Massive Splenomegaly is least likely to be associated with which of the following Myeloproliferative disorders:

Answer is C (Essential Thrombocytosis (ET)) Essential Thrombocytosis is not associated with massive splenomegaly. 'Physical Examination in Essential Thrombocytosis is generally unremarkable except occassionally for mild splenomegaly. Massive splenomegaly is indicative of another Myeloproliferative disorder in paicular PV, PMF or CML --Harrison 1867/903 `Splenomegaly in Essential Thrombocytosis is seen in less than 30% of patients, and when palpable the spleen is usually not enlarged more than 4 cm below the left costal margin'.