Immune thrombocytopenia (ITP) is a disease with a heterogeneous clinical manifestation. In the majority of children newly diagnosed ITP is a self-limited benign disorder, while chronic ITP develops rarely. The clinical onset of ITP can occur in very different ways: from nearly invisible skin hemorrhage to severe life-threatening bleeding. Conventional treatments promote a response in most patients, but in a small number of children thrombocytopenia is unresponsive. In this article, we describe our experience of the clinical use of romiplostim in children with severe unresponsive newly diagnosed ITP. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. The severity of bleeding decreased significantly after the start of romiplostim therapy in all cases. Durable complete (platelets > 100 × 109 /l) response was achieved in five out of six patients 4 to 8 weeks after starting therapy. Three children have remained in lasting remission for 1 to 3 years after the discontinuation of romiplostim. There were no adverse events associated with romiplostim.

Infantile hemangioma (IH) is a benign vascular tumor with abnormal proliferation of endothelial cells and impaired vascular architecture. It is believed that the pathogenesis of IH is based on angiogenesis impairment caused by imbalance between angiogenic and anti-angiogenic factors. Despite spontaneous regression, which is observed in 90% of cases of IH, several tumor localizations may indicate the possibility of systemic manifestations or lead to the development of complications that require medical interventions. Here we report 2 cases of the most frequent and severe complications of IH and the first successful use of combined treatment strategy including metronomic chemotherapy (cyclophosphamide plus vinblastine) and nonselective b-blocker (propranolol) in IH. The parents of the patients agreed to use the information, including the photographs of children, in scientific research and publications. In contrast to glucocorticoids commonly used in clinical practice for complicated forms of IH, metronomic chemotherapy showed high efficacy and safety. It led to a rapid, within the first two weeks, clinical improvement resulting not only in stopping tumor growth, but even in size reduction. Such a rapid response to therapy allowed to stop the development of ulcers and necrosis with secondary infection, and to prevent severe vital complications of IH such as the upper respiratory tract compression.

Congenital hemangiomas are rare benign vascular tumors that develop in utero and are fully formed by the time of birth. Depending on the ability to involution, there are three subtypes: RICH (repidly involuting congenital hemangioma), NICH (non involuting congenital hemangioma), PICH (partially involuting congenital hemangioma). PICH may be accompanied by thrombocytopenia and consumption coagulopathy. Despite clearly defined clinical and histological characteristics, it can be difficult to make a differential diagnosis between congenital hemangiomas and other vascular tumors (infantile hemangioma, kaposiform hemangioendothelioma/“fascicular” angioma and others). The clinical case in the article of a vascular tumor in a newborn complicated by thrombocytopenia and consumption coagulopathy was regarded as Kazabach-Merritt syndrome, which is based on kaposiform hemangioendothelioma/“fascicular” angioma. Rapid regression of the tumor and recovery of hemogram and coagulogram parameters, as well as anamnesis of the disease and initial characteristics of the tumor forced to reconsider the diagnosis. Based on the histological picture, the diagnosis of congenital hemangioma, RICH, was confirmed. Verification of the diagnosis made it possible to change therapeutic tactics and avoid chemotherapy. A giant hemangioma, accompanied by thrombocytopenia and consumption coagulopathy, may have a very favorable outcome – a complete resolution of the pathological process inherent in its natural course. The patient's parents agreed to use the information, including the child's photo, in scientific research and publications.

Transient abnormal myelopoiesis (TAM) is a unique hematological syndrome specific for neonates with Down syndrome. Clinical and hematological manifestations of ТАМ are similar manifestations of acute leukemia, but they may resolve spontaneously by few weeks/months after birth. Summation trisomy 21 and GATA1 mutation in blast clone is a required element for development TAM. Presentation of this syndrome occurs in the first days of life; clinical manifestations may be absent (“silent” TAM) or even lead to death of fetus and neonate. The main interest in the study of this issue is the fact that after spontaneous regression there in 20% of cases at the age of 3–4 years developing acute megakaryoblastic leukaemia (AMKL). The basic transformation factors TAM to AMKL are unknown. In this article we represent 6 cases of TAM identified in Dmitry Rogachev National Research Center for Pediatric Hematology, Oncology, and Immunology from 2012 to 2019. Parents of these patients gave their agreement to use personal data in research and publications.