Introduction. The article analyzes the incidence of secondary malignant tumors (SMT) after therapy of Hodgkin’s lymphoma (HL) in 508 patients aged 0–18 years in the Republic of Belarus.

Materials and methods. Patients received program therapy under the DAL-HD-90(m) protocol. The observation period is from 10 months to 25 years. During the entire follow-up period, 27 secondary malignant tumors were diagnosed in 26 (4.1 %) patients: thyroid cancer – 11 (40.7 %), acute myeloid leukemia – 2 (7.4 %), stomach cancer – 2 (7.4 %), upper lobe bronchus cancer – 1 (3.7 %), parotid salivary gland carcinoma – 2 (7.4 %), breast cancer – 1 (3.7 %), hepatocellular liver cancer – 1 (3.7 %), soft tissue sarcoma – 2 (7.4 %), renal cell carcinoma – 1 (3.7 %), ovarian tumor – 1 (3.7 %), myelodysplastic syndrome – 1 (3.7 %), basal cell skin cancer – 2 (7.4 %). All cases of secondary hematological tumors were fatal.

Results. It was found that solid SMT developed within the area of radiation exposure to organs and tissues. The risk of developing SMT in patients with HL increases with increasing follow-up time after treatment. The cumulative incidence of SMT was 3.4 ± 0.8 % after 10 years, 4.6 ± 1.0 % after 15 years, and 7.0 ± 1.6 % 20 years after the diagnosis of HL. The latent period of SMT development after HL was 8.4 years (from 5 months to 23 years).

Conclusion. The data confirmed the need to optimize the therapy volume, reduce doses and indications for radiation therapy (RT), consider prognostic factors, introduce new RT methods, and use new treatment regimens for children with HL.

Background. Nowadays local modalities play an important role in retinoblastoma (Rb) treatment. Despite a great number of publications in scientific literature about local treatment there are no scientific works about comparative analysis of treatment results depending on tumor stage.

Purpose of the study – to evaluate the efficacy of local ophtalmological modalities of Rb treatment in different tumor stages.

Materials and methods. The study includes 274 patients (357 eyes) with Rb treated from 2007 to 2022. The mean patients’ age at the time of treatment was 15 months (from 0 to 74 months), 58 % patients were male, 42 % – female. 193 (70 %) patients presented with binocular Rb, 81 (30 %) – with monocular. In 59 (22 %) patients local treatment was performed on the single eye. Tumors’ distribution by stages was as followed: T1a stage (group А) – 74 (21 %) eyes, T1b (group В) – 122 (34 %) eyes, T2a (group C) – 56 (15 %) eyes, T2b (group D) – 104 (29 %) eyes, T3 (group E) – 3 (1 %) eyes. As local methods thermotherapy, cryotherapy and brachytherapy were applied. The follow-up varied from 6 to 158 months (median – 49 months).

Results. Local treatment modalitites were analyzed by following criteria: local tumor control, complications, eye salvage, number of applied treatment modalities, mean regression period and survival (overall and disease-free). Results were analyzed overall and by comparative analysis on different tumor stages. Local tumor control was achieved in 93 % of cases (n = 328), in 7 % (n = 26) tumor relapse was observed. Local treatment complications were observed in 23 % of cases (n = 82). 329 eyes (93 %) were salvaged, 25 eyes (7 %) were enucleated. All of these criteria were significantly lower in eyes of patients with Rb of group D (p < 0.01). Comparative analysis in different stages showed that tumor stage significantly affected local tumor control (p = 0.0012), complications’ frequency (р = 0.001), eye salvage percentage (р < 0.0001) and doesn’t affect regression period (p = 0.3), number of treatment modalities (p = 0.3), overall (p = 0.74) and disease-free survival (p = 0.3).

Conclusion. Local methods showed high efficacy in Rb treatment. Initial tumor stage is relevant in the prognosis of the treatment efficacy. Treatment of patients with Rb of group D still remains to be challenging in aspects of local tumor control and eye salvage.

