Congenital bone marrow failure syndromes and inherited cytopenias in pediatric oncology often present with characteristic combinations of hematologic laboratory abnormalities and physical exam findings. Match each of the following patient clinical vignettes with the most likely underlying syndromic diagnosis.
- A 4-month-old infant presents with progressive lethargy and pallor. Vitals are normal. Labs show Hb 4.2 g/dL, MCV 105 fL, reticulocytes 0.1%, and normal leukocyte and platelet counts. Exam reveals a webbed neck and triphalangeal thumbs.Diamond-Blackfan anemia
- An 8-year-old child presents with easy bruising and fatigue. Vitals: HR 110/min. Labs show Hb 7.1 g/dL, WBC 1,200/mm³, platelets 22,000/mm³. Exam reveals microcephaly, multiple café-au-lait macules, and absent thumbs bilaterally.Fanconi anemia
- A 2-year-old child presents with recurrent bacterial pneumonias and foul-smelling stools. Vitals: T 38.5°C. Labs show ANC 200/mm³ with normal Hb and platelets. Exam shows weight at the 5th percentile. Radiographs reveal metaphyseal dysostosis.Shwachman-Diamond syndrome
- A 12-year-old adolescent presents with worsening fatigue and recurrent epistaxis. Labs show progressive pancytopenia. Exam reveals dystrophic fingernails, lacy reticular pigmentation on the neck, and white patches on the buccal mucosa.Dyskeratosis congenita
- A newborn delivered at term presents with diffuse petechiae shortly after birth. Vitals are stable. Labs show platelets 12,000/mm³ with normal Hb and WBC. Exam reveals bilateral shortening of the forearms with absent radii, but thumbs are present.Thrombocytopenia-absent radius (TAR) syndrome
Answer
The correct matches align each clinical vignette with its classic syndromic diagnosis: The 4-month-old with isolated macrocytic anemia and triphalangeal thumbs has Diamond-Blackfan anemia; the 8-year-old with pancytopenia and absent thumbs has Fanconi anemia; the 2-year-old with neutropenia, steatorrhea, and metaphyseal dysostosis has Shwachman-Diamond syndrome; the 12-year-old with bone marrow failure and a mucocutaneous triad has Dyskeratosis congenita; and the newborn with thrombocytopenia and absent radii but preserved thumbs has Thrombocytopenia-absent radius (TAR) syndrome.
Each patient presentation contains classic, distinguishing features for a specific bone marrow failure syndrome. Diamond-Blackfan anemia is characterized by pure red cell aplasia and triphalangeal thumbs. Fanconi anemia features pancytopenia, absent thumbs, and café-au-lait macules. Shwachman-Diamond syndrome presents with neutropenia and exocrine pancreatic insufficiency. Dyskeratosis congenita is defined by marrow failure and a mucocutaneous triad. TAR syndrome is distinct for severe thrombocytopenia and absent radii with preserved thumbs.
Step-by-Step Solution
Key Concept
Differentiation of pediatric congenital bone marrow failure syndromes relies on identifying the specific affected cell line (e.g., RBCs vs. platelets vs. all lines) combined with highly characteristic physical anomalies (e.g., thumb presentation, mucocutaneous findings).