During the course of evaluation of a case of polycythemia following investigation may be required to establish the cause EXCEPT -
High-Yield Explanation
<p>In secondary polycythemia,erythropoietin levels are raised. Bone marrow examination shows erythroid hyperplasia . Aerial blood gas analysis to look for oxygen saturation .</p><p>Reference :Harsh mohan textbook of pathologysixth edition pg no 359.</p>