Thymic carcinoma presenting with overlap polyarthritis and myositis: A rare paraneoplastic syndrome in childhood.

Thymic tumors are very rare neoplasms in children and account for less than 1% of mediastinal tumors in pediatric patients. One-third of the pediatric patients present with symptoms related to the compression of the tumor mass on the surrounding anatomic structures, and paraneoplastic syndromes such as myasthenia gravis, pure red cell aplasia, acquired hypogammaglobulinemia, and connective tissue disorders, which rarely occur in children with thymic tumors. Herein, we report a case of thymic carcinoma mimicking the symptoms of a connective tissue disease with symmetrical polyarthritis accompanying myositis, fever, weight loss, and malaise in a 15-year-old male patient. To our knowledge, this is the first case pediatric thymic carcinoma accompany with severe polyarthritis and myopathy, thus we have reviewed the current literature regarding the cases of thymic malignancies coexisting with paraneoplastic syndromes in children.

Immunohistochemical Approach to Mismatch Repair Deficiency in Pediatric High-Grade Glioma.

Knowledge of the molecular pathways of pediatric high-grade gliomas is increasing. Gliomas with mismatch repair deficiency do not currently comprise a distinct group, but data on this topic have been accumulating in recent publications. Immunohistochemistry can effectively determine mismatch repair status, indirectly suggesting the microsatellite instability of the tumor. This study aimed to determine the number of mismatch repair-deficient pediatric high-grade gliomas in a tertiary institution and assess the relationship between the survival and mismatch repair status of the patients. It also aimed to assess the potential for further clinical studies including immunotherapy. Of 24 patients with high-grade gliomas, 3 deceased patients were mismatch repair-deficient. Mismatch repair deficiency was significantly associated with shorter survival (P=0.004). Immunotherapy trials need to progress, and patients with mismatch repair-deficient pediatric high-grade gliomas are the most suitable candidates for such studies.

Retrospective Analysis of Paediatric Glial Tumours that Required Modern Molecular Techniques.

AIM: To determine if previous histological grading systems were sufficient or unreliable with a limited repository of modern techniques. MATERIAL AND METHODS: The pathology reports of pediatric neurosurgery patients between 2019-2022 were accessed. Data on patients that needed unattainable further molecular investigation were extracted. Data were noted from electronic archives, including their sex, age, histologic grade, location, resection type, survival, and therapy. RESULTS: Out of 61 surgeries, 17 patients needed further investigation for a proper 2022 World Health Organization (WHO) diagnosis. Seven were deceased, and nine were alive. Two of 10 patients with low-grade gliomas and five of six patients with highgrade gliomas were deceased. Data on one foreign patient with high-grade glioma was inaccessible. The average survival was 9 months for the deceased. CONCLUSION: Modern molecular techniques such as next-generation sequencing and methylation profiling are the state-ofthe- art methods, but it is hard for developing and underdeveloped countries to utilize such methods. The classification schemes, diagnostic key figures, and treatment modalities are developed using these techniques, but the less developed world is incapable of achieving these. We are trying to hybridize the modern and classic modalities, and the results of our study show that for overall survival, there is still not much difference. More economic and feasible techniques should be produced and summarized for the rest of the world.

Prognostic value of fluorodeoxyglucose positron emission tomography derived metabolic parameters and textural features in pediatric sarcoma.

PURPOSE: The aim of this study was to evaluate the prognostic value of PET-derived metabolic features and textural parameters of primary tumors in pediatric sarcoma patients. METHODS: The imaging findings of 43 patients (14 girls and 29 boys; age 11.4 ± 4.4 years) who underwent 18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography for primary staging prior to therapy between 2005 and 2020 were retrospectively evaluated. The diagnoses were osteosarcoma in 10, rhabdomyosarcoma in 10, and Ewing sarcoma in 23 patients. PET metabolic data and textural features of primary tumors were obtained. Cox proportional hazards regression models were used to identify predictors for progression-free survival and overall survival. Survival curves were estimated by using the Kaplan-Meier method. RESULTS: Distant metastases were detected in primary staging in 13 patients (30.2%). The median follow-up duration after diagnosis was 28 months (range: 10-171 months). In multivariate Cox regression analysis, the presence of distant metastasis and neighborhood grey-level difference matrix_Contrast (ngldm_Contrast) were found as independent predictors for both progression-free survival and overall survival. Grey-level zone length matrix_Zone-length nonuniformity (glzlm_ZLNU) was also found as an independent predictor for overall survival. The Kaplan-Meier survival analysis showed that higher ngldm_Contrast and glzlm_ZLNU values of primary tumors were significantly associated with shorter progression-free survival and overall survival. CONCLUSION: In addition to the presence of distant metastasis at initial diagnosis, textural features of primary tumors may be used as prognostic biomarkers to identify patients with worse prognosis in pediatric sarcoma. Higher tumor heterogeneity is significantly associated with shorter progression-free survival and OS.

