Thrombocytosis in young people: Evaluation of 57 cases diagnosed before the age of 40

Abstract

Over the past 13 years 57 cases of primary thrombocytosis in young people have been studied. Only patients with a platelet count over 500 x 10(9)/liter and a follow-up longer than 2 years were considered. Thrombocytosis in young people represents approximately 25% of total cases referred to our department during this period. The most common causes are essential thrombocythemia (20 cases) and secondary thrombocytosis (22 cases). The highest platelet counts are found in essential thrombocythemia patients. Most of our patients were discovered by a fortuitous hematological examination. In contrast, 5 out of the polycythemic patients were recognized after a thrombosis. The same was true for 2 out of 20 essential thrombocythemia subjects. Four subjects (2 essential thrombocythemia and 2 secondary thrombocytosis) were diagnosed after hemorrhages. The overall survival was very good except for leukemic patients and thrombocytosis secondary to neoplasms. Vascular complications after diagnosis were scarce: 2 polycythemia vera patients showed bleedings during antiaggregating therapy. None of our patients developed epithelial cancer, malignant lymphoma or myelofibrosis. Vascular traumata seem more frequent in polycythemia vera regardless of age. Therefore, it seems useful to treat polycythemic patients, while no therapy seems to be indicated in other forms of thrombocytosis.

Should a platelet limit of 600 × 109/l be used as a diagnostic criterion in essential thrombocythaemia? An analysis of the natural course including early stages

“…The frequency of complications increased with older age. But serious complications and ET-related deaths were also observed in young patients of our study and of other reports (Millard et al, 1990;Mitus et al, 1990;Randi et al, 1990). This may be relevant for therapeutic decisions, despite the good overall prognosis.…”

Primary thrombocythemia: diagnosis, clinical manifestations and management

“…With the advent of automated platelet counting, PT is diagnosed with increasing fre- [25,31,40,43,48]. While it was initially suggested that PT might have a more benign course in younger patients [25], several studies since then [31,40,43,48] have demonstrated that PT in young patients may result in serious and life-threatening hemostatic complications. In general, the major causes of mortality and morbidity in PT are attributed to thrombohemorrhagic sequelae [6,13,14,16,21,24,27,47,49,59].…”

“…PT has usually been considered a disease of the middle aged, with its onset in the fifth to sixth decades of life and a slight female preponderance (Table 2) [6,13,14,16,21,24,27,[47][48][49]59]. With the advent of automated platelet counting, PT is diagnosed with increasing fre- [25,31,40,43,48].…”

Thrombocytosis in Childhood

“…Some authors 8,9 define thrombocythemia as a longlasting and very pronounced thrombocytosis (more than 1000 X 10 9 /L), others use the term "thrombocythemia"corresponding to the term leukemia-when thrombocytosis is caused by an autonomous defect of stem cells, for example in myeloproliferative disorders. 10,11 More practical is the classification of thrombocytoses according to their origin into primary and secondary forms. An increase in platelet count generally has one of three causes: (1) A primary disorder, such as a myeloproliferative or myelodysplastic syndrome, which is classified as primary thrombocytosis; (2) an increased production due to stimuli (a prolonged survival time of platelets as cause for thrombocytosis has not yet been described); or (3) a shift of platelets from the splenic pool into the peripheral circulation.…”