Ceyhun Bozkurt

Regression of Symptomatic Multiple Cardiac Rhabdomyomas Associated with Tuberous Sclerosis Complex in a Newborn Receiving Everolimus

UNLABELLED Cardiac rhabdomyoma is the most common primary cardiac tumor, is considered to be a hamartoma of developing cardiac myocytes. Cardiac rhabdomyoma is associated with tuberous sclerosis complex (TSC) in 50-86% of cases. Mutations in TSC-1/TSC-2 genes result in increased mammalian target of rapamycin (mTOR) pathway activation responsible for the hamartomatous lesions of tuberous sclerosis complex. Therapy with mTOR inhibitors is currently under investigation as a treatment option for tumors associated with TSC. In this report we present a case with multiple symptomatic rhabdomyomas associated with tuberous sclerosis complex, deemed to be ineligible for surgical removal, treated with everolimus (mTOR inhibitor). CONCLUSION As we observed in our patient, in cases with inoperable symptomatic rhabdomyomas associated with TSC, everolimus, an mTOR inhibitor, may be the treatment of choice, which should be confirmed with additional studies.

Single-center experience with sirolimus therapy for vascular malformations.

ABSTRACT Vascular malformations (VMs) are described as congenital malformations of the vasculature derived from capillaries, veins, lymphatic vessels, arteries, or a combination of these vessels. They can cause significant morbidity resulting from soft tissue hypertrophy-related disfiguration, bony abnormalities, and even organ compromise. They are usually treated with various interventional procedures to achieve local control; however, the chance of success decreases as the anatomical distribution of the malformation widens. Unfortunately, medical treatment options have been quite limited in these patients. Sirolimus is an antiangiogenetic and antiproliferative pharmacologic agent that has been used for the management of VM in the last decade. We report 6 pediatric patients (4 with capillary lymphaticovenous malformations, 1 with lymphaticovenous malformation, and 1 with venous malformation) seen at our clinic within the last 2 years with lesions covering wide anatomical areas. After the patients had unsuccessfully undergone various treatments at various centers, they were treated at our facility with peroral sirolimus. The mean duration of treatment was 13 months, but in 3 patients, tapered dosing continues. Five patients achieved partial responses. The response to sirolimus treatment increased as the lymphatic component of the VM increased. All patients tolerated sirolimus well; side effects were acceptable. Sirolimus is a safe and effective medical treatment for widely distributed VMs with significant lymphatic components and no further local treatment option.

Vitamin B12 Deficiency Mimicking Acute Leukemia in a Child

Tanyildiz HG, Malbora B, Yesil S, Candir MO, Bozkurt C, Sahin G. Vitamin B12 Deficiency Mimicking Acute Leukemia in a Child. Deficiency of vitamin B12 is an important cause of megaloblastic anemia and bone marrow depression. Morphological and functional changes in bone marrow are observed related with vitamin B12 deficiency. Most importantly dysplastic changes can be mistaken as myelodysplastic syndrome or acute leukemia. In adult cases of vitamin B12 deficiencies mimicking acute leukemia were reported. Our case is an alerting example of vitamin B12 deficiency in children mimicking acute leukemia with dysplastic findings.

Successful Treatment of Macroglossia Due to Lymphatic Malformation With Sirolimus.

Objective: To evaluate the effectiveness and safety of sirolimus therapy in a child with macroglossia due to lymphatic malformation. Methods: Sirolimus treatment was applied to the patient with an initial dosing of 0.8 mg/m2 per dose, administered orally, twice daily at approximately 12-hour intervals. Results: After 9 months of sirolimus therapy, there was a nearly complete resolution of lymphatic malformation. The last evaluation was performed 6 months after withdrawal of treatment, and the lesion had almost completely resolved. Conclusion: This article presents a novel approach to the treatment of lymphatic malformation of the tongue using sirolimus, which appears to be safe and effective for the management of complex cases.

Serum Ca 125 levels in children with acute leukemia and lymphoma

Ca 125 is a tumor marker for the diagnosis and monitoring of ovarian carcinoma. We investigated serum Ca 125 levels in 44 children with leukemia and 59 children with lymphoma at initial presentation and 4 weeks after chemotherapy. Serum Ca 125 levels were measured chemilumimetrically with a sandwich enzyme-linked immunosorbent assay. The incidence of elevated serum Ca 125 levels was significantly higher in children with leukemia (14 children) and lymphoma (26 children) than in the healthy children (2 children). In the patients with non-Hodgkins lymphoma (NHL) who had abdominal involvement and/or serous membrane involvement (ascides, pleural, pericardial effusion) at presentation, serum Ca 125 levels were significantly higher than in the patients without abdominal and/or serosal involvement. Serum Ca 125 levels were impressively increased in the patients with Burkitts lymphoma (BL) in whom abdominal and/or serous membrane involvement were observed more frequently than the other types of lymphoma. The increased serum Ca 125 levels in the patients returned to normal 4 weeks after chemotherapy when they achieved complete remission. In conclusion, serum Ca 125 seems to be a good indicator for serous membrane involvement and it seems to be a promising tumor marker in the assessment of therapeutic response in children with leukemia and NHL.

Hemostatic side effects of high-dose methotrexate in childhood acute lymphoblastic leukemia.

