Aims: The 2016 WHO Classification of Tumors of the Central Nervous System introduced a paradigm shift by integrating molecular features with traditional histomorphology. This study aims to retrospectively re-evaluate glial tumor cases from a major tertiary center in light of these evolving classification criteria and provide a baseline for future molecular research. Methods: A retrospective analysis was conducted on 395 glial tumor cases diagnosed at the Karadeniz Technical University Faculty of Medicine, Department of Pathology, between 2005 and 2016. The cases were re-grouped according to the 2016 WHO criteria. Due to the lack of molecular data available during the archival period, cases were categorized under the “Not Otherwise Specified” (NOS) group to establish a comprehensive database. Results: Among the 395 cases analyzed, glioblastoma was identified as the most frequent histological subtype (n=235). A male predominance was observed (56.5%), with mean and median ages of 48.21 and 50 years, respectively. The most common anatomical location was the frontal lobe, and Histological Grade IV was the most prevalent grade. Statistical analyses indicated that demographic and distribution data were consistent with global literature. Conclusion: The findings align with international demographic trends while highlighting the practical challenges of transitioning to molecular-based classifications. While the subsequent 2021 WHO Classification further emphasizes IDH status, "histologically defined" or "NOS" designations remain crucial for regions where molecular testing infrastructure is limited. This study provides a robust archival baseline that facilitates future molecular studies and serves as a reference for glial tumor characterization in resource-constrained settings.

OBJECTIVE:One of the most difficult areas in a surgical pathology practice is intraoperative consultation. In a previous study, we proposed an algorithm that provides a systematic approach to intraoperative consultation for central nervous system tumors. Our aim was to demonstrate the effectiveness of this algorithm. MATERIAL AND METHODS:102 cases were selected from intraoperative consultation procedures performed at our institution between 2012 and 2020. The algorithm was tested by five observers. The observers examined the smears and frozen sections without the algorithm, and then with the algorithm. RESULTS:The percentage change in the rate of correct diagnoses made by the four observers (O) increased after using the algorithm (O2: 8%, O3: 5%, O4: 8% and O5: 13%), but decreased for only one observer (O1) (5%). The most common error made by the four observers was `grading of glial tumors` (O1: 40%; O2: 23%; O4: 40% and O5: 27.5%), and this group of errors was mostly corrected by using the algorithm (O1: 33%; O2: 3.8%; O4: 23% and O5: 10%). For two observers (O2 and O5), a statistically significant change in diagnostic levels was observed after using the algorithm (p=0.024 and p=0.040; respectively). In addition, thanks to the use of the algorithm, a high degree of agreement was found between the observers` diagnoses (77.7%, p < 0.001). CONCLUSION:In the intraoperative consultation of central nervous system lesions, algorithms can help to increase the accuracy of the diagnosis and reduce interobserver variability. This study demonstrates that an algorithmic approach is an effective method for pathologists in intraoperative consultation procedures.

Pilocytic astrocytoma (PA) is the most common glial tumors of childhood. It can also be seen in young adults. It is typically localized in the cerebellum and is a WHO grade 1 tumor. It is rarely seen in the cerebral hemisphere and spinal cord. Calcification is unusual feature for PA. Angiocentric arrangement or pseudorosette structures are also unusual morphologic patterns observed in PA, and few cases have been reported in the literature. Prognosis is usually good. The prognosis tends to be slightly worse in supratentorial PAs. In here the differential diagnosis between PAs with diffuse angiocentric arrangement and calcification and tumors with angiocentric arrangement or perivascular pseudorosette such as ‘‘pilomyxoid astrocytoma, angiocentric glioma, papillary glioneuronal tumor, astroblastoma” is discussed.