Background. Nutritional support (NS) in children suffering from cancer and underweight is an important aspect of maintaining the growth and development of the child. The optimal method of short-term NS is endoscopically-assisted installation of a nasointestinal tube. Percutaneous endoscopic gastrostomy (PEG) is a minimally invasive surgical procedure for children who require long-term NS. Unlike the installation of a nasointestinal tube and the laparoscopic method of gastrostomy installation, PEG is characterized by a lower number of complications, ease and speed of installation and removal of gastrostomies, as well as better social adaptation of patients due to ease of care.

Purpose of the study – to present the experience of performing PEG and installing a nasointestinal tube for NS and the range of complications of PEG and tubes in children with cancer based on the experience of the N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia.

Materials and methods. In a retrospective study conducted at the N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia in the period from January to December 2022, the results of endoscopic diagnosis and treatment of 38 (100 %) children with cancer requiring long-term NS were analyzed. The first group included patients (n = 16; 40.1 %) requiring long-term NS (> 6 weeks), the second (n = 22; 59.9 %) – short-term NS (< 6 weeks). At the first stage, all patients underwent esophagogastroduodenoscopy to determine the possibility and method of performing PEG in the first group of patients and to install a nasogastric or nasojejunal tube in patients in the second group. At the second stage, patients from the first group underwent PEG using methods PULL and PUSH (in Russell modification).

Results. The first group of the study consisted of patients with cancer (n = 13; 34.2 %), aged from 4 months to 17 years (median age – 8.5 years), who underwent PEG PUSH (in Russell modification) (n = 8; 61.5 %) and PULL methods (n = 5; 38.5 %). In three patients, PEG was associated with a high risk of complications – obstruction of the gastric outlet with the intragastric part of the gastrostomy, perforation of the liver and colon, and therefore the patients underwent endoscopically-assisted installation of nasojejunal tubes. The main indications for PEG were: the need for long-term (> 6 weeks) NS (n = 13; 34.2 %) and the inability to feed independently (n = 13; 34.2 %). There was no correlation between the localization of the primary tumor focus and the PEG method (p > 0.05) (n = 13; 34.2 %). In 5.3 % of cases (n = 2), the installation of a gastrostomy tube was preceded by long-term (> 42 days) functioning of a nasointestinal tube. There were no developments of intra- and postoperative complications (median follow-up – 60 days) in the group of patients who underwent PEG (n = 13; 34.2 %). The second group of the study consisted of patients (n = 25; 65.8 %), in whom in 100 % of cases a nasointestinal tube was installed for NS for 7–30 days (average duration was 18.5 days), of which in 45. In 4 % of cases, complications such as migration of the probe into the lumen of the stomach (n = 4; 18.2 %), erosive and ulcerative changes with the formation of bedsores of the mucous membrane of the esophagus (n = 3; 13.6 %), stomach (n = 2; 9.1 %) and duodenum (n = 1; 4.5 %).

Conclusion. Enteral tube feeding is a safe and effective method of short-term NS for pediatric cancer patients, however, it may be associated with aesthetic discomfort, spontaneous removal of the tube, and a number of complications. PEG is the method of choice when long-term NS is required for patients under 18 years of age, characterized by minimal invasiveness and safety of the intervention, as well as ease of care, replacement and removal of gastrostomy tubes.

Introduction. Neuroblastoma (NB) is the most common extracranial solid tumor in children; it ranks third in the structure of childhood oncopathology, and in the structure of infant cancer up to 1 year of age, it ranks first. In children over 1 year of age, stages 3–4 are detected in more than 50 % of cases. In 60 % of cases, patients with stage 4 are diagnosed with bone marrow and/or bone involvement. This group of patients has one of the lowest survival rates in oncopediatrics. To carry out primary staging, assess the effectiveness of therapy, monitoring and for theranostic purposes, scintigraphy with 123I-MIBG is most often used. There are also studies demonstrating the diagnostic effectiveness of radionuclide studies of NB with somatostatin analogues, which include 99mTc-tectrotyde. Currently, two diagnostic radiopharmaceutical are registered in the Russian Federation: the “reference” 123I-MIBG, the most commonly used for diagnosing NB, and the potentially useful, but not used 99mTc-tectrotyde.

Purpose of the study – to determine the possibility of using 99mTc-tectrotyde as a diagnostic radiopharmaceutical for neurogenic tumors in children and compare the diagnostic capabilities of scintigraphy with 123I-MIBG and 99mTc-tectrotyde.

