• Abstract Title • A Fatal case of Diffuse Large B Cell Lymphoma Presenting with Bilateral Necrotic Renal Masses. • Background • A 48-year-old woman with a history of chronic inflammatory demyelinating polyneuropathy presented to the hospital for failure to thrive. She experienced rapid decompensation during two consecutive hospitalizations; No diagnosis was able to be elucidated prior to patient expiring. • Case Presentation • A 48-year-old female with questionable past medical history of SLE and chronic inflammatory demyelinating polyneuropathy (CIDP), treated with weekly intravenous immunoglobulins (IVIG), presents to the hospital due to difficulty with activities of daily living, including eating and bathing. Family endorsed a thirty-pound weight loss with progressive dysphagia. CT Head showed right tentorium cerebellar lesion and CT abdomen and pelvis showed necrotic bilateral adrenal masses. Left retroperitoneal lymph node biopsy showed a benign reactive lymph node. Completed a Positron emission tomography (PET) scan depicting intensely avid bilateral adrenal masses with retroperitoneal and pelvic lymphadenopathy. • Three weeks after discharge, she presented back to hospital with worsening lethargy, microcytic anemia with hemoglobin of 6.9, hypotensive due to adrenal crisis responsive to fluids and stress dose steroids. New diffuse lower extremities purpuric lesions noted, for which biopsy showed leukocytoclastic vasculitis. Admitted to Medical Intensive Care Unit for worsening hyponatremia after fluid resuscitation and was started on 2% hypertonic saline. She was downgraded after resolution of hyponatremia and hypotension. She was again upgraded due to worsening fevers to 103F and started on broad spectrum antimicrobials: meropenem, vancomycin and fluconazole. Flow cytometry studies were negative. A large filling defect in the suprarenal inferior vena cava was noted and was started on apixaban. Despite all measures, the patient ultimately developed worsening hypoxic respiratory failure, was converted to comfort care measures and ultimately expired. • Pathology indicated Diffuse Large B-Cell Lymphoma returned after the patient expired. Initial differential diagnoses for this patient included lymphoma with negative biopsy due to steroid use as outpatient, Castleman disease, Rosai Dorfman disease or unspecified autoimmune disease. • Discussion • This case involves a young woman with controlled neurologic disease and multiple rheumatologic diagnoses. She presented with bilateral necrotic adrenal masses leading to adrenal insufficiency, which complicated her condition. Despite undergoing biopsy, no single diagnosis or syndrome was initially identified to explain the constellation of symptoms, and • unfortunately, the patient passed away from acute hypoxic respiratory failure. Diagnosis was limited by unusual symptom presentation and negative first biopsy.