Ebubekir AKPINAR

Dr. Ebubekir AKPINAR

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 July 2021 in Journal of Korean Neurosurgical Society
Verified
Journal Article
Open access
PDF file
BEBuruc Erkan
Buruc Erkan
OBOzan Barut
Ozan Barut
AAAhmet Akbas
Ahmet Akbas
EAEbubekir AKPINAR
Ebubekir AKPINAR
YAYasemin Sefika Akdeniz
Yasemin Sefika Akdeniz
OGOmur Gunaldi
Omur Gunaldi
The endoscopic endonasal transsphenoidal approach is a widely-used method for the surgical treatment of pituitary adenomas. We aimed to evaluate the results of endoscopic surgery by comparing preoperative classification methods and investigating their relationship with postoperative resection and remission rates and complications. We retrospectively reviewed the medical records of 236 patients (118 males) who underwent surgery for pituitary adenomas. Preoperative Knosp classification, tumor size (TS), suprasellar extension (SSE), postoperative resection and remission rates, and complications were evaluated. The follow-up period was 3 months to 6 years. The patients’ ages ranged between 16 and 84 years. Endocrinologically, 114 patients (48.3%) had functional adenoma (FA), and 122 patients (51.7%) had non-functional adenoma (NFA). Among the FA group, 92 (80.7%) showed remission. A statistically significant difference was found between patients with and without remission in terms of the Knosp, TS, and SSE classifications (p<0.01). Knosp, TS, and SSE classification grades were found to be correlated with the resection rates (p<0.01). Meningitis was seen in seven patients (3.0%), diabetes insipidus in 16 (6.9%; permanently in two [0.9%]), and rhinorrhea in 19 (8.1%). Thirty-six patients (15.3%) developed pituitary insufficiency and received hormone replacement therapy. The resection categories and remission rates of FAs were directly proportional to the adenoma sizes and Knosp grades, while the degree of suprasellar growth further complicated resection and remission rates. Adenoma sizes less than 2 cm and SSEs less than 1 cm are associated with favorable remission and resection rates.

1 March 2024 in Journal of Korean Neurosurgical Society
Verified
Journal Article
Open access
PDF file
BEBuruç Erkan
Buruç Erkan
MBMuhammed Bayındır
Muhammed Bayındır
EAEbubekir AKPINAR
Ebubekir AKPINAR
OTOsman Tanrıverdi
Osman Tanrıverdi
OHOzan Haşimoğlu
Ozan Haşimoğlu
EHEsra HATIPOGLU
Esra HATIPOGLU
Objective : Postoperative data on Cushing’s disease (CD) are equivocal in the literature. These discrepancies may be attributed to different series with different criteria for remission and variable follow-up durations. Additional data from experienced centers may address these discrepancies. In this study, we present the results obtained from 96 endoscopic transsphenoidal surgeries (ETSSs) for CD conducted in a well-experienced center.Methods : Pre- and postoperative data of 96 ETSS in 87 patients with CD were included. All cases were handled by the same neurosurgical team between 2014 and 2022. We obtained data on remission status 3−6 months postoperatively (medium-term) and during the latest follow-up (long-term). Additionally, magnetic resonance imaging (MRI) and pathology results were obtained for each case.Results : The mean follow-up duration was 39.5±3.2 months. Medium and long-term remission rates were 77% and 82%, respectively. When only first-time operations were considered, the medium- and long-term remission rates were 78% and 82%, respectively. The recurrence rate in this series was 2.5%. Patients who showed remission between 3−6 months had higher longterm remission rates than did those without initial remission. Tumors >2 cm and extended tumor invasion of the cavernous sinus (Knosp 4) were associated with lower postoperative remission rates.Conclusion : Adenoma size and the presence/absence of cavernous sinus invasion on preopera-tive MRI may predict long-term postoperative remission. A tumor size of 2 cm may be a supporting criterion for predicting remission in Knosp 4 tumors. Further studies with larger patient populations are necessary to support this finding.

1 January 2026 in Endocrine Journal
Verified
Journal Article
Closed access
AOAysel Unver Ozkahraman
Aysel Unver Ozkahraman
MYMerve Korkmaz Yilmaz
Merve Korkmaz Yilmaz
HKHüseyin Karatay
Hüseyin Karatay
SBSidar Bagbudar
Sidar Bagbudar
EAEbubekir AKPINAR
Ebubekir AKPINAR
EHEsra HATIPOGLU
Esra HATIPOGLU
Amyloid spherule-containing prolactinomas are rare entities associated with dopamine agonist (DA) resistance and aggressive behaviour. We report a giant amyloid spherule-containing prolactinoma with a substantial tumour burden and markedly elevated prolactin levels, highlighting novel multimodal therapeutic strategies. A 49-year-old man presented with headache and visual disturbance. Imaging revealed a giant pituitary macroadenoma (63 × 84 × 46 mm) with Knosp grade 4 cavernous sinus invasion and clivus erosion. Laboratory investigations revealed marked hyperprolactinemia (prolactin (PRL): 30,969 ng/mL) and autonomous growth hormone (GH) hypersecretion. Histopathology confirmed a sparsely granulated lactotroph tumour with extensive amyloid spherules and dystrophic calcifications (Ki-67: 8%). Notably, immunohistochemistry demonstrated PRL positivity without GH immunoreactivity, suggesting tumour heterogeneity with sampling limitations. Comprehensive systemic amyloidosis screening, the first systematic evaluation reported for this entity, excluded systemic disease. Following surgical debulking with extensive residual disease, postoperative cabergoline treatment resulted in a reduction in the PRL (4,700→927 ng/mL). Given the presence of amyloid-associated dopamine resistance, cabergoline was discontinued, and radiotherapy (RT) (45 Gy) was initiated to control the amyloid burden, followed by temozolomide. Based on evidence from other malignancies suggesting RT-mediated amyloid reduction, cabergoline was reintroduced postradiotherapy without paradoxical tumour growth. Concurrent cabergoline-temozolomide therapy, a novel approach that differs from conventional sequential protocols, achieved a dramatic response: 93.4% prolactin reduction (10,320→677 ng/mL) and 52.4% tumour volume reduction. This superior outcome far exceeded that of initial postsurgical cabergoline monotherapy (80% reduction), suggesting that RT successfully modulated the amyloid burden and restored dopamine sensitivity. This case suggests that RT may restore dopamine agonist sensitivity in patients with amyloid-containing prolactinomas, potentially enabling concurrent dopamine agonist-temozolomide therapy in refractory cases, warranting further validation.

