Vol 16, No 2 (2017)

The standard immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine in treatment of acquired aplastic anemia (AA) results to hematologic response in two thirds of patients, and approximately one third of the responding patients is relapsed. One third of patients have disease that is refractory to IST, with persistent severe cytopenia and a profound deficit in hematopoietic stem cells. In patients with refractory or recurrent disease, the use of alternative immunosuppressive drugs is possible, but the efficacy of the latter does not high. Recent studies have demonstrated the efficacy of eltrombopag in refractory aplastic anemia and in the first line of therapy in combination with IST. It has been shown eltrombopag not only restored the level of platelets, but was associated with multilineage clinical responses. In this study we analyzed the use of eltrombopag in 15 children and young adults with AA: 11 patients in refractory disease, one patient in relapse and three patients in the first line of therapy in combination with IST. The overall efficacy of treatment was 40% (6/15). The main adverse event was moderate and reversible increase of hepatic transaminases (3/15, 20%). A complete hematologic response was achieved in 3/15 patients (20%), and in 2 patients the response is continued after drug withdrawal. Eltrombopag is effective in patients with refractory AA, and it may be an alternative option in patients who do not have suitable donors for hematopoietic stem cells transplantation (HSCT). The first-line treatment with eltrombopag in combination with standard IST in our small group of patients also showed efficacy (60%) and safety.

Aneurysmal bone cyst (ABC) is a destructive, expansive, benign neoplasm of the bone composed of multiloculated blood-filled cystic spaces. ABC is one of the common variant of primary bone lesion in children and adolescents. Using the reproducible clinical settings (age, location in the bone, pattern of bone alteration and type of periosteal reaction) it is not difficult to diagnose this neoplasm except its solid variant. Clinical and histological data were analyzed in order to improve the diagnostic and treatment of children and adolescents with ABC. From January 2009 to October 2016 there were 863 cases of bone tumors in children and adolescents. ABC was found in 58 cases (6,72%). In 13 cases, a pathological bone fracture was the first clinical sign. The correct clinical diagnosis of ABC before histological examination was made only in 22,41% cases. Microscopically, the classic (cystic) variant of ABC was observed in 50 patients, solid variant in 8 cases. The most difficult differential diagnosis of the aneurysmal bone cyst was with the teleangiectatic osteosarcoma, which has many clinical, radiological and histological similarities. ABC should be diagnosed and treated by a multidisciplinary approach by their clinical, radiological, and histological features.

Malignant fibrous histiocytoma (MFH) is a rare “NON-RMS-LIKE” pediatric tumor with highly malignant clinical behavior, high metastatic potential and overall 5-year survival around 65-70%. Soft tissue  sarcoma diagnostic work-up and optimal combination of systemic therapy and local therapy approaches are one of  the most challenging issues in modern pediatric oncology. To present a clinical case of parameningeal  undifferentiated pleomorphic sarcoma in 7-year old child treated with adaptive conformal radiotherapy  aimed at local tumor control. We describe a method of combined treatment of patient with parameningeal  UPS consisting of the intensity-modulated radiotherapy (IMRT) in the form of volumetrically-modulated arc- therapy (VMAT) aimed at local tumor control. The radiotherapy course was completed at the planned total  dose of 54 Gy. Acute skin and mucosal toxicity not more than Grade 2 (RTOG scale) was noted during the  treatment. A good partial response was recorded after chemoradiotherapy course had been finished.  Histological verification of UPS diagnosis is complicated as substantial amount of tumor tissue material is  required for immunohistochemical and cytogenetical studies. An aggressive surgical approach is a method  of choice for local control in parameningeal soft-tissue sarcomas. However the adaptive radiotherapy was  the only possible treatment method of local tumor control with significant decrease of high doses to adjacent normal organs and tissues.

Primary Myelofibrosis (PMF) is a rare chronic myeloproliferative disease, resulting from the transformation of cells-predecessors of myelopoiesis with the development of fibrosis bone marrow. PMF is typical for  patients over 50 years and in most cases associated with JAK2 V617F, CALR and MPL mutations. This article presents clinical case of PMF in 15-years old child and provides an overview of the literature.

The development of modern radiological technics has led to significant growth of both medical related radiation exposure levels and their share in overall radiation exposure. This article describes modern opinions on linear non-threshold model for radiation exposure stochastic effects and the latest tendencies in scientific discussions. The measurements for radiation exposure are crucial for pediatric oncology and thus require continuous research. Some publications are based on the current model, some state that this model is outdated and not proved enough. All data which we did put into this article was based on mix contingent research, we didn’t find any studies which were based specifically on children. Due to different opinions which are present currently, the strict control over diagnostic radiation dose is required for pediatric oncology patients. They should be equal or lower the 100 mSv dose level when clinically possible, otherwise additional efforts for dose saving are required in order to minimize the possibility of late radiation exposure effects from diagnostic radiological examinations.

Widespread introduction in the protocols of treatment of patients with tumors of a CNS of a chemotherapy allowed to improve the prognosis for many patients. At the same time, for a part of patients use of an chemotherapy does not give desirable effect, significantly increases treatment cost, and followed by toxic complications. On the example of use of a temozolomide in treatment of gliomas it is shown that its application allows to improve results of treatment only at a part of patients with the concrete positive clinico-biological and molecular characteristics. For the others patients medicine does not give positive results and significantly increases treatment cost. Experience of application of a temozolomid demonstrates that it is possible to personalize programs of treatment on the basis of already established prognostic factors. Their use will allow to refuse reference application of drugs according to only morphologic or only clinicoradiological diagnostics and to be guided by the individualized indications based on the clinico-biological parameters and molecular characteristics of this tumor. It will allow to reduce treatment cost at preservation of its effectiveness and decrease of toxic complications.