RESUMO
INTRODUCTION: Small-bowel myeloid sarcoma is rare. Acute bowel obstruction is its usual clinical presentation. PRESENTATION OF CASE: We report a case of small-bowel myeloid sarcoma that occurred in a 64-year-old woman who presented chronic secretory diarrhoea, hypokalaemia, and weight loss. Immature white blood cells in a peripheral smear and small-bowel capsule endoscopic features were the main diagnostic clues. The patient experienced capsule retention and developed acute bowel obstruction. Urgent laparotomy showed a stricturing ileal mass and pathology of the resected bowel specimen unveiled a CD34+, CD117+, and myeloperoxidase-positive myeloid sarcoma. The diarrhoea promptly resolved after surgery, and the patient is now undergoing chemotherapy. DISCUSSION: Secretory diarrhoea can be the first manifestation of small-bowel myeloid sarcoma. Capsule endoscopy may provide a diagnostic clue, but it can trigger an acute bowel obstruction. Differential diagnosis of the pathologic specimen may be difficult and a high suspicion index of is mandatory to perform immunophenotyping to determine the correct management. CONCLUSION: Chronic diarrhoea with alarm features can be the first manifestation of small-bowel myeloid sarcoma.