Copper deficiency (hypocupremia) and pancytopenia late after gastric bypass surgery

Hypocupremia, or copper deficiency, is a rare and underrecognized cause of bone marrow dysplasia. Most cases of copper deficiency in adults occurred historically in patients receiving total parenteral hyperalimentation or total parental nutrition. More recently, with the obesity epidemic and the prevalence of gastric bypass, cases of malabsorption-related copper deficiency have occurred. Copper deficiency can lead to significant cytopenias and possible neurologic sequelae, which can be misdiagnosed and mismanaged. Unfortunately, a delay in diagnosis and appropriate treatment may lead to permanent neurologic damage. We describe a woman with previous gastric bypass surgery who presented with pancytopenia and bone marrow biopsy findings consistent with a myelodysplastic syndrome with excess blasts. She was found to be significantly copper deficient. With replacement copper therapy, her cytopenias quickly resolved. We discuss the distinctive clinical and hematologic features of this rare cause of significant cytopenias and provide recommendations for monitoring and treatment of such patients. Moreover, this case is an important reminder that bariatric patients should have routine follow-ups after surgery and continue dietary supplements indefinitely.