Araştırma Çıktıları

Permanent URI for this communityhttps://hdl.handle.net/11443/931

Browse

Author: search.filters.author.Guduk, Mustafa

Search Results

Now showing 1 - 8 of 8
  • No Thumbnail Available
    Item
    High-resolution Whole-Genome Analysis of Skull Base Chordomas Implicates FHIT Loss in Chordoma Pathogenesis
    (NEOPLASIA PRESS, 2012-01-01) Diaz, Roberto Jose; Guduk, Mustafa; Romagnuolo, Rocco; Smith, Christian A.; Northcott, Paul; Shih, David; Berisha, Fitim; Flanagan, Adrienne; Munoz, David G.; Cusimano, Michael D.; Pamir, M. Necmettin; Rutka, James T.
    Chordoma is a rare tumor arising in the sacrum, clivus, or vertebrae. It is often not completely resectable and shows a high incidence of recurrence and progression with shortened patient survival and impaired quality of life. Chemo-therapeutic options are limited to investigational therapies at present. Therefore, adjuvant therapy for control of tumor recurrence and progression is of great interest, especially in skull base lesions where complete tumor resection is often not possible because of the proximity of cranial nerves. To understand the extent of genetic instability and associated chromosomal and gene losses or gains in skull base chordoma, we undertook whole-genome single-nucleotide polymorphism microarray analysis of flash frozen surgical chordoma specimens, 21 from the clivus and 1 from C1 to C2 vertebrae. We confirm the presence of a deletion at 9p involving CDKN2A, CDKN2B, and MTAP but at a much lower rate (22\%) than previously reported for sacral chordoma. At a similar frequency (21\%), we found aneuploidy of chromosome 3. Tissue microarray immunohistochemistry demonstrated absent or reduced fragile histidine triad (FHIT) protein expression in 98\% of sacral chordomas and 67\% of skull base chordomas. Our data suggest that chromosome 3 aneuploidy and epigenetic regulation of FHIT contribute to loss of the FHIT tumor suppressor in chordoma. The finding that FHIT is lost in a majority of chordomas provides new insight into chordoma pathogenesis and points to a potential new therapeutic target for this challenging neoplasm. Neoplasia (2012) 14, 788-798
  • Thumbnail Image
    Item
    Shunt Valve Rupture in Ventriculoperitoneal Shunt Failure
    (ELSEVIER SCIENCE INC, 2021-01-01) Guduk, Mustafa; Akbas, Ahmet; Tuzunalp, Muruvvet Ayten; Berikol, Gurkan; Eksi, Murat Sakir
    BACKGROUND: Shunt complications are common despite advances in surgial techniques and shunting technology. Proximal and/or distal catheter malfunctions are detected in pediatric and adult patients. However, valve dysfunction is rare in such cases. CASE DESCRIPTION: A 24-year-old woman presented with a history of veotriculostomy and ventriculoperitoneal shunt (VPS) secondary to hydrocephalus concomitant with Dandy-Walker syndrome. She has had undulant headache and vision loss episodes in both eyes for 15 days. Her VPS valve was normal when manually checked, and the VPS was observed as intact on x-ray and computed tomography scan. She had high-grade papilledema in both eyes with an optical coherence tomography scan value of 55/99. Lumbar puncture was performed. Cerebrospinal fluid opening pressure was 560 mm H2O under sedation. VPS exploration surgery was performed. There was a tiny defect over the shunt valve from where clear cerebrospinal fluid was leaking. We revised the old VPS valve with a new valve of 1.5 regular pressure. Her vision improved shortly after the surgery. CONCLUSIONS: This case is a very rare example of shunt valve dysfunction that required further investigation and a new valve replacement even though the preoperative imaging was normal.
  • No Thumbnail Available
    Item
    Microsurgical and Functional Linguistic Anatomy of Cerebral Basal Ganglia
    (GALENOS PUBL HOUSE, 2020-01-01) Guduk, Mustafa; Cirak, Musa; Bozkurt, Baran; Yagmurlu, Kaan
    Introduction: The central core of the cerebral hemispheres is located on the medial side of the insular cortex. It is made up of basal ganglia and white matter tracts. The basal ganglia and their white matter connections serve important motor, sensorial, psychological, endocrinological and cognitive functions. Insular gliomas and other deeply located lesions can cause severe morbidity by affecting the basal ganglia and their connections. Hence, a thorough understanding of the anatomy of that area is needed for surgical planning on the insular area. Methods: We dissected and photographed the insular cortex and basal ganglia in five human cadavers via white matter dissection techniques from lateral to medial side. Results: The structures and connections of the insular cortex and basal ganglia are documented and presented with their functional correlations during the dissections. Conclusion: Our results will guide the strategy and planning of surgery for the insula and basal ganglia. Additionally, they will be helpful in the follow-up and prediction of morbidities of lesions located in that area.
  • No Thumbnail Available
    Item
    Pituitary Colloid Cyst
    (LIPPINCOTT WILLIAMS \& WILKINS, 2017-01-01) Guduk, Mustafa; Sun, Halil Ibrahim; Sav, Murat Aydin; Berkman, Zafer
    Colloid cysts appear most commonly in the third ventricle, their occurrence in the sellar region is uncommon. The authors report a female patient with a pituitary colloid cyst. She was diagnosed incidentally with a sellar lesion by a routine paranasal computed tomography examination performed for planning of a dental implant surgery. Radiologic examinations revealed a pituitary lesion that was removed by transnasal transsphenoidal route. Her pathologic examination revealed that the lesion was a colloid cyst. Although rare, colloid cysts should be considered in the differential diagnosis of pituitary lesions
