PA H6 | Aplastic Anemia & Bone Marrow Failure — Practice Quiz

A 22-year-old male presents with fatigue, easy bruising, and recurrent oral ulcers for 3 months. Examination reveals pallor and petechiae but NO hepatosplenomegaly or lymphadenopathy. CBC shows Hb 6.2 g/dL, TLC 1.8 × 10⁹/L, Platelets 18 × 10⁹/L, Reticulocytes 0.2%. Bone marrow trephine biopsy shows <25% cellularity with fatty replacement. What is the MOST likely diagnosis?

Which of the following BEST defines aplastic anaemia?

A patient develops severe pancytopenia 6 weeks after starting chloramphenicol therapy for a typhoid relapse. Bone marrow trephine shows >75% fatty replacement. This presentation MOST likely represents which aetiological category of aplastic anaemia?

A 12-year-old boy is found to have aplastic anaemia. He also has short stature, café-au-lait spots, absent thumbs, and abnormal radii bilaterally. Chromosomal fragility testing (diepoxybutane test) is positive. What is the MOST likely diagnosis?

Which of the following BEST describes the central pathogenetic mechanism in most cases of acquired aplastic anaemia?

In a patient with aplastic anaemia, which combination of peripheral blood findings is MOST characteristic?

A haematologist performs a bone marrow aspiration in a patient with suspected aplastic anaemia but obtains no marrow particles — only blood. This result is called a 'dry tap'. What does a dry tap MOST commonly indicate in this context?

A bone marrow aspiration shows hypocellular fragments with predominant fat cells and marked reduction in all haematopoietic precursors. A trephine biopsy from the same patient shows 15% cellularity with the remainder being fat spaces. Based on WHO/ICSH criteria, this marrow cellularity is classified as:

A 19-year-old woman presents with pancytopenia (Hb 7.1 g/dL, WBC 2.0 × 10⁹/L, Platelets 22 × 10⁹/L). Bone marrow trephine biopsy shows 20% cellularity with dysplastic changes in the residual erythroid and myeloid precursors, including abnormal nuclear budding and hypolobated megakaryocytes. Cytogenetics shows del(5q). What is the MOST likely diagnosis?

CLINICAL VIGNETTE: A 16-year-old girl is brought to the ED with a week of progressive pallor, gum bleeding, and high-grade fever. She has no significant past medical history. Examination: pale, petechiae over both lower limbs, no hepatosplenomegaly, no lymphadenopathy. CBC: Hb 5.8 g/dL, WBC 1.4 × 10⁹/L (neutrophils 0.3 × 10⁹/L), Platelets 8 × 10⁹/L, Reticulocytes 0.1%. Peripheral blood film: normocytic RBCs, no blasts. Bone marrow trephine: <25% cellularity. Which ONE investigation result would MOST strongly suggest an immune-mediated mechanism (supporting the use of ATG + cyclosporin as treatment)?