Differential Diagnosis

The patient presents with moderate thrombocytopenia, large platelets, abnormal platelet adhesion, and a specific platelet aggregation tracing. Based on these findings, the differential diagnosis can be organized into the following categories:

• Single most likely diagnosis

  • D. Bernard-Soulier syndrome: This disorder is characterized by the absence of platelet glycoprotein (GP) Ib/IX/V, leading to impaired platelet adhesion to the von Willebrand factor. The presence of large platelets and moderate thrombocytopenia, along with abnormal platelet adhesion, strongly supports this diagnosis. The platelet aggregation tracing provided, where the control is the lower or blue line, also aligns with the expected findings in Bernard-Soulier syndrome, as these patients typically show a significant reduction or absence of the initial wave of platelet aggregation in response to agonists.

• Other Likely diagnoses

  • A. Von Willebrand Disease: While this condition primarily affects the von Willebrand factor and thus platelet adhesion, it does not typically result in the absence of GP Ib/IX/V or the presence of large platelets as seen in Bernard-Soulier syndrome. However, some types of von Willebrand disease could present with thrombocytopenia and might be considered in the differential due to the abnormal platelet adhesion.
  • B. Dense granule deficiency: This condition affects the dense granules within platelets, leading to impaired platelet aggregation. However, it does not typically result in the absence of GP Ib/IX/V or the characteristic large platelets seen in Bernard-Soulier syndrome.

• Do Not Miss diagnoses

  • C. Glanzmann’s thrombasthenia: Although Glanzmann’s thrombasthenia is characterized by a deficiency in GP IIb/IIIa, which is different from the GP Ib/IX/V deficiency in Bernard-Soulier syndrome, it is crucial not to miss this diagnosis due to its significant clinical implications. Patients with Glanzmann’s thrombasthenia have normal-sized platelets and a different pattern of platelet aggregation abnormalities compared to Bernard-Soulier syndrome.

• Rare diagnoses

  • Other rare platelet disorders could potentially present with similar findings, including certain types of platelet function disorders not listed here. These might involve defects in other platelet glycoproteins or signaling pathways, leading to variable presentations that could overlap with the described case. However, these would be less likely and would require specific diagnostic testing to confirm.