Platelet count and function studies are performed on a patient with a history of easy bruising,and the following results are obtained:
$\begin{array}{ll}
\underline { \text { Test }}&\underline { \text { Result }}\
\text { Platelet count } & 295 \times 10^{9} / \mathrm{L} \
\text { Platelet function assay } & \text { Prolonged } \
\text { Platelet aggregation with epinephrine } & \text { Primary but no secondary wave } \
\text { Platelet aggregation with low-dose adenosine } & \text { Primary but no secondary wave }\
\text { diphosphate (ADP) }\
\text { Platelet agoregation with ristocetin }& \text { Normal }\
\end{array}$
What is the most likely diagnosis for this patient?

Question

Platelet count and function studies are performed on a patient with a history of easy bruising,and the following results are obtained:
$\begin{array}{ll}
\underline { \text { Test  }}&\underline { \text {  Result }}\
\text { Platelet count } & 295 \times 10^{9} / \mathrm{L} \
\text { Platelet function assay } & \text { Prolonged } \
\text { Platelet aggregation with epinephrine } & \text { Primary but no secondary wave } \
\text { Platelet aggregation with low-dose adenosine } & \text { Primary but no secondary wave }\
\text { diphosphate (ADP) }\
\text { Platelet agoregation with ristocetin }& \text { Normal }\
\end{array}$
What is the most likely diagnosis for this patient?

Quizplus · Accepted Answer

The patient's test results indicate a normal platelet count but prolonged platelet function assay and abnormal platelet aggregation responses to epinephrine and ADP, with a primary but no secondary wave, which is characteristic of a dense granule deficiency. Normal aggregation with ristocetin helps differentiate it from other platelet disorders.

Platelet Count and Function Studies Are Performed on a Patient