Purpose: Most meningiomas can be treated by surgical resection. However, depending on the location of the lesion, incomplete resection or high-grade meningiomas may have a poor prognosis. The new methods such as immunotherapy may improve our options for effective, patient-specific treatment of meningiomas. We aim to contribute to the development of new personalized treatment strategies by investigating the status of Gal-9 in meningiomas. Materials and Methods: Four hundred two cases diagnosed in our laboratory between 2007 and 2020 were used for the study. New blocks of multiple tissues were prepared for immunohistochemistry using the tissue microarray method. Immunohistochemical staining of Gal-9 antibody was evaluated using the H-score method. Results: Of the 402 cases studied, 289 were female and 113 were male. Two hundred and seventy-one (67.4%) cases were WHO grade 1; 121 (30.1%) were grade 2 and 10 (2.5%) were grade 3. A high H-score was observed in grade 1 and 2 tumors (H-score: 93.38 and 93.91) and a low H-score in grade 3 tumors (H-score: 59.40). There was no significant correlation between brain invasion and Gal-9 expression. No significant correlation was found between Gal-9 expression and minor criteria used in tumor grading. Conclusion: A statistically significant difference was found between Gal-9 H-score and tumor grade. Gal-9 had a lower H-score in high-grade meningiomas and its expression level decreased. Therefore, Gal-9 with different expression levels can be used as a prognostic and predictive biomarker as well as an important molecule for treatment.

Background/aim:Meningiomas are the most common primary brain tumors of the central nervous system. Immunotherapy is a promising treatment method applied in many types of cancer. There is no standard and effective medical treatment to reduce recurrence and mortality in cases of incomplete resection of meningiomas and in high-grade cases. In order to investigate medical treatments in addition to surgery and radiotherapy, in this study, the status of immune checkpoint molecules (PD-L1/PD-1), which are the target of immunotherapy, in meningiomas was investigated. Materials and methods:Four hundred two cases of meningioma diagnosed between 2007 and 2020 at our institution were used. New blocks were prepared from the appropriate blocks of the cases using the tissue microarray method. Sections obtained from these blocks were immunohistochemically stained with PD-1 and PD-L1 antibodies. Obtained data were interpreted with statistical analysis. Results:Expression of PD-L1 was observed in 28.4% of meningiomas. Staining rates are higher in high-grade tumors. The staining rate of PD-L1 in the tumor increased significantly with pattern loss. PD-L1 expression in immune cells is 19.9%. Immune cell expression and the number of expressing immune cells correlate with spontaneous necrosis. Immune cell expression and the number of expressing immune cells are increased in high-grade meningiomas. PD-1 expression in immune cells is 9.0%, and this correlates with brain invasion. Conclusions:With these data, it was observed that the expression of immune checkpoint molecules PD-L1 and PD-1 increased especially in high-grade meningiomas. It may be the subject of research that these molecules may be targets of immunotherapy in the treatment of meningiomas.

Synchytrium endobioticum (Schilb.) Perc. is a chytrid fungus causing potato wart disease and is one of the most important quarantine diseases on cultivated potato. Infected host tissues develop warts rendering the crop unmarketable. Resting spores, that can remain viable and infectious for decades, are formed in warted tissues and are released into the surrounding soil when host tissue decays. To better understand the pathogen’s diversity and to potentially uncover pathways of migrations and introduction events, molecular characterization was performed on the historical S. endobioticum resting spore collection of the Dutch National Plant Protection Organization. Mitochondrial genomes were assembled and annotated, and four novel structural variants were identified from these materials with intronic presence-absence variation in cox1 or cob genes and structural variation in the dpoB – TIR region. Several fungal isolates were shown to contain mixtures of structural variants. We analyzed the mitogenomic sequences obtained from recent potato wart disease findings in Canada and the Netherlands in the context of the historical materials and found that fungal isolates from the new Dutch outbreak contained a specific mixture of mitogenomic variants previously not observed in the Netherlands. Based on the mitogenomic profile, pathotype 38(Nevşehir) was suspected which was later verified with the Spieckermann bioassay. To further facilitate dissemination of data and interactive visual analytics we created a public Nextstrain webpage with S. endobioticum mitogenomic sequences and associated metadata on their geographic origin, pathotype identity and (mixture) of mitogenomic variants ( https://nextstrain.nrcnvwa.nl/Sendo ).

