20th July 2023

A 55-year-old man presents with a 1-year history of intermittent diarrhoea and fevers along with unintentional weight loss of 2.5 stones

A 55-year-old man presents with a 1-year history of intermittent diarrhoea and fevers along with unintentional weight loss of 2.5 stones. He denies any melaena or per rectum (PR) bleeding but has noticed significant worsening of his bilateral knee osteoarthritis and has new joint pain affecting his shoulders, lower back, wrists and ankles. In light of his GI symptoms, he undergoes an upper GI endoscopy which shows pale yellow duodenal mucosa with dilated villi. Histology from duodenal biopsies shows foamy macrophages containing large numbers of periodic acid-Schiff (PAS)-positive particles in the cytoplasm.

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