Spontaneous Resolution of Extreme Essential Thrombocytosis in a Child

Essential Thrombocytosis (ET) is rare in children and its clinical course is considered to be different from the adult disease. Unlike adults, most children with ET do not need treatment; however, children with extreme thrombocytosis present the treating physician with a therapeutic dilemma. We report a girl with a spontaneous resolution of extreme essential thrombocytosis. A 13 year old previously healthy girl presented to our ER with a 3 months history of intermittent mild abdominal pain with short episodes of diarrhea, intermittent episodes of paraesthesia in lower limbs and 3000 × 10 9 /L platelets on CBC with pseudohyperkalemia of 6.4 mEq/L. Physical examination was unremarkable except for some diffuse mild tenderness on abdominal palpation. Laboratory work-up revealed normal WBC and Hb, Platelets 4100 × 10 9 /L, mild microcytosis, Iron - 21.9 mcg/dL, transferin saturation 5.6%, serum potassium − 6.5 mEq/L, LDH 1000 IU. Liver, renal and thyroid function tests were within normal limits. PTT was mildly elevated 49.3 seconds (normal – 24.3–35), LAC-R mildly positive – 1.205 (0.8–1.20), KCT 58.2 sec. Anticardiolipin IgG −4.82 U/ml (negative), IgM - 11.24 U/ml (negative 9 /L. The spontaneous remission of the extreme ET achieved by conservative treatment with no complications adds to the growing evidence, that childhood ET is a unique entity with different biology than adult ET, which might not need antimetabolite therapy.