Neoplasms in sinonasal cavity are dominated by epithelial type. Sinonasal osteomas are common, benign, slow-growing, often asymptomatic neoplasms occurring mainly in the frontal and ethmoid sinuses. Peripheral nevre sheath tumors are soft tissue neoplasms rarely encountered in the sinonasal region. Schwannoma is a benign peripheral nevre sheath tumor. Here, we presented co-occurence of osteoma and schwannoma. So far, osteoma infiltrated by schwannoma in sinonasal region is not reported in English literature. Additionally it was masquerading as malignant tumor radiologically. The pathologist should be aware of a second soft-tissue tumor that may accompanied the radiologically suspicious malignant bone lesions.

Erdheim–Chester Disease (ECD) is a rare non-Langerhans form of systemic histiocytosis of unknown etiology with multiple organ involvement. It most commonly affects the long bones, lungs, heart, retroperitoneum, eyes, and kidneys and less commonly the brain and spinal cord. Although there are very few cases of supratentorial ECD mimicking intracranial meningioma reported in literature, to the best of our knowledge, there are no reports on ECD mimicking infratentorial pontocerebellar angle meningioma. The present study reports a case of ECD mimicking pontocerebellar angle meningioma. This study aimed to emphasize the importance of systemic evaluation using a multidisciplinary approach as well as the need for considering ECD as a differential diagnosis of xanthomatous meningioma.

Background: Invasive solid papillary carcinomas (ISPC) are rare malignant neoplasms in the classification of WHO 2019 breast tumors. Aims: We aimed to investigate the correlations between programmed cell death ligand-1 (PD-L1) expression status of tumor and immune cells and clinicopathological parameters by molecular classification of this rare morphological subtype. This study will contribute to the literature about the PD-L1 expression state of ISPCs for the first time. Material and Methods: The study included 19 invasive solid papillary carcinoma cases diagnosed between 2009 and 2019 in Pathology Department. Molecular subtyping was performed in 19 cases by immunohistochemical studies (ER/PR, Her-2/neu, Ki-67), and PD-L1 expression was evaluated in neoplastic and immune cells. Results: PD-L1 expression was detected in 4 (21%) cases, 3 (75%) of them were in luminal B and 1 (25%) were in the luminal A group. The correlation between molecular subtypes and PD-L1 expression was statistically significant (P = 0.016). Patients with PD-L1 expression had a higher Ki-67 index than patients without PD-L1 expression (P = 0.037). In addition, there was a statistically significant correlation between PD-L1 expressions of intratumoral lymphocytes and PD-L1 expressions of neoplastic cells (P = 0.004). Conclusions: While predicting the group that will benefit more from immunotherapy in solid papillary carcinoma cases, not only PD-L1 expression of tumor cells but also PD-L1 expression in tumor infiltrating lymphocyte (TIL) can help. In addition, PD-L1 staining rates of tumor cells as well as clinicopathological parameters (molecular subtype, high Ki-67 index, presence of TIL) can be predictive about immunotherapy.

OBJECTIVE To investigate factors that may affect prognosis in gastrointestinal stromal tumors (GISTs). STUDY DESIGN A descriptive study. PLACE AND DURATION OF STUDY Karadeniz Technical University Hospital, Trabzon, Turkey from 2000 to 2019. METHODOLOGY All the patients diagnosed with GIST and followed-up in this centre were included. Those who were not followed-up in this centre were excluded. The Chi-square test for differences between variables in independent groups; and the Kaplan-Meier method for survival rates were used. RESULTS Median tumor size was larger in patients with recurrence, compared to those without (8cm vs. 5 cm, p <0.001). Recurrence rates were higher with mitosis ≥5 in 50 high-power-fields than with low mitosis (52.6% vs. 23.4%, p = 0.021). Median Ki-67 percentages were higher in patients with recurrence than without (5 vs. 2, p = 0.031). Recurrence rates were higher with necrosis and bleeding than without (57.7% vs. 14.3%, p = <0.001; 50% vs. 13.8%, p = 0.003). Median overall-survival (OS) was shorter in with mitotic counts ≥5 compared to <5 (52.0 vs. 110.0 months, p = 0.051) and with ulceration than without (36.0 vs. 110.0 months, p = 0.017). The groups below (<43.5) and above (>43.5) the median prognostic-nutritional-index (PNI) value were similar in terms of OS and disease-free survival (DFS) (52 vs. 70 months, p = 0.174; 82 vs. 100 months, p = 0.411). Median DFS was shorter with ulceration than without (27 vs. 100 months, p = 0.048). CONCLUSION While necrosis, bleeding, ulceration, mitosis, size, and Ki-67 significantly affect the prognosis in GIST, PNI has no significant effect. Key Words: Gastrointestinal stromal tumors (GIST), Survival, Prognosis, Recurrence, Prognostic Nutrition Index (PNI).