Assessment of PD-L1 expression in patients with neuroblastoma and renal tumors.

BACKGROUND: Programmed death 1 (PD-1) is a co-receptor which is located at the surface of cells like natural killer, monocytes, T and B cells. It has two ligands including programmed death ligand-1 (PD-L1) and ligand-2 (PD-L2). T cell functions are inhibited by activation of PD-1/PD-L1 pathway and this pathway is used by viruses and some tumor cells in order to escape from immune eradication. In our study we evaluated PD-L1 expression in the tissue specimens of patients with Wilms tumor, neuroblastoma and other renal tumors. METHODS: Totally 60 patients who were followed up at Gazi University Hospital with the diagnosis of neuroblastoma, Wilms tumor and other renal tumors were included. PD-L1 expression was examined in tumor samples of the patients. RESULTS: Positive staining with PD-L1 was detected only in two male patients. Both of them had neuroblastoma and advanced stage disease. None of the patients with Wilms tumor and other renal tumors had positive PD-L1 staining. CONCLUSIONS: Unlike adult tumors, PD-L1 expression is not common in childhood tumors due to differences in immune system between children and adults. Further studies are needed to establish the importance and effects of PD-1/PD-L1 pathway in pediatric tumors.

IgG4-related disease and ANCA positive vasculitis in childhood: a case-based review.

Autoimmune pancreatitis (AIP) type 1 is an IgG4-related disease (IgG4-RD), characterized by inflammatory pseudotumors and histologically by dense lymphoplasmacytic infiltrates rich in IgG4 positive plasma cells, storiform fibrosis, and obliterative phlebitis. Although quite rare, IgG4-RD was found to be associated with medium or small vessel vasculitides. A new overlap syndrome between IgG4-RD and ANCA-associated vasculitis (AAV) has recently been described in the adult population. Here we present a 16-year-old adolescent girl admitted with abdominal pain, episcleritis, palpable purpura, salivary gland enlargement, and bloody diarrhea. Laboratory investigations revealed findings of glomerulonephritis. Abdominal imaging surprisingly revealed a focal mass in the pancreatic tail, while the c-ANCA level was found to be quite high as well as serum IgG4 level. Biopsy of the pancreatic mass showed lymphoplasmacytic IgG4 positive cells infiltrating the pancreas with storiform fibrosis compatible with IgG4-related AIP. The renal biopsy that was done simultaneously showed necrotizing granulomatous vasculitis indicating AAV. Renal biopsy showed IgG4 positive plasma cells very rarely by immunohistochemical examination, which does not indicate any significance for IgG4-RD. Our diagnosis was IgG4-related AIP and AAV overlap syndrome, which has not been reported in the pediatric populations yet. IgG4-RD should be investigated in patients with ANCA-associated vasculitis who shows atypical organ involvement. We searched the Pubmed/Medline and Google Scholar databases to identify clinical findings, treatment, and outcome of the patients with IgG4-related AIP and AAV.

Protective effects of hydrogen rich saline solution on ventral penile mathieu type flap with penile tourniquet application in rats.

