Metachronous Wilms Tumor, Glioblastoma, and T-cell Leukemia in an Child With Constitutional Mismatch Repair Deficiency syndrome due to Novel Mutation in MSH6 (c.2590G>T).

Constitutional mismatch repair deficiency (CMMRD) is an autosomal recessively inherited childhood cancer predisposition syndrome results from biallelic germline mutations affecting the key DNA mismatch repair gene: MLH1, MSH2, MSH6, or PMS2. CMMRD is associated with a high risk of developing early onset of central nervous system tumors, hematologic, and intestinal tract tumors. Clinical manifestations, genetic screening, and cancer prevention strategies are limited. In this report we present a patient with metachronous Wilms tumor, glioblastoma, and acute T-cell lymphoblastic leukemia. He had cutaneous features of neurofibromatosis type 1 (NF1). Molecular testing revealed a novel homozygous mutation in MSH6 (c.2590G>T; p.G864*) that has not been reported previously. CMMRD should be considered in patients with cutaneous features similar to NF1 if tumor is found other than expected tumors in NF, early onset cancer, and strong family history of cancer.

Vandetanib in a Child Affected by Neurofibromatosis Type 1 and Medullary Thyroid Carcinoma with Both NF1 and Homozygous RET Proto-oncogen Germ-line Mutations

Cases of neurofibromatosis type 1 (NF1)-associated medullary thyroid carcinoma (MTC) or C-cell hyperplasia are rarely associated with other endocrine tumors or cases with a multiple endocrine neoplasia type 2. In these patients, mutations were detected in the NF1 gene but no mutations were detected in the RET gene. Although vandetanib has been shown to improve progression-free survival in adults with advanced MTC, data in pediatric patients are limited. Herein, we report the use and outcome of vandetanib in a pediatric MTC case in which NF1 gene and RET proto-oncogen mutation were identified together.

Temporal bone hemangioendothelioma as a rare vascular tumor in childhood: case report and review of the literature.

BACKGROUND: Hemangiondothelioma is a rare vascular tumor that can occur in the bone. Temporal bone involvement has been reported extremely rare in the literature. CASE: Radiological examination of a one-year-old girl who was admitted due to facial paralysis revealed vascular tumor of the temporal bone and Galen vein aneurysm. Pathological examination showed retiform hemangioendothelioma. She was treated with propranolol, prednisolone, vincristine, and endovascular embolization followed by oral sirolimus. With sirolimus treatment, a partial response was obtained first, then the tumor remained stable and sirolimus treatment was discontinued. No progression was observed in the disease after discontinuation of treatment. CONCLUSION: In this article, a case of hemangioendothelioma originating from the temporal bone is discussed in the light of other case reports in the literature.

Bone marrow involvement in pediatric malignancies: a comparison study of Positron emission tomographycomputed tomography and bone marrow biopsy.

BACKGROUND AND OBJECTIVES: The comparison of Positron emission tomography- computed tomography (PETCT) and bone marrow biopsy (BMB) modalities in detecting bone marrow disease is an up to date research topic. In this study, we aimed to compare the results of PET-CT and BMB procedures in detecting bone marrow involvement in pediatric malignancies. METHOD: At the time of diagnosis, PET-CT imaging and BMB performed patients` data were evaluated, retrospectively. Malign diagnoses were Hodgkin's lymphoma in 23 (30.7%), non-Hodgkin's lymphoma in 20 (26.7%), neuroblastoma in 11 (14.7%), Ewing sarcoma in 10 (13.7%), Langerhans cell histiocytosis in 6 (8%), and rhabdomyosarcoma in 5 (6.6%) patients. RESULTS: Bone marrow involvement was detected in 39 (52%) of 75 patients. Bone marrow involvement was identified by both PET-CT and BMB in 18 (46.1%) patients, by only PET-CT in 12 (30.7%) patients, by only BMB in 9 (23%) patients. The sensitivity of PET-CT was 66%, specificity was 75%, positive predictive value was 60%, and negative predictive value was 80%. Sensitivity, spesificity, positive and negative predictive values of PETCT were different in before mentioned malignancy groups. CONCLUSION: PET-CT may not have high sensitivity and specificity to identify bone marrow involvement for each type of cancer. The approach of using bone marrow biopsy and PET-CT as complementary modalities seems reliable.

Mucoepidermoid Carcinoma in Warthin Tumor of the Parotis in Childhood: A Case Report and Review of the Literature.

Mucoepidermoid carcinoma arising in Warthin tumor of the parotid gland is an extremely rare entity. This is so far described only in the adult age group, and only one patient has been reported in the pediatric age group until today. Herein, we describe our patient and review the literature. This was a case of a 9-year-old girl admitted with a painless swelling in the left side of her face for at least 2 weeks. Histopathologic examination of total parotidectomy specimens revealed mucoepidermoid carcinoma arising in the Warthin tumor. This case is the youngest patient reported to date.

Metachronous Synovial Sarcoma After Treatment of Mixed Germ Cell Tumor in a Child with Complete Gonadal Dysgenesis.

Patients with complete XY gonadal dysgenesis (GD) show a high predisposition to germ cell tumors (GCT). Patients with coexistence of GCT and GD have been reported previously. Here we present a 15-year-old girl with mixed GCT and GD who also developed an intra-abdominal synovial sarcoma one year after the treatment. This is the first report, to our knowledge, of synovial sarcoma associated with XY GD.

Primary pulmonary Langerhans cell histiocytosis associated with smoking in an adolescent boy.

Pulmonary Langerhans cell histiocytosis (PLCH) is a well known entity in adults but is exceedingly rare in children. It is better described in adults than in children. Smoking is a major etiological factor in adulthood. We report a case of a previously healthy 16-year-old male with a history of cigarette smoking, who presented with cough with sputum, breathlessness, easy fatigability and loss of appetite for two weeks. He was first diagnosed with bronchiectasis according to the cystic pulmonary changes demonstrated by computed tomography. After appropriate treatment, there was no sign of clinical improvement. A lung biopsy confirmed Langerhans cell histiocytosis (LCH). The definitive diagnosis was isolated pulmonary LCH. PLCH should be considered in the etiology of cystic lung diseases. Isolated pulmonary LCH is rare so such cases are needed to be reported and followed-up to understand the treatment response and course of this illness.