Objective: To date, numerous molecular tests have been developed for preoperative evaluation of thyroid nodules. Nevertheless, these tests cannot be administered in many centers due to their imprecise diagnoses and high costs. The present study aimed to investigate the effect of making surgical decisions in a panel through a multidisciplinary approach after clinical, ultrasonographic, and pathological evaluation of nodules on the accuracy of the decisions. Methods: The retrospective study included patients with thyroid nodules who underwent preoperative ultrasonography followed by fine-needle aspiration biopsy, which was confirmed by postoperative pathological examinations between January 2017 and January 2019. The relationship between ultrasonography features of nodules and malignancy was analyzed. A comparison was performed between patients who were referred for surgery through the multidisciplinary versus non-multidisciplinary approach. Results: A total of 255 nodules in 211 patients were evaluated in the study. The prevalence of malignancy was 100% in nodules with hypoechogenicity + microcalcification + margin irregularity (P <.001). The likelihood of malignancy was significantly higher in dual combinations of these 3 adverse conditions (P <.001 for all). Margin irregularity was found to be the most predictive model for malignancy (CI: 1.9-13.8, odds ratio: 5.249, P <.001). The multidisciplinary approach was superior to the non-multidisciplinary approach in the detection of malignancy (P =.008). Conclusion: Margin irregularity had the highest predictive value for the detection of malignancy. Employing the multidisciplinary approach in preoperative evaluation of thyroid nodules can be highly effective in detecting malignancy and preventing unnecessary surgery.

Background: Colorectal cancer (CRC) is the third most commonly occurring cancer in men and the second most common cancer in women. Despite advances in surgical techniques and chemotherapeutic regimens, CRC continues to be one of the main causes of cancer-related deaths in the world. Aims: The aim of the study was to evaluate the immunohistochemical expression of human epidermal growth factor receptor 2 (HER2) and the relationship between HER2, clinicopathological parameters, and microsatellite instability (MSI). Materials and Methods: Two hundred and forty resected CRCs at our institution between 2016 and 2019 were included in the study. Tumors were re-evaluated and classified according to the World Health Organization. Tissue macroarray techniques were used to generate tissue samples. HER2 antibody was performed using the automated system. Results: HER2 antibody was score 3 positive in only 5 cases. Score 2 was observed in 13 cases, score 1 in 27, score 0 in 195. All of the HER2-positive cases were metastatic. All of them were tubular adenocarcinoma. HER2 positive cases were well and moderately differentiated. Four of the HER2 positive cases were T3 stage, and one was T4. Conclusion: A total of 2.1% of CRCs were positive for HER2 antibody. There was a positive correlation between HER2 and distant metastasis. There was no significant relationship between MSI, other prognostic parameters, and HER2.

Fungal pathogens cause significant losses both in terms of quality and quantity on oregano (Origanum spp.) cultivation. Various fungal diseases on oregano grown in experimental plots of Ankara Field Crops Research Institute were observed in the years 2018–2020. A lot of symptoms; including dark brown necrosis, brown discoloration in the xylem vessels, brown spots and necrosis on the stems, splitting on the stem and branches together with brown, leaf spots and blights at varying sizes were observed. In addition, brown rust symptoms were also found. The fungal pathogens were isolated by plating disease samples taken from the peripheries of the necrosis or spots on culture media of water agar, potato dextrose agar and malt extract agar. The obtained fungi were identified by their morphological characteristics first, at least at genus rank and then by generating ITS1 and ITS4 gene sequences and comparing the sequences by the ones deposited in GeneBank. The most common and widespread pathogen was Boeremia exgua var. exigua and it was isolated from disease symptoms on branches, stems, collars and leaves from all the Oregano genotypes. From the brown necrotic areas at the collar, mostly Fusarium equiseti was isolated. From the leaf spots, along with Boeremia exgua var. exigua, Alternaria alternata complex and A. tenuissima were also recovered. The rust pathogen Puccinia menthae was determined on only Origanum vulgare var. gracile. Alternaria alternata complex, A. tenuissima, Fusarium equiseti, Boeremia exgua var. exigua were first records on Origanum spp. and Puccinia menthae on Origanum vulgare var. gracile in Turkey.