  • Thumbnail Image
    Item
    The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study
    (MDPI, 2021-01-01) Cevik, Orhun Mete; Usseli, Murat Imre; Babur, Mert; Unal, Cansu; Eksi, Murat Sakir; Guduk, Mustafa; Ovalioglu, Talat Cem; Aksoy, Mehmet Emin; Pamir, M. Necmettin; Bozkurt, Baran
    Cerebral stroke continues to be one of the leading causes of mortality and long-term morbidity
  • Thumbnail Image
    Item
    Pterional and Unifrontal Approaches for the Microsurgical Resection of Olfactory Groove Meningiomas: Experience with 61 Consecutive Patients
    (TURKISH NEUROSURGICAL SOC, 2017-01-01) Guduk, Mustafa; Yener, Ulas; Sun, Halil Ibrahim; Hacihanefioglu, Mehmet; Ozduman, Koray; Pamir, M. Necmettin
    AIM: Olfactory groove meningiomas make up 4 to 13\% of meningiomas. The first line treatment of meningiomas is surgery, but the extent and types of approaches advised for olfactory groove meningiomas are diverse, from aggressive skull base approaches to standard or minimally invasive craniotomies and endoscopic approaches. We retrospectively reviewed our series of olfactory groove meningiomas that were operated microsurgically by standard pterional or unifrontal approaches. MATERIAL and METHODS: Our series of 61 olfactory groove meningioma patients operated through pterional or unifrontal approaches between March 1987 and September 2015 was reviewed and the clinical data, radiological findings, surgical treatment and clinical outcomes of the patients were retrospectively analyzed. RESULTS: Sixty-three craniotomies were performed in total. Pterional and unifrontal approaches were used in 38 (60.3\%) and 25 (39.7\%) surgical procedures, respectively. Overall, gross total tumor resection was achieved in 59 (93.7\%) cases. Complications were seen in 8 cases, and 2 of these patients underwent reoperation. Three of the 4 patients where only subtotal resection could be achieved underwent gamma knife radiosurgery. CONCLUSION: Pterional and unifrontal approaches, which are familiar and standard for neurosurgeons, can accomplish high rates of total resection with acceptable complication and recurrence rates for the treatment of olfactory groove meningiomas.
  • Thumbnail Image
    Item
    Chordoma: Immunohistochemical Analysis of Brachury
    (TURKISH NEUROSURGICAL SOC, 2018-01-01) Sun, H. Ibrahim; Guduk, Mustafa; Gucyetmez, Bulent; Yapicier, Ozlem; Pamir, M. Necmettin
    AIM: Chordomas are rare, slow growing but locally aggressive malignancies of the axial skeleton. Skull base chordomas, due to their intricate anatomical localization, pose significant challenges to managing physicians. In classical and chondroid chordomas, the disease course cannot be reliably determined using only morphological criteria. Brachyury (T Gene) was shown to play a central role in chordoma pathogenesis and several studies also showed that this gene also carries potential as a prognostic biomarker. This study aims to correlate Brachyury expression with the clinical course in surgically treated skull base chordomas. MATERIAL and METHODS: Chordoma tumor samples from 14 patients with skull base chordomas, diagnosed using histopathological and immunohistochemistry criteria (epithelial membrane antigen (EMA), S100, pan cytokeratin (panCK)) were retrospectively analyzed for Brachyury expression using immunohistochemistry. Brachyury expression was graded using a 4 point semi-quantitative scoring system. Focal (grade II) and diffuse staining (grade III) were considered as overexpression. Patient recurrence-free survival and total survival were compared between Brachyury overexpressing and non-overexpressing groups using Kaplan-Meier survival analysis. RESULTS: Among the stained tumor samples, 85.7\% were positive for brachyury expression. In both groups, there was one sample that was negative. We did not observe any significant difference among the groups for staining, grade and percentage of brachyury positive cells. CONCLUSION: Brachyury expression in tumor samples is not a sensitive indicator of prognosis in chordomas.
  • Thumbnail Image
    Item
    Intrasellar arachnoid cyst: A case report and review of the literature
    (ELSEVIER SCI LTD, 2016-01-01) Guduk, Mustafa; HamitAytar, Murat; Sav, Aydin; Berkman, Zafer
    INTRODUCTION: Arachnoid cysts (ACs) are frequently found on intracranial imaging studies but intrasellar arachnoid cysts are rarely encountered. PRESENTATION OF CASE: We present a 49-year old patient who had headaches for 6 months and cystic sellar mass was found in his cranial imaging. We operated him by transnasal transsphenoidal route. Our intraoperative diagnosis was an arachnoid cyst and pathologic studies verified our observation. He did well postoperatively and after a 1 year follow-up he was left free from future follow-ups. DISCUSSION: As common cystic lesions occupying the sellar region can simulate ACs both clinically and radiologically, neurosurgeon can fail to include ACs in making the initial diagnosis preoperatively. CONCLUSION: Although a rare entity, arachnoid cysts should be considered in the differential diagnosis of sellar region. (C) 2016 Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.