Gastroenterology clinical image challenge: An 86-year-old French man was admitted to the hospital with diarrhea, rectal bleeding and anal pain during defecation. He subsequently underwent digestive endoscopic examinations. The patient was a sturdy old man and a former soldier who had traveled overseas extensively, more than 30 years before presentation. He had been treated, two years prior, for adrenal insufficiency and myasthenia gravis with pyridostigmine, immunoglobulin infusions, and immunosuppressive drugs (azathioprine, later replaced by mycophenolate mofetil).
Clinical examination revealed two large perianal ulcerations (Figure A). Gastric fibroscopy was normal and colonoscopy showed a normal ileal mucosa and colorectal ulcerations with spacing of healthy mucous membrane. Biopsies of the colic and perianal ulcerations revealed a noncaseating epithelioid and giant cell granuloma, along with the presence of yeast, which led to a preliminary diagnosis of Crohn’s disease (Figure B, C; stain: hematoxylin eosin Safran staining; original magnification ×40 and ×100, respectively). Before the introduction of anti–tumor necrosis factor-α, laboratory results for tuberculosis, HIV, as well as hepatitis B and C were confirmed as negative. The patient was treated with infliximab but showed no improvement after three doses and he developed a fever. He was then treated with several probabilistic antibiotic therapies.
Laboratory results revealed a pancytopenia: white blood count, 2.2 × 109/L; hemoglobin, 9.1 g/dL; and platelets, 47 × 109/L.
What is the diagnosis?