Meningiomas are the most common primary intracranial tumor thought to derived from arachnoidal cap cells in the meningeal coverings of the spinal cord and brain. The current WHO classification, published in 2016, includes nine different subtypes of grade 1 meningiomas, three different subtypes of grade 2 meningiomas, and three different subtypes of grade 3 meningiomas. Metaplastic meningioma is a rare variant which shows focal or diffuse mesenchymal tissue component. Xanthomatous meningioma which has foamy cell changes is a quite rare variant of metaplastic meningioma. Two patients, 54 and 59 years old, who applied to our clinic with similar symptoms, were operated for meningioma. Histopathological examination of their biopsy showed that neoplastic cells had oval-round nuclei and eosinophilic cytoplasm. In xanthomatous meningioma, some neoplastic cells had clear vacuolated cytoplasm (foamy cells). In microscopic examination of resection material in one of these patients, cells in some areas of the tumor had clear vacuolated cytoplasm (foamy cells). These neoplastic cells were scattered among other meningothelial cells and they were positive for EMA. To the best of our knowledge, until today there have been only 14 reported xanthomatous meningioma cases in English literature. Here, we aimed to discuss the pathogenesis and differential diagnosis of xanthomatous meningioma in two different cases.

In rectal carcinomas, the rate of pelvic recurrence is quite high with surgery and adjuvant chemoradiotherapy (CRT). Therefore, neoadjuvant chemoradiotherapy (CRT) is used increasingly in rectal cancers. In our study, we aimed to reveal the CRT response in rectal cancers and to determine which clinical-morphological prognostic parameters are effective in predicting the treatment response. Forty-six patients with rectal cancer diagnosed between 2016-2019 and treated with neoadjuvant CRT were included in the study. The cases were re-examined by two pathologists for prognostic parameters and tumor regression grade (TRG). Modified Ryan Scoring system was used to evaluate TRG. Data showing Microsatellite instability (MSI) status with some parameters such as tumor diameter and distant metastasis before treatment were obtained by searching patient files on the computer. Nineteen of the 46 cases were female and 27 were male. Forty-four of the cases are classical adenocarcinoma and 2 of them are mucinous adenocarcinoma. According to TRG, which was used to evaluate the treatment response, 1 (2.2%) of the cases showed complete response (Score 0); 8 (17.4%) showed near-complete response (Score 1); 18 (39.1%) showed partial response (Score 2) and 19 (41.3%) showed no response or poor response (Score 3). A statistically significant relationship was found among prognostic parameters only between tumor grade and treatment response (p = 0.021). Response to treatment after CRT is in the inverse ratio to the pathological grade of the tumor. The treatment response is better in low grade tumors. In patients with rectal cancer and treated with neoadjuvant CRT, survival is determined not by the pre-treatment clinical staging, but rather by the pathological staging, which includes TRG after treatment. Tumor response to CRT is also effective in planning adjuvant chemotherapy in patients with rectal cancer.

