Atypical Findings of Shwachman-Diamond Syndrome in Early Infancy: A Diagnostic Challenge.

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by hematological abnormalities, exocrine pancreatic insufficiency, and skeletal dysplasia. We describe a 2-month-old girl with intrauterine and extrauterine growth restriction who presented with an isolated severe anemia requiring red blood cell transfusion, without gastrointestinal symptoms, history of infection, or congenital abnormalities. An abdominal ultrasound revealed a reduced pancreatic thickness and abnormal echogenicity without fat infiltration, further confirmed by MRI. Because of this peculiar pancreatic appearance, pancreatic function was investigated and revealed exocrine insufficiency. Genetic testing confirmed SDS diagnosis. The typical clinical, laboratory, and imaging features of SDS are often lacking in the first months of life, and this may delay diagnosis. In early infancy, low birth weight and lack of catch-up growth, isolated hematological abnormalities other than neutropenia and atypical pancreatic imaging may lead to SDS diagnosis even when the most common diagnostic criteria are not fulfilled.