INTRODUCTION: Penile tourniquet (Pt) application aims to work in a bloodless field in penile surgery. When the tourniquet is released, reperfusion injury occurs with the resumption of blood flow. Molecular hydrogen can easily attach to biomembranes and enter cytosol, mitochondria and other organelles of the cell and convert the formed OH- to H2O to prevent cell and tissue damage. AIM: We investigated the effects of hydrogen rich saline solution (HRSS) on penile Mathieu type flap tissue with Pt application in rats. STUDY DESIGN: Thirty-six Wistar-albino male rats were randomly divided into six groups. No operations were performed in the Sham group. Ventral penile Mathieu type flap was prepared and Pt was applied to the root of the penis with a plastic band in other groups. Pt was applied 10 and 30 min in the PT1° and PT³° groups. HRSS was injected intraperitoneally (ip) 5 ml/kg just before Pt was released in the HRSS1° and HRSS³° groups. In the HRSSB group, HRSS was injected 1 h before 10 min of Pt application. At the 4th hour of experiments the rats were sacrificed and tissue samples were taken for biochemical and histopathological studies. Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), myeloperoxidase (MPO), malondialdehyde (MDA) and glutathione (GSH) levels were determined in the penile tissue. The results were analyzed with one-way ANOVA and Pearson's Chi-Squared test. RESULTS: Tissue MDA, MPO, IL-6 and TNF-α values were significantly lower in all HRSS groups compared to PT1° and PT³° groups. Tissue GSH levels of HRSS groups were higher compared to PT groups. Histopathologically, inflammation was found to be higher in PT groups compared to HRSS groups. Interestingly, in the HRSSB group with HRSS administration prior to Pt, the damage was less in grade, but not statistically different than the other HRSS groups (p > 0.05). DISCUSSION: In previous studies, damage in histopathological examinations after Pt could only be demonstrated long after tourniquet applications such as 24 h and with longer duration of Pt such as 30 min. Structural changes in different Pt application times could be demonstrated at 60 min by electron microscopy and 48 h by light microscopy. In this study, the histopathological effect of Pt application could be demonstrated at the 4th hour after release and HRSS was observed to reduce the damage histopathologically as well as biochemically with its anti-inflammatory and antioxidant effects. It was observed that administration of HRSS either before or following Pt did not cause an alteration statistically. CONCLUSION: HRSS reduces tissue oxidative stress and inflammation on the flap tissue and has a protective effect in Pt applied to the hypospadias model created with a penile flap.

The effects of hydrogen-rich saline solution on intestinal anastomosis performed after intestinal ischemia reperfusion injury.

AIM: We investigated the effects of hydrogen-rich saline solution (HRSS) on intestinal anastomosis performed after intestinal ischemia reperfusion injury (IRI). MATERIALS AND METHODS: Thirty Wistar albino female rats were randomly divided into five groups. Only laparotomy was performed in the Sham group. In the other four groups, an intestinal IRI was performed for 45 min by clamping the superior mesenteric artery. After intestinal IRI, anastomosis was performed by cutting the intestine from the proximal 15 cm of the ileocecal valve at the first and 24th hours. HRSS was given intraperitoneally 5 ml/kg before reperfusion and for four more days in the HRSS1 and HRSS24groups, while no treatment was given to the I/R1 and I/R24 groups. After 5 days, all groups underwent relaparotomy. The anastomotic bursting pressures were measured in all groups, except the Sham group. The tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), myeloperoxidase (MPO) and malondialdehyde (MDA) levels were measured in the tissues taken from the anastomosis line. The tissue sections were evaluated histopathologically and the apoptosis index was determined by applying the TUNEL method. The results were analyzed one-way analysis of variance (ANOVA) and Pearson's chi-squared test. RESULTS: Although the MPO, MDA, IL-6 and TNF-α tissue values were not statistically significant among the groups, the degree of tissue damage and apoptosis levels were lower and the anastomotic bursting pressures values were higher in the HRSS1 and HRSS24 groups compared to the I/R1 and I/R24 groups. CONCLUSION: HRSS is effective in reducing the intestinal damage caused by an IRI: HRSS has the potential to reduce the detrimental effects of intestinal anastomosis performed after an intestinal IRI.

NUT Midline Carcinoma of the Lung in a Six-Year-Old Child.

BACKGROUND: Nuclear protein of the testis (NUT) midline carcinoma is genetically defined by rearrangement of NUT or by immunohistochemical expression of NUT. FINDINGS: A 6-year old child had a NUT midline carcinoma of the lung. Despite aggressive therapy, the child died. CONCLUSION: NUT carcinoma, which can be diagnosed immunohistochemically, remains an aggressive tumor.

Protective effect of hydrogen rich saline solution on experimental ovarian ischemia reperfusion model in rats.

