[Extreme reactive thrombocytosis in a healthy 6 year-old child]

Clinical course and short-term outcome of postsplenectomy reactive thrombocytosis in children without myeloproliferative disorders: A single institutional experience from a developing country

OBJECTIVES

To evaluate the clinical outcome and complications in the pediatric population who had splenectomy at our institution, emphasizing the incidence of postplenectomy reactive thrombocytosis (RT) and its clinical significance in children without underlying hematological malignancies.

MATERIALS AND METHODS

The medical records of pediatric patients undergoing splenectomy were retrospectively reviewed for the period 1999-2018. The following variables were analyzed: Demographic parameters (age, sex), indications for surgery, operative procedures, preoperative and postoperative platelet count (postplenectomy RT), the use of anticoagulant therapy, and postoperative complications. The patients were divided into two groups according to indications for splenectomy: The non-neoplastic hematology group and the non-hematology group (splenectomy for trauma or other spleen non-hematological pathology).

RESULTS

Fifty-two pediatric (37 male and 15 female) patients who underwent splenectomy at our institution were reviewed. Thirty-four patients (65%) were in the non-hematological group (splenic rupture, cysts, and abscess) and 18 patients (35%) in the non-neoplastic hematological group (hereditary spherocytosis and immune thrombocytopenia). The two groups did not differ significantly in regards to the patients' age, sex, and preoperative platelet count (P>0.05 for all variables). Forty-nine patients (94.2%) developed postplenectomy RT. The percentages of mild, moderate and extreme thrombocytosis were 48.9%, 30.7%, and 20.4%, respectively. The comparisons of RT patients between the non-neoplastic hematology and the non-hematology group revealed no significant differences in regards to the patients' age, sex, preoperative and postoperative platelet counts, preoperative and postoperative leukocyte counts, and the average length of hospital stay (P>0.05 for all variables). None of the patients from the cohort was affected by any thrombotic or hemorrhagic complications.

CONCLUSIONS

We confirm that RT is a very common event following splenectomy, but in this study it was not associated with clinically evident thrombotic or hemorrhagic complications in children undergoing splenectomy for trauma, structural lesions or non-neoplastic hematological disorders.

Platelets in Kawasaki disease: Is this only a numbers game or something beyond?

Kawasaki disease (KD) is a medium vessel vasculitis with predilection to cause coronary artery abnormalities. KD is now the most common cause of acquired heart disease in developed countries. Thrombocytosis is consistently found in patients with KD, usually in 2nd to 3rd week of illness. Thrombocytopenia has occasionally been reported in the acute phase of KD. An increase or decrease in platelet number in patients with KD was initially considered to be a benign phenomenon. However, recent literature on platelet biology in KD has suggested that platelets are not only increasing but are rather activated. This phenomenon has been found to increase the risk of thrombosis in these patients. Similarly a fall in platelet counts during acute stage of KD has also been found to be associated with increased severity of disease. In this review, we update on the current best understanding about pathogenic role of platelets in patients with KD.

Extreme Thrombocytosis in a Child: Laboratory Approaches and Diagnostic Challenges

Thrombocytosis in children as well as in adult is defined as platelet count ≥ 450 × 10⁹/L, and it is usually a reactive feature to various medical disorders. However, extreme thrombocytosis (platelet count ≥ 1000 × 10⁹/L) is an uncommon finding among pediatric and adult patients, which may indicate more than a reactive phenomenon. We describe a case of a five-year-old boy who was admitted due to recurrent epistaxis. He had no history of allergic tendency or trauma. Physical examination was unremarkable except for shotty neck nodes. Laboratory results at presentation showed normal hemoglobin and total leukocyte count with eosinophilia (0.92 × 10⁹/L), and extreme thrombocytosis. Other relevant investigations including coagulation profile, serum ferritin, liver, and renal function tests were all within normal ranges. Stool samples for ova and cysts were negative. The peripheral blood smear and bone marrow aspirate confirmed thrombocytosis with increased megakaryocytic proliferation and no artefactual reasons for the high platelets such as red blood cell fragments. Different causes of thrombocytosis in childhood were investigated after considering the possible differential diagnoses for extreme thrombocytosis.