16 December 2024 in Hormones
Verified
Journal Article
Closed access
PDF file
BEBuruc Erkan
Buruc Erkan
MCMehmet Said Cil
Mehmet Said Cil
MCMehmet Cingoz
Mehmet Cingoz
SBSebnem Burhan
Sebnem Burhan
SASeyma Aksoy
Seyma Aksoy
EHEsra HATIPOGLU
Esra HATIPOGLU

26 February 2026 in Neuroendocrinology
Verified
Journal Article
Closed access
SCSanem Cil
Sanem Cil
APAslihan Pekmezci
Aslihan Pekmezci
HKHüseyin Karatay
Hüseyin Karatay
FDFatih Mert Dogukan
Fatih Mert Dogukan
SBSebnem Burhan
Sebnem Burhan
EHEsra HATIPOGLU
Esra HATIPOGLU
Background: Calcitonin gene-related peptide (CGRP) is a potent vasodilatory neuropeptide involved in inflammation, vascular regulation, and pain mechanisms with potential relevance to endocrine and neurological processes. Furthermore, it exerts specific effects on the tumor microenvironment in certain malignancies. The contribution of CGRP to pituitary adenogenesis has yet to be elucidated. This study aimed to investigate CGRP expression by immunohistochemistry in patients with acromegaly and nonfunctioning pituitary adenomas (NFPAs) and its associations with tumor features, symptoms, and treatment response. Methods: This study included tissue samples obtained from 49 patients who were followed and underwent transsphenoidal surgery at our center: 30 with acromegaly and 19 with NFPAs. Tumor samples were evaluated for CGRP using a polyclonal anti-CGRP antibody (GeneTex, 1:200). Clinical, radiological, and surgical data were collected. Histopathology included hormone staining, estrogen receptor, granularity, transcription factors, Ki-67, and mitotic count. Results: CGRP positivity was observed in 50% of acromegaly patients and in none of the NFPA group (p < 0.001). CGRP expression was not significantly associated with tumor size, invasion, need for surgery, residual tumor, treatment resistance, or granularity. In acromegaly cases with CGRP-positive adenomas, chronic headache tended to be more common (40% vs. 13%, p = 0.09), and postoperative headache resolution rate was lower (33.3% vs. 80%, p = 0.07). The postoperative remission rate tended to be lower (60% vs. 86.7%, p = 0.09). Conclusion: CGRP was found to be notably present in somatotropin-producing adenoma tissues, yet it was entirely absent from nonfunctioning adenoma tissues. The detection of CGRP within adenoma tissue could correlate with an increased incidence of persistent headaches and diminished postoperative remission probabilities in acromegaly.

7 November 2025 in Advanced Neurology
Verified
Journal Article
Open access
PDF file
SDSuat Demir
Suat Demir
BEBuruc Erkan
Buruc Erkan
EAEbubekir AKPINAR
Ebubekir AKPINAR
LPLutfi Sinasi Postalci
Lutfi Sinasi Postalci
Cerebral vasospasm (CV) following spontaneous subarachnoid hemorrhage is a serious complication that can lead to delayed cerebral ischemia, significantly increasing both morbidity and mortality. This article offers an in-depth examination of the pathophysiological mechanisms, risk factors, diagnostic strategies, and currently available treatment options concerning CV. Several distinct yet interconnected processes contribute to the development of vasospasm, such as oxidative stress driven by oxyhemoglobin, increased endothelin-1 activity, diminished nitric oxide availability, endothelial dysfunction, vascular inflammation, and sympathetic overactivation. In symptomatic cases, digital subtraction angiography remains the most reliable modality for diagnosis, offering detailed vascular visualization and the opportunity for concurrent therapeutic intervention. Among pharmacological agents, oral nimodipine is the only drug with proven efficacy in enhancing functional outcomes and is strongly endorsed by current clinical guidelines (Class I, Level A). In cases of refractory vasospasm, endovascular treatments such as transluminal balloon angioplasty and intra-arterial vasodilator infusion play a critical role. The management of CV requires an individualized, time-sensitive, and multimodal approach in both diagnosis and therapy. There remains a need for advanced randomized controlled trials and standardized treatment protocols in this field.