BACKGROUND: The present study aimed to investigate the effects of hydrogen rich saline solution (HRSS) in a rat model of ovarian ischemia-reperfusion injury. METHODS: Thirty-six female Wistar-albino rats were grouped randomly, into six groups of six rats. The groups were classified as: sham (S), hydrogen (H), torsion (T), torsion/detorsion (TD), hydrogen-torsion (HT), and hydrogen-torsion/detorsion (HTD). Bilateral adnexal torsion was performed for 3h in all torsion groups. HRSS was given 5ml/kg in hydrogen groups intraperitoneally. Malondialdehyde (MDA) and glutathione-S-transferase (GST) levels were measured in both the plasma and tissue samples. Tissue sections were evaluated histopathologically, and the apoptotic index was detected by TUNEL assay. The results were analyzed by Kruskal-Wallis and Pearson chi-square tests using computer software, SPSS Version 20.0 for Windows. RESULTS: The MDA levels were higher and GST levels were lower in the torsion and detorsion groups when compared to other groups, but the differences were insignificant (P>0.05). The MDA levels were lower and GST levels were higher in the HT and HTD groups compared with the T and TD groups (P>0.05). Follicular injury, edema, vascular congestion, loss of cohesion and apoptotic index were higher in the torsion groups but decreased in the groups that received HRSS. CONCLUSIONS: According to histopathological and biochemical examinations, HRSS is effective in attenuating ischemia-reperfusion induced ovary injury.

The effect of alfuzosin on renal resistive index, urinary electrolytes and ß2 microglobulin levels and TGF ß-1 levels of kidney tissue in rats with unilateral ureteropelvic junction obstruction.

BACKGROUND: In this study, it was aimed to determine the effects of alfuzosin on experimentally generated unilateral partial ureteropelvic junction obstruction (UPO) in rats. MATERIALS AND METHODS: Thirty Long-Evans rats were randomly allocated into five groups. In control group (C), nothing was performed; in group Sham (S) only laparotomy was done; in Alfuzosin group (A) only alfuzosin was administered for two weeks (10 mg/kg/day p.o.) without any surgery; in UPO group, unilateral UP junction obstruction was produced; and in the Group UPT (ureteropelvic obstruction + treatment), alfuzosin was administered for two weeks (10 mg/kg/day p.o.) in addition to UPO production. Renal pelvic anteroposterior diameters were determined with ultrasonography (USG) and renal arterial resistivity indexes by color Doppler USG. Urine was collected both at the beginning and at the end of the experiment for 24 h in all the groups and at the end of the experiment, blood samples were obtained. Blood and urine electrolytes and TGF-ß1, urine density, urine ß2 microglobulin levels were determined. Renal tissue samples harvested from all of the rats were histopathologically evaluated. Results were determined using one-way ANOVA t-test; p < 0.05 was accepted as significant. RESULTS: Urine density in the UPT group was lower with respect to UPO group and blood electrolytes were preserved as close to normal (p < 0.05). In the UPT group, urine TGF-ß1 and blood TGF-ß1, blood ß2 microglobulin levels and histopathologic damage scores were lower compared to the UPO group (p < 0.05). CONCLUSION: It is shown in this experimental unilateral partial UPO model that alfuzosin treatment prevents obstructive renal damage.

Mutant neurogenin-3 in a Turkish boy with congenital malabsorptive diarrhea.

Congenital diarrheal disorders are caused by disruption in nutrient digestion, absorption, or transport, enterocyte development and functioning, or enteroendocrine functioning. Many additional rare forms of congenital diarrhea are expected to be linked to genes associated with appropriate intestinal fluid and electrolyte balance. Neurogenin-3 mutation, a very rare form of congenital diarrhea, disrupts enteroendocrine cell differentiation and is characterized by malabsorption and the absence of pancreatic islet cells. Diabetes mellitus is typically associated with malabsorptive diarrhea at early onset or at later presentation in neurogenin-3 mutation. Here, we describe the case of an infant with homozygous neurogenin-3 mutation who had severe malabsorptive diarrhea and episodes of hyperchloremic metabolic acidosis after birth. Remarkably, cholestyramine was effective at reducing stool volume and frequency and improved the consistency of the stools; diabetes was not present in this patient.

Ultrasound-guided thyroid nodule fine-needle biopsies--comparison of sample adequacy with different sampling techniques, different needle sizes, and with/without onsite cytological analysis.

INTRODUCTION: The aim of this study was to compare the diagnostic adequacy of thyroid samples obtained by aspiration or capillary biopsy techniques, with 22 or 27 gauge needles, and with or without on-site cytological analysis (OCA). MATERIAL AND METHODS: Four hundred patients with thyroid nodules underwent ultrasound (US)-guided fine-needle biopsies. Patients were divided into eight groups according to needle size (22 vs. 27 gauge), biopsy technique (aspiration vs. capillary), and whether or not OCA was performed. Sample adequacy rates were calculated for each group and subgroups and compared using chi-square tests. RESULTS: When all nodes were evaluated (n = 400), the adequacy rate was significantly greater with the capillary than with the aspiration technique (97% vs. 91.5%, p = 0.032) and when OCA was than was not performed (97% vs. 91.5%, p = 0.032). When only solid nodules were evaluated (n = 205) the adequacy rate was also significantly greater with the capillary than with the aspiration technique (98.9% vs. 89.7%, p = 0.008) and when OCA was than was not performed (97.9% vs. 89.6%, p = 0.014). In contrast, the adequacy rate was similar for 22 and 27 gauge needles (94.2% vs. 93.1%, p = 0.733). CONCLUSIONS: Optimal results were obtained with the capillary technique and OCA. The capillary technique and OCA should be the preferred approach in thyroid nodule biopsy, optimising adequacy rates and patient comfort.

