A peripheral blood smear shows light blue inclusions in the cytoplasm of neutrophils, and large platelets. Which of the following is the most likely diagnosis?

  • Incorrect. Alder-Reilly anomaly is associated with mucopolysaccharidosis (AR). WBCs show dense azurophilic granules resembling toxic granulation. Lymphocytes show metachromatic granules surrounded by a clear zone.

  • Incorrect. Chediak-Higashi syndrome is an autosomal recessive disorder caused by mutation of the lysosomal trafficking regulator protein. Phagolysosomes and melanosomes are dysfunctional, resulting in pyogenic infections, oculocutaneous albinism and peripheral neuropathy. Dohle bodies may be found in PMNS, and bone marrow biopsy shows inclusions in leukocyte precursors.

  • Correct. May-Hegglin anomaly is an autosomal dominant disorder characterized by thrombocytopenia, giant platelets with few granules, and light blue inclusions peripherally located in the cytoplasm of granulocytes. The mutation is in the gene encoding non-muscle myosin heavy chain IIA (MYH9).

  • Incorrect. Pelger-Huet anomaly is caused by mutations in a nuclear lamina (membrane) - specifically the lamin B receptor. It is autosomal dominant and characterized by hyposegmented neutrophils.

  • Incorrect. Pseudo Pelger-Huet anomaly, like Pelger-Huet anomaly, is characterized by hyposegmented, bilobed neutrophils. Pelger-Huet anomaly is genetic, pseudo Pelger-Huet anomaly is acquired, and can be an early sign of myelodysplasia. It can also be found in AML and CML, be drug induced, or from nutritional deficiencies (B12, folate) or infections.