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Dive into the research topics where Bilgehan Yalçın is active.

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Featured researches published by Bilgehan Yalçın.


Journal of Clinical Immunology | 2012

Additional Diverse Findings Expand the Clinical Presentation of DOCK8 Deficiency

Ozden Sanal; Huie Jing; Tuba Turul Ozgur; Deniz Cagdas Ayvaz; Dara M. Strauss-Albee; Sibel Ersoy-Evans; Ilhan Tezcan; Gulten Turkkani; Helen F. Matthews; Goknur Haliloglu; Aysel Yüce; Bilgehan Yalçın; Özay Gököz; Kader Karli Oguz; Helen C. Su

We describe seven Turkish children with DOCK8 deficiency who have not been previously reported. Three patients presented with typical features of recurrent or severe cutaneous viral infections, atopic dermatitis, and recurrent respiratory or gastrointestinal tract infections. However, four patients presented with other features. Patient 1–1 featured sclerosing cholangitis and colitis; patient 2–1, granulomatous soft tissue lesion and central nervous system involvement, with primary central nervous system lymphoma found on follow-up; patient 3–1, a fatal metastatic leiomyosarcoma; and patient 4–2 showed no other symptoms initially besides atopic dermatitis. Similar to other previously reported Turkish patients, but in contrast to patients of non-Turkish ethnicity, the patients’ lymphopenia was primarily restricted to CD4+ T cells. Patients had homozygous mutations in DOCK8 that altered splicing, introduced premature terminations, destabilized protein, or involved large deletions within the gene. Genotyping of remaining family members showed that DOCK8 deficiency is a fully penetrant, autosomal recessive disease. In our patients, bone marrow transplantation resulted in rapid improvement followed by disappearance of viral skin lesions, including lesions resembling epidermodysplasia verruciformis, atopic dermatitis, and recurrent infections. Particularly for patients who feature unusual clinical manifestations, immunological testing, in conjunction with genetic testing, can prove invaluable in diagnosing DOCK8 deficiency and providing potentially curative treatment.


Pediatric Blood & Cancer | 2006

Treatment results of 84 patients with nasopharyngeal carcinoma in childhood

Serhan Küpeli; Ali Varan; Enis Özyar; I. Lale Atahan; Bilgehan Yalçın; Tezer Kutluk; Canan Akyüz; Münevver Büyükpamukçu

To evaluate the clinical characteristics, treatment regimens, survival, and late complications in patients with nasopharyngeal carcinoma.


Journal of Pediatric Hematology Oncology | 2006

Second neoplasms in pediatric patients treated for cancer: a center's 30-year experience.

Kudret Çağlar; Ali Varan; Canan Akyüz; Selek U; Tezer Kutluk; Bilgehan Yalçın; Atahan Il; Münevver Büyükpamukçu

To investigate the incidence and outcome of secondary neoplasms in pediatric patients treated for childhood cancer. Between December 1971 and January 2000, a total of 5859 patients younger than age 17 were diagnosed and treated for childhood cancers in our center. Of this group, 1511 (36%) patients were followed for more than 36 months. These long-term survivors were included in this analysis. Twenty-six patients developed a secondary malignancy with an overall risk of 1.7% in this cohort. The male:female ratio was 17:10, with a median age of 7.66 at diagnosis (range, 2 to 16 y). Four patients (14.8%) with Hodgkin lymphoma; 3 each (11.1%) with retinoblastoma and rhabdomyosarcoma; 2 each (7.4%) with Wilms tumor, Ewing sarcoma, medulloblastoma, ganglioneuroblastoma, and non-Hodgkin lymphoma; and 1 each (3.7%) with ependymoma, nasopharyngeal carcinoma, osteosarcoma, astrocytoma had a secondary malignant disease during the long-term follow-up period. Secondary malignant diseases were osteosarcoma in 6 patients, acute lymphoblastic leukemia in 2, acute myelogenous leukemia in 2, and rare malignant disease in others. Four patients with osteosarcoma developed disease within the radiation field. Osteosarcoma was the most frequently occurring secondary neoplasm. Less toxic treatment modalities should be used to decrease the risk of secondary malignant diseases.


Pediatric Hematology and Oncology | 2006

Infantile hepatic hemangioendothelioma with elevated serum alpha-fetoprotein.

Neriman Sari; Bilgehan Yalçın; Canan Akyüz; Mithat Haliloglu; Münevver Büyükpamukçu

Infantile hemangioendothelioma is the most common hepatic vascular tumor in infants less than 6 months of age, with a prevalence of 1%. Serum α-fetoprotein levels have been used as an important tumor marker for hepatoblastoma, hepatocellular carcinoma, and germ cell tumors. It is rarely elevated in hepatic hemangioendothelioma. The authors report an infant with a hepatic hemangioendothelioma associated with elevation of serum α-fetoprotein who was treated with corticosteroids. In young infants, a solitary hepatic mass and elevated serum AFP level may not always be associated with hepatoblastoma. Infantile hemangioendothelioma must be differentiated by MRI or other radiological techniques before performing invasive procedures.


Pediatric Hematology and Oncology | 2008

Langerhans cell histiocytosis: retrospective analysis of 217 cases in a single center.