An insight into the relationships between prohepcidin, iron deficiency anemia, and interleukin-6 values in pediatric Helicobacter pylori gastritis.

UNLABELLED: The link between Helicobacter pylori and iron deficiency (ID) or iron deficiency anemia (IDA) has been investigated recently. We suggested that IDA/ID associated with H. pylori infection might be mediated by inflammation-driven hepcidin production. Patients with complaints of recurrent abdominal pain and dyspepsia aged between 7-16 years were included in this study. Patients were divided into two groups according to H. pylori status in upper gastrointestinal endoscopy. Group I who had H. pylori gastritis (n=50) received triple antibiotic therapy. Group II (n=50) who had H. pylori-negative gastritis only received proton pump inhibitor. Thirty healthy children with the similar age and gender were included in the study as a control group. Complete blood count, serum iron levels, iron-binding capacity, ferritin levels, prohepcidin and interleukin-6 (IL-6) values were evaluated in all children at the first visit. Initial tests were repeated after H. pylori eradication. Initial levels of ferritin (p=0.002), prohepcidin (p=0.003), and IL-6 (p=0.004) were found significantly lower in group I compared to group II and the control group. The mean prohepcidin level was lower in the anemic H. pylori-positive group than in non-anemic H. pylori-positive group; however, the difference was not statistically significant. While significant increases in hematocrit and mean corpuscular volume were observed, no significant difference was found in serum ferritin, prohepcidin, or IL-6 level after eradication treatment in H. pylori-positive group. CONCLUSION: H. pylori-induced gastritis appears to cause an increase in prohepcidin levels and a decrease in ferritin levels, supporting our hypothesis; but this relationship has not been proven.

What is the malignancy risk for atypia of undetermined significance? Three years' experience at a university hospital in Turkey.

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) provides uniform diagnostic terminology for communication between pathologists and clinicians. Each diagnostic category is associated with a specific risk of malignancy and a recommendation for its management. The indeterminate diagnostic categories of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) present a major challenge for both pathologists and clinicians. We report our institution's 3 years' experience with the AUS/FLUS category and follow-up of these patients. METHODS: A retrospective analysis was conducted for all thyroid fine-needle aspirations (FNAs) between July 2010 and July 2013. During this period, 9242 nodules from 4916 patients were reported according to the BSRTC guidelines. We adopted the AUS terminology in our practice to refer to both AUS, and FLUS. RESULTS: Of the 4916 patients, 347 (7%) were diagnosed as AUS. The malignancy risk for patients who underwent surgical resection after initial diagnosis of AUS was 22.8%, whereas that for patients who underwent a second FNA and surgical resection was 36%. When we included patients with second FNA and without surgery, the malignancy risk was 15.7%. CONCLUSIONS: The malignancy risk for AUS reported in the present study is consistent with those reported previously and is higher than those anticipated according to the Bethesda System. This supports that a multimodal approach (clinical, radiologic, and cytopathologic) is necessary for the management of thyroid nodules diagnosed as AUS. Therefore, we suggest that the recommendation for repeat FNA following an initial diagnosis of AUS should be based on a multimodal approach for each particular patient.

The effects of melatonin on intestinal adaptation in a rat model of short bowel syndrome.

