The Adrenals Under Silent Siege: Diffuse Large B-Cell Lymphoma Presenting as Addisonian Crisis.

Primary adrenal insufficiency (Addison's disease) is a potentially life-threatening disorder most commonly caused by autoimmune adrenalitis, though rare etiologies such as infiltrative malignancies must be considered, particularly when bilateral adrenal involvement leads to clinical manifestations. Diffuse large B-cell lymphoma (DLBCL), an aggressive subtype of non-Hodgkin lymphoma, may rarely involve the adrenal glands and precipitate adrenal crisis. We report a 58-year-old male patient who presented with giddiness, vomiting, fatigability, hyperpigmentation, weight loss, and hypotension. Laboratory evaluation revealed hyponatremia, bicytopenia, and markedly elevated adrenocorticotropic hormone (ACTH) levels, consistent with primary adrenal insufficiency. Imaging demonstrated bilateral adrenal masses with intra-abdominal lymphadenopathy, and histopathological examination of adrenal biopsy confirmed DLBCL. The patient was promptly treated with intravenous corticosteroids, resulting in hemodynamic stabilization while undergoing regular antidiabetic therapy. The patient was later referred to oncology for further management. This case highlights a rare presentation of DLBCL manifesting as Addisonian crisis due to bilateral adrenal infiltration. Given the nonspecific clinical features that often delay diagnosis, clinicians should maintain a high index of suspicion for malignant causes in patients presenting with adrenal insufficiency and bilateral adrenal masses, as early recognition and timely corticosteroid therapy are critical for improving outcomes.