MON-511 Large Bilateral Primary Adrenal Lymphoma: Anatomic and Functional Recovery of Primary Adrenal Insufficiency after R-CHOP

Abstract Disclosure: V. Master: None. E.K. Fishman: None. H. Li: None. A.H. Hamrahian: None. S.M. Chen Cardenas: None. Background: Primary adrenal lymphomas are exceedingly rare, with only a few hundred cases reported in the literature. Of those, about 38-70% are bilateral, and at least 60% result in primary adrenal insufficiency, which is usually permanent despite treatment response. Recovery has not been reported. Clinical Case: A 52-year-old woman with a history of type 2 diabetes and hypertension presented to the ER with abdominal pain, weakness, nausea, and vomiting that progressed over the previous 3 months. Abdominal CT revealed bilateral adrenal enlargement measuring 11.2cm in the greatest diameter on the right and 12.0cm on the left. Unenhanced CT density were 31 and 40 HU, absolute washout 0% and 49%. Labs: ACTH stimulation test: baseline cortisol 5.8 ug/dl, 30 min 5.8 ug/dl, 60 min 5.5 ug/dl, ACTH 310 pg/ml (6-50 pg/ml), PRA 8.59 ng/ml/hr (n, 0.25- 5.82 ng/ml/hr), Aldosterone <1.0 ng/dl, DHEA-S 7.0 ug/dl. She was started on hydrocortisone and fludrocortisone. On further interrogation, the patient reported night sweats, 40lb weight loss, which rose suspicion for lymphoma. LDH was 357 U/l (100-190 U/l). FDG PET/CT showed markedly avid bilateral adrenal masses as well as multiple subcentemeter retroperitoneal and mesenteric lymph nodes. A biopsy was performed that reported diffuse large B cell lymphoma, non-germinal center subtype. Immunostains demonstrated that the atypical lymphocytes express CD20, BCL6, and MUM1, and lack CD23 and CD10. Very focal expression of CD30. No follicular dendritic networks expressing CD23. The Ki67 proliferation index was 90-100%. FISH, was positive for rearrangement of BCL6 in 57% of nuclei. Negative for rearrangement of MYC and BCL2, no fusion of MYC and IGH or BCL2 and IGH. Patient completed 6 cycles of R-CHOP and prophylactic intrathecal methotrexate. Post-treatment FDG-PET/CT showed impressive reduction of the mass, with adrenals of a normal size and shape. The patient continued hormone replacement therapy. About 6 months after completing chemotherapy AM cortisol was 10.8 ug/dl, ACTH 198 pg/ml after holding her afternoon and morning dose of hydrocortisone. At 12 months the patient reported hypertension, hypokalemia, worsening hyperglycemia, lower extremity edema. Fludrocortisone was discontinued. Repeat AM cortisol was 14.ug/dl indicating the recovery of the adrenal glands. Her electrolyte abnormalities resolved, and blood pressure normalized. Conclusion: The recovery of adrenal function in the setting of primary adrenal insufficiency associated with bilateral lymphoma has not been previously reported. In patients with resolution of adrenal masses on imaging, recovery of adrenal glands should be assessed. Presentation: Monday, July 14, 2025