INTRODUCTION: Short bowel syndrome (SBS) is a clinical condition resulting from the loss of absorptive surface area following resection of 50% or more small bowel. Morphological and functional changes called "intestinal adaptation" occur in the residual intestine. Melatonin exists in the gastrointestinal tract and has effect on mitotic activity. Therefore, we hypothesized that melatonin may have beneficial effects on intestinal adaptation. MATERIALS AND METHODS: A total of 32 male Wistar albino male rats were divided into four groups. In group I (sham-S), small bowel was transected and reanastomosed. In group II (SBS-control), 75% small bowel resection and anastomosis were performed. In group III (SBS-vehicle), after 75% small bowel resection and anastomosis, 2 mL of 5% ethanol in saline was given intraperitoneally once a day. In group IV (SBS-melatonin), after 75% small bowel resection and anastomosis, 300 µg/kg melatonin was given intraperitoneally once a day. After 15 days, small bowels were removed and divided into two segments as jejunum and ileum. Each segment was weight and measured. Histological examination was performed in all samples. Bowel and mucosal weights and DNA/protein ratio were calculated. Apoptotic cells were also identified. RESULTS: The bowel length measurements were statistically longer in group IV. Mucosal and bowel weights were the highest in group IV. The villus height, crypt depth, and the number of mitotic figures were the highest in the jejunum of group IV. Melatonin also gave rise to a significant increase in DNA/protein ratios in group IV. CONCLUSION: According to this study, melatonin significantly enhanced intestinal adaptation.

Eosinophilic esophagitis and anaphylaxis due to cow's milk in an infant.

Food allergies are often seen in infancy and usually show the clinical signs in the form of type I hypersensitivity reaction. However, a combination of food allergies can sometimes be found in the same patient. In this report, we present an 11-month-old infant who had a combination of anaphylaxis and eosinophilic esophagitis induced by cow's milk. Diagnosis of eosinophilic esophagitis is done by examination of esophageal biopsy material histologically. This is a very rare combination of food allergy. Improvement in clinical and histological findings of eosinophilic esophagitis was achieved by removal of cow's milk and dairy products from the infant's diet.

Rectal duplications accompanying rectovestibular fistula: report of two cases.

Rectal duplication (RD) cysts are rare congenital anomalies that can be diagnosed with the presence of another opening in the perineum. They seldom accompany anorectal malformations (ARM). Two cases of RD accompanying ARM at opposite ends of the phenotypic spectrum, are described. A 3-month-old baby and a 2-year-old girl with ARM were scheduled for posterior sagittal anorectoplasty. The infant had an orifice at the anal dimple and the other had an orifice at the vestibulum posterior to the rectovestibular fistula. The infant presented with no other anomalies whereas the older one presented with an unusual coexistence of caudal duplication and caudal regression syndromes. Perioperatively both orifices were found to be related to retrorectal cysts, and were excised. Clinicians should always be alert when dealing with complex malformations. Because these malformations have variable anatomical and clinical presentations, they can represent a diagnostic and therapeutic challenge.

Solid tumors in Turkish children: a multicenter study.

BACKGROUND: This paper presents a detailed incidence study on childhood solid tumors comprising a histopathology-based documentation of benign and malignant lesions. METHODS: The Ankara Pediatric Pathology Working Group collected databases of pediatric solid tumors from six pediatric reference centers in order to analyze the incidence, distribution and some epidemiologic characteristics of the tumors and to establish a multicenter database for further studies. A five-year retrospective archive search was carried out. Excluding epithelial tumors of the skin, leukemia, lymphoreticular system neoplasias, metastatic tumors, and hamartomas, 1362 solid tumors in 1358 patients were classified according to age, sex, localization, histopathology and clinical behavior. RESULTS: The male/female ratio was 0.9; 14.8% (201) of the patients belonged to 0-1 year age group, 20.7% (281) to 2-4 years, 25.9% (352) to 5-10 years, 22.2% (301) to 11-14 years, and 16.4% (223) to 15-18 years. Among all tumors, 708 (52.0%) were malignant, 645 (47.4%) benign tumors, 2 (0.1%) borderline tumors, and 2 (0.1%) unknown behavioral tumors. Malignant tumors were found in 50.2% (357) of female patients and in 54.0% (349) of male patients. A balanced distribution between benign and malignant entities among children under 18 years was observed. Comparison between the age groups revealed malignant cases outnumbered benign cases under 4 years of age while benign tumor numbers increased after 10 years of age. The most common entities in the malignant group were of sympathetic nervous system origin, while soft tissue tumors far outnumbered the others in the benign group. CONCLUSIONS: We conclude that the cancer patterns of children in the Ankara region mostly resemble with those of the western population. This study provides useful information on the diagnosis of solid tumors in children and highlights variations in cancer incidence in different age groups.

Extraskeletal Ewing sarcoma of the mesocolon in a child.

Ewing sarcoma (ES) is a malignant neoplasm usually affecting the skeletal system. Extraskeletal ES is a rare tumor. To date, only 1 case of primary mesocolon ES has been previously reported in an adult. Herein, we present the first case of ES in the mesocolon in a child.