERENCES: A Giustina, M Gola, M Doga, E A Rosei. Primary Lymphoma of the Pituitary: An Emerging Clinical Entity. JCEM. 2001 Oct;86(10): 4567-75.A Tarabay, G Cossu, M Berhouma, M Levivier, R T Daniel, M Messerer. Primary pituitary lymphoma: an update of the literature. J Neurooncol. 2016 Dec;130(3): 383-395. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.