The purpose of this study is to investigate the hemostatic side effects of HDMTX. Between 2001 and 2002, 20 children with acute lymphoblastic leukemia at the Dr. Sami Ulus Childrens Hospital, Department of Pediatric Hematology and Oncology, treated according to the St. Jude ALL XIII protocol were eligible to this study. Methotrexate at a dose of 2 g/m2 was infused over 24 hours. Coagulation screening studies included prothrombin time (PT), APTT, fibrinogen, fibrin degradation product (D-Dimer), factor II, factor V, factor VII, factor VIII, factor IX, factor X, PC, PS, AT-III determinations before HDMTX therapy (PreT), 1 day after (PostT1D), and 1 week after (PostT1W) the end of the HDMTX infusion. We found that PT and APTT were prolonged, PC, PS, and AT-III levels were decreased with a slight increase in D-Dimer 1 day after the administration of HDMTX and all of them returned to the normal levels by 7 days. In addition we found that FVII, FIX, FX were significantly decreased 1 day after therapy and normalised by 7 days.

EXPRESSION OF MATRIX METALLOPROTEINASE-9 (MMP-9) AND TISSUE INHIBITOR OF MATRIX METALLOPROTEINASE (TIMP-1) IN TISSUES WITH A DIAGNOSIS OF CHILDHOOD LYMPHOMA

Matrix metalloproteinases (MMP) are enzymes involved in the reconfiguration of the microenvironment by means of degrading the extracellular matrix and have more than 20 subgroups containing zinc. Proteins that serve as the inhibitors of these enzymes are called tissue inhibitors of matrix metalloproteinase (TIMP). These enzymes have been shown to be active in a wide range of processes, from wound recovery to fetus development, heart diseases, and spread of malignant diseases. The aim of this study was to investigate whether there is a relationship between the type, stage, and prognosis of childhood lymphoma subjects and matrix metalloproteinase type-9 (MMP-9) and its inhibitor, tissue inhibitor of matrix metalloproteinase type-1 (TIMP-1). Paraffin blocks of childhood patients diagnosed with non-Hodgkin lymphoma (n = 23), Hodgkin lymphoma (n = 14), or reactive lymphadenopathy (n = 12) were retrospectively immunohistochemically stained with MMP-9 and TIMP-1 stains and whether there was a relationship between the degree of staining and the type, tumor stage, and prognosis of the disease was investigated. Moderate and high degrees of MMP-9 staining were detected in 94.6% of the lymphoma patient tissues and a slight TIMP-1 staining was detected in 21.6% of the lymphoma patient tissues. No relationship was observed between the degree of these staining patterns and the type, tumor stage, and prognosis of the disease. This study indicates that the equilibrium between MMP-9 and TIMP-1 is important in lymphomas in addition to all the physiological and pathologic events although MMP-9 and the TIMP-1 staining patterns are not related to the tumor stage, prognosis, and type of the disease. Larger series of patients are needed to determine the prognostic value of MMP-9 and TIMP-1 in childhood lymphoma.

A case of neuroblastoma in DICER1 syndrome: Chance finding or noncanonical causation?

DICER1 syndrome is an inherited disorder associated with at least a dozen rare, mainly pediatric‐onset tumors. Its characterization remains incomplete. Some studies suggested that neuroblastoma (NB) may be involved in this syndrome. Here, we describe the case of a 14‐year‐old female presenting with a multinodular goiter (MNG) and a collision tumor composed of NB and cystic nephroma (CN). She is a carrier of a deleterious germline mutation in exon 23 of DICER1 and harbored different somatic mutations in the CN and MNG. However, no second hit was found in the NB, questioning its status as a DICER1‐related tumor.

The Diagnostic Value of Hepatic Arterial Velocity in Venoocclusive Disease After Pediatric Hematopoietic Stem Cell Transplantation

The aim of this study was to determine usefulness of measurements of maximal systolic velocity of the hepatic artery with Doppler ultrasonography in the diagnosis of venoocclusive disease (VOD) after hematopoietic stem cell transplantation. We prospectively obtained 5 sonograms per patient: pretransplantation, day +1, +7, +14, and +28 on 36 nonconsecutive children who underwent hematopoietic stem cell transplantation. We examined the hepatic artery, the portal, hepatic and splenic veins, the thickness of the gallbladder wall, the presence of ascites, and the liver and spleen size. The diagnosis of VOD was based on clinical and laboratory data. Patients were divided into 2 groups: those with VOD (n=18) and those without VOD (n=18). The variance of 2 groups was analyzed. Vmax of the hepatic artery had a strong correlation with clinical VOD diagnosis (P<0.001). There was no statistically significant difference in the other Doppler parameters. The results of our study showed that the measurement of Vmax of the hepatic artery can provide important support in the diagnosis of VOD and can be useful in the follow-up of treatment response.

A Rare Presentation of Paraovarian Sclerosing Stromal Tumor with High Mitotic Activity

BACKGROUND Sclerosing stromal tumor is an extremely rare type of benign ovarian sex cord stromal tumor. CASE The benign characteristic of this tumor is well known but we present an uncommon case of paraovarian sclerosing stromal tumor with high mitotic activity. RESULTS AND CONCLUSION Despite this potential malignancy, our patient was treated successfully with enucleation only.