From Toxic Ingestion to Cancer: Dramatic Acidosis as a Myeloma-Defining Event.

Acute kidney failure has myriad causes and presentations. This is a case of an individual with a history of alcohol abuse and a previous suicide attempt presenting with acute kidney failure and altered mentation accompanied by an anion gap metabolic acidosis with an elevated osmolar gap. These findings were concerning for toxic alcohol ingestion, but the patient was ultimately diagnosed with multiple myeloma. This case demonstrates the multiple factors that can impact both the anion and osmolar gaps. It shows that the traditionally held dogma about the meaning of anion or osmolar gaps may cloud an otherwise more obscure etiology. It illustrates a dramatic presentation of acute myeloma, for which early recognition is essential to initiate appropriate chemotherapy for a chance at preservation of renal function.