Materials and methods. The study included patients with a morphologically verified diagnosis before treatment: 7 patients diagnosed with NB and 1 with a diagnosis of paraganglioma. All patients underwent two consecutive scintigraphic studies: with 123I-MIBG and with 99mTc-tectrotyde with the minimum possible time interval between them (2–6 days), the sequence did not matter. A quantitative assessment of the accumulation levels of both radiopharmaceuticals was carried out using the SPECT/CT method.

Results. Compared with 123I-MIBG, 99mTc-tectrotyde scintigraphy allowed visualization of the primary tumor in 7 out of 8 patients, while all metastases were visible in only 1 out of 3 patients.

Conclusion. Our study was the first to compare 123I-MIBG and 99mTc-tectrotyde in the diagnosis of childhood neurogenic tumors before treatment. Scintigraphy with 99mTc-tectrotyde turned out to be applicable for the diagnosis of neurogenic tumors, however, a small sample of patients does not allow us to determine the diagnostic effectiveness and requires further study.

A retrospective analysis of histological studies of 60 enucleated eyes with a clinical diagnosis of the retinoblastoma (RB) was carried out. The article presents a summary data on changes in the retina, choroid, iris, sclera, optic nerve and other structures of the eye affected by the tumor, signs of the RB aggression, and ways of extrabulbar spread. A standardized protocol for morphological examination of the eyes with RB was used in the study. Attention was paid to the histological signs of therapeutic pathomorphosis of the RB, secondary glaucoma and subatrophy of the eyeball. The article also contains recommendations about macro- and microscopic examination of the eyeball with intraocular tumor – RB.

Hepatoblastoma is considered the most common malignant tumor with a stable tendency towards increased incidence in children. Prematurity is recognized as one of the significant risk factors associated with its development. Prematurity often coexists with a wide range of comorbid conditions, particularly in cases of deep prematurity stage IV. Such children are predisposed to a significant risk of intraventricular bleeding and chronic lung conditions, including bronchoalveolar dysplasia. The incidence of intraventricular bleeding is estimated to be between 20–40 %, while bronchoalveolar dysplasia ranges from 35–80 %. In cases of hepatoblastoma in premature children with these comorbid conditions, the surgical management stage (which typically includes chemotherapy) carries additional risks. There is limited data available regarding abdominal surgery in such patients, and notably, there have been no documented examples of extensive liver resections in this population. In this article, we will discuss two clinical cases detailing the surgical management of children with prematurity.

Lymphatic malformation of the bladder is a rare mesenchymal malformation that occurs in connection with dysembriogenesis of lymphatic vessels localized in the bladder. Depending on the histological picture, capillary, cavernous and cystic forms of lymphatic malformation are distinguished. This pathology occurs in any areas where there are lymphatic vessels. In clinical practice, lymphatic malformations in the neck and armpits are often encountered. The localization of this cystic formation in the bladder area is a rare find. Such patients seek help with characteristic clinical symptoms – dysuria, pain in the lower abdomen, macrohematuria, leukocyturia, which indicates hemorrhage in the formation or attachment of infection. Currently, pelvic ultrasound, cystography, CT of the abdominal cavity with contrast enhancement, cystoscopy, and laparoscopy are used for diagnosis. Given the benign nature of the formation, it is currently possible to remove it using minimally invasive video-assisted surgical techniques. This location of education has been described in the world literature 8 times since 1983. The publications are presented by 5 adult patients, 3 cases in children. In two patients, the formation was removed using robotic technologies and in one child – using laparoscopy. We have described a clinical case of this rare pathology in a 3-year-old child who sought hospital help with abdominal pain and was successfully treated using video-assisted surgical techniques.

Pseudoxanthoma elasticum (PXE) is a rare autosomal recessive disease, characterized by skin, retina and cardiovascular manifestations as a result of ectopic mineralization of elastic fibers of connective tissue. This is a case report of a 17-year-old patient with an isolated skin lesion and clinical and histological findings that are more typical of PXE. Due to the wide variability of phenotypic manifestations and the high risk of developing severe cardiac and ophthalmological complications, patients with suspected PXE diagnosis require careful follow-up even if genetic testing is negative and other diagnostic criteria are not fully met.