MON-109 Central Adrenal Insufficiency and Central Hypothyroidism in a Patient with Lymphoma

Abstract Disclosure: Z. Raad: None. L. Esper: None. N. Reyes: None. Background: Adrenal insufficiency due to metastatic disease most commonly is in the form of peripheral adrenal insufficiency (PAI), which is documented as an uncommon presentation of non-Hodgkin lymphoma (NHL).1 Here we discuss an even rarer case in which central adrenal insufficiency (CAI) resulted from suspected pituitary involvement of diffuse large B cell lymphoma (DLBCL).2Clinical case We consider the case of an 82 year old woman who was found to have DLBCL with central nervous system involvement due to presentation with adrenal insufficiency and central hypothyroidism. This patient presented with subacute progressive fatigue, exertional dyspnea, and deterioration of functional independence. She had tried and failed doxycycline for a presumed tick-borne illness as well as an additional antibiotic course for asymptomatic bacteriuria. Though she required a nasal cannula to maintain adequate oxygen saturation, apart from mild lower extremity edema her exam was benign. Initial workup was significant for severe hyponatremia (123 mmol/L, n 136-145 mmol/L) and marked central hypothyroidism with TSH 0.08 mIU/L (n 0.45-4.50 mIU/L), fT4 0.5 ng/dL (n 0.7-1.5 ng/dL), and fT3 1.4 pg/mL (n 1.6-3.9 pg/mL). Random cortisol obtained at 1 PM was 9.7 ug/dL, followed by an equivocal AM cortisol of 6.8 ug/dL. Due to concern for central hypothyroidism and CAI, brain MRI was obtained which showed asymmetric pituitary enlargement and other intracranial features concerning for neoplasm. Lumbar puncture showed mild leukocytic pleocytosis (9/uL, n 0-5/uL) without cerebrospinal fluid dyscrasia. Bone marrow biopsy revealed chronic lymphocytic leukemia (CLL), an unlikely culprit for her neuroradiology findings. Brain biopsy of the dura and frontal lobe revealed DLBCL likely resulting from CLL Richter transformation, elucidating the underlying cause of her CAI and central hypothyroidism. She was started on levothyroxine and hydrocortisone inpatient, which she was ultimately able to discontinue at outpatient follow up after starting dedicated treatment for DLBCL. Conclusion: This patient’s case represents an uncommon occurrence of NHL-induced CAI. Adrenal insufficiency without primary adrenal involvement in the setting of lymphoma warrants thorough investigation of central causes. References: 1) Rezkallah EMN, Hanna RS, Elsaify WM. Adrenal Lymphoma: Case Reports and Mini-review. Int J Endocrinol Metab. 2022 Aug 20;20(4):e128386. doi: 10.5812/ijem-128386. PMID: 36714190; PMCID: PMC9871959. 2) Tovar-Méndez VH, Cuenca D, Gómez-Pérez FJ, Cuevas-Ramos D. Pituitary Infiltration by Lymphoma. J Endocr Soc. 2022 Oct 27;6(12):bvac161. doi: 10.1210/jendso/bvac161. PMID: 36397777; PMCID: PMC9664974. Presentation: Monday, July 14, 2025