Begül Yağcı; Ali Varan; Cağlar M; Figen Soylemezoglu; Arzu Sungur; Diclehan Orhan; Bilgehan Yalçın; Canan Akyüz; Tezer Kutluk; Münevver Büyükpamukçu

Langerhans cell histiocytosis (LCH) is a disorder with unclear etiology and pathogenesis, which is characterized by abnormal clonal proliferation and accumulation of langerhans cells at various tissue and organs. A total of 217 patients with LCH were evaluated retrospectively for clinicopathological features, laboratory findings, treatment modalities, long-term outcome, and factors affecting the outcome. Median age at the time of diagnosis was 3.5 years and male/female ratio was 1.8. The most common complaint at presentation was a bone lesion-related symptom. Fifty percent of the patients younger than 2 years had organ dysfunction (OD). Treatment consisted of surgery, chemotherapy, and radiotherapy alone or in combination. Vinblastine with or without prednisolone was the most common used chemotherapy regimen. Overall (OS) and event-free survival (EFS) rates were 84% and 51.5%, respectively, at an 8-year median follow-up time. Overall survival was significantly lower in patients younger than 2 years of age and patients with OD. The age at diagnosis, pulmonary, liver, or hematological involvement, and elevated acute-phase reactants were found to have a statistically significant effect on the OS or EFS rates.


Annals of Hematology | 2005

Evaluation of thrombotic children with malignancy

Selma Unal; Ali Varan; Bilgehan Yalçın; Münevver Büyükpamukçu; Aytemiz Gurgey

The purpose of this study was to evaluate inherited and acquired prothrombotic risk factors among children with malignancies who have thrombosis and emphasize the importance of inherited prothrombotic risk factors. Thirty-seven consecutive children with thrombosis and malignancy were included in this study. The patients were evaluated separately for time of development of thrombosis, insertion of a central venous line (CVL), history of l-asparaginase usage, and recent infections. Prothrombotic risk factors such as factor V G1691A and prothrombin G20210A mutation, protein C, protein S, antithrombin III deficiencies, factor VIII and lipoprotein(a) elevation, and antiphospholipid antibodies were analyzed for all patients. Of 387 children with thrombosis, 37 (9.5%) had a malignancy. Thrombosis was detected in 9 patients at the time of diagnosis, during maintenance therapy in 25 patients, and after the discontinuation of treatment in 3 patients. One or two additional prothrombotic risk factors other than l-asparaginase therapy and insertion of central venous lines were present in 20 of these patients (54%). It was found that eight patients had the factor V G1691A mutation in the heterozygote state. One of them had the factor V G1691A mutation associated with a history of infection and one patient had the factor V G1691A mutation associated with factor VIII elevation. One had the the prothrombin G20210A mutation in the heterozygote state, four had lipoprotein(a) elevation, two had factor VIII elevation, one had a decreased protein S level, one had a decreased protein C level, one had antiphospholipid positivity, and two had histories of infection. Malignancy is an important risk factor for the development of childhood thrombosis. However, the risk of thrombosis increases when accompanied by additional prothrombotic risk factors. For this reason, especially children with malignancy and at high risk for the development of thrombosis, such as those who have received l-asparaginase or a replaced CVL during their therapy, might be screened for additional prothrombotic risk factors and appropriate measures might be taken to prevent the development of thrombosis.


Pediatric Blood & Cancer | 2011

Posterior fossa syndrome after posterior fossa surgery in children with brain tumors.

Serhan Küpeli; Bilgehan Yalçın; Burcak Bilginer; Nejat Akalan; Pınar Haksal; Münevver Büyükpamukçu

Posterior fossa syndrome (PFS) is defined as the temporary and complete loss of speech after posterior fossa surgery. The goal of this study was to identify incidence and risk factors for PFS and to determine accompanying neurobehavioral and psychologic problems.


Pediatric Radiology | 1992

Wolman's disease: Ultrasonographic and computed tomographic findings

Mustafa Ozmen; N. Aygün; I. Kiliç; L. Kuran; Bilgehan Yalçın; A. Besim

Acid lipase deficiency which is an inborn error of lipid metabolism leads to an abnormal accumulation of cholesteryl esters and triglycerides in many tissues. It is manifested in two clinical forms: Wolmans disease (WD) which is fatal in infancy and cholesteryl ester storage disease (CESD) which is a milder form and usually presented in adulthood. An infant with a clinical diagnosis of WD was examined with CT and ultrasound. Where as CT showed an enlarged liver with decreased density and heavily calcified adrenal glands, ultrasound revealed an enlarged liver with normal echogenicity, adrenal calcification and thickening of bowel loops. Bowel wall thickening in WD was not demonstrated in the literature before with any imaging modality.


Pediatrics International | 2005

Primary malignant skin tumors in children: Etiology, treatment and prognosis

Ali Varan; Aytaç Gököz; Canan Akyüz; Tezer Kutluk; Bilgehan Yalçın; Yavuz Köksal; Münevver Büyükpamukçu

Abstract Objective : The aim of the study was to evaluate the etiology, treatment and prognosis of the malignant skin tumors in children.


Pediatric Hematology and Oncology | 2005

Intracranial involvement in Hodgkin's disease.

Canan Akyüz; Bilgehan Yalçın; I. Lale Atahan; Ali Varan; M. Tezer Kutluk; Münevver Büyükpamukçu

The authors report 3 cases of Hodgkins disease with intracranial involvement. The patients were 4, 12, and 15 years old (male/female = 1/2). Initially, they were treated with ABVD or COPP chemotherapies and low-dose involved field radiotherapy. Intracranial recurrences occurred 27, 40, and 42 months after initial diagnosis, respectively. Two patients experienced convulsions and the other complained of diplopia. The metastatic lesions were located supratentorially with CT or MRI. Despite initial response achieved following systemic chemotherapy and external irradiation to cranial lesions, all patients died with disseminated disease. In patients with intracranial involvement of Hodgkins disease, prolonged disease-free survival may be achieved by combined modality treatment.

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