Objective:Lightning is a major reason for weather-related deaths and injuries. The risk of being struck by lightning is higher for those who work outdoors.Methods:In this retrospective study, 19 lightning-related deaths between 2007 and 2017, which were obtained from the archives of Council of Forensic Medicine Trabzon Group Chairmanship, were evaluated.Results:The age range of the cases was between 8 and 75 years and 15 of them were male. Nine of the cases were a shepherd. The number of the cases went to the top in June with nine cases and 17 of the decedents were found in outdoor spaces. On the external examinations of eight cases (42%), there was a Lichtenberg figure. The electrical entrance regions were the head and neck in 10 cases (53%). Bleeding, contusions and lacerations, especially in the lungs and brain, were considered to be due to the blast effect of the lightning. Subepidermal/suprabasal dissociation, spindle appearance in epithelial cells of epidermis and dermal appendages, intraepidermal vesicles and collagen denaturation were detected in microscopic examinations.Conclusion:Lightning is an airborne event that may cause death in outdoor environments. After a lightning strike, a Lichtenberg figure can be seen on external examination, and macroscopic bleeding in the lungs and brain can be observed on internal examination. It will be beneficial to provide basic awareness training on lightning strike risks for the whole society, especially for shepherds and agricultural workers, to reduce the deaths due to lightning strikes, the exact death causes of which can be determined through autopsies.

Background/aim: Microsatellite instability tests and programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) in the immune checkpoint pathway are the tests that determine who will benefit from immune checkpoint inhibitor therapy. We aimed to show the expression of DNA mismatch repair proteins and PD-1/PD-L1 molecules that inhibit immune checkpoints, to explain the relationship between them, and to demonstrate their predictive role in recurrent and nonrecurrent glioblastoma. Materials and methods: We analyzed 27 recurrent and 47 nonrecurrent cases at our archive. We performed immunohistochemical analysis to determine expressions of PD-1, PD-L1, and mismatch repair proteins in glioblastoma. We evaluated the relationship between these two group and compared the results with the clinicopathological features. Results: The mean age of diagnosis was significantly lower in recurrent glioblastoma patients. Median survival was longer in this group. We found that PD-L1 expression was reduced in recurrent cases. Additionally, recurrent cases had a significantly higher rate of microsatellite instability. Loss of PMS2 was high in both group but was substantially higher in recurrent cases. Conclusion: The presence of microsatellite instability and low PD-L1 levels, which are among the causes of treatment resistance in glioblastoma, were found to be compatible with the literature in our study, with higher rates in recurrent cases. In recurrent cases with higher mutations and where immunotherapy resistance is expected less, low PD-L1 levels thought that different combinations with other immune checkpoint inhibitors can be tried as predictive and prognostic marker in GBM patients.

Potato pink rot, caused by Phytophthora erythroseptica , occurs in many potato growing countries having cool and humid climates, sometimes producing high rates of crop loss. Recently, a new Phytophthora species has been isolated from potato tubers grown in a 5 ha field for certified seed and showing pink rot symptoms by using a Phytophthora selective medium. The pathogen was obtained from potato variety Everest which is an early variety for the traditional markets in the Mediterranean area and the Middle East and moderately susceptible to late blight. This species was identified as P. erythroseptica by using morphological and physiological characteristics and also analysing ITS, Cox and β-tubulin gene sequences, and differs from another species, P. cryptogea which was also found causing pink rot on potato.

Introduction Bronchogenic cysts (BC) are rare congenital cystic lesions formed during the migration of embryonic primitive foregut buds during early embryogenesis (1). They are usually found in the posterior mediastinum, but they may rarely be found in adrenal glands (2). Morphologically, they have the same characteristics as the tracheobronchial system. Most BC are asymptomatic in the early stages, but they can become symptomatic because of pressure caused by the cyst in the surrounding area. Additionally, BC can cause bleeding, rupture or infections (3). Malignant transformation is very rare, with only 0.7% risk (4). A case study, in which a bronchogenic cyst was located in the adrenal area, was presented to us. Bronchogenic cysts are rare congenital cystic lesion formed during the migration of embryonic primitive foregut buds during early embryogenesis. Although they are most commonly located in the mediastinum, in some rare cases, they are found localized in the periadrenal area. In our male patient in 22 year old who had no symptomps, a multiloculated bronchogenic cyst was detected incidentally in the periadrenal area. The lesion was located in the left adrenal area as observed using imaging techniques. The large mass was extracted by laparoscopy to confirm the diagnosis. Histopathological examination described the cyst as multilocular and bronchogenic. The case was presented to us because of the rare occurrence of bronchogenic cysts in the periadrenal area, and an accompanying ectopic kidney condition.