Investigation of the Effectiveness of an Algorithm as an Auxiliary Method in Intraoperative Consultations of Central Nervous System Tumors.

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.

Evaluation of the therapeutic effects of arbutin on cisplatin-induced ovarian toxicity in rats through endoplasmic reticulum stress and Nrf2 pathway.

Arbutin (ARB) is a glycosylated hydroquinone with potent antioxidant effects. Although cisplatin (CP) is widely used in chemotherapy, its toxicity in healthy tissues, including ovotoxicity, is an insurmountable problem. This study aimed to evaluate the therapeutic effect of ARB against CP-related ovototoxicity by including nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in rats for the first time. Rats treated one dose of CP (5 mg/kg) on the first day, followed by ARB (5 and 10 mg/kg) for three days. Serum reproductive hormone levels were determined using ELISA kits. Oxidative stress (OS), inflammation, endoplasmic reticulum stress (ERS) and apoptosis markers in ovarian tissue were also determined colorimetrically. In addition, how CP affects Nrf2 pathway and the effect of ARB on this situation were also addressed. ARB treatment reduced the levels of markers of OS, inflammation, ERS and apoptosis in ovarian tissue of CP-stimulated animals. ARB regenerated the depleted antioxidant system by triggering Nrf2 pathway in the ovarian tissues of animals stimulated by CP. Histological findings also supported the therapeutic efficacy of ARB. The results indicate that ARB may have therapeutic effects against CP-induced reproductive toxicity with its Nrf2 activator potential. ARB should be tested in more extensive studies as a new generation chemopreventive candidate molecule.

PD-L1 expression in invasive solid papillary breast carcinomas.

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.

Granular cell tumor in a child: A rare case report.

A granular cell tumor (GCT) is a rare, usually benign soft tissue neoplasm that is commonly seen in the head and neck region. It is derived from the Schwann cells of the peripheral nerves. GCT is uncommon in children. 6-year-old girl was referred to our hospital for swelling over her left scapula, and a surgical excision was performed to remove the mass. Microscopically, the tumor was composed of cells with large granular cytoplasm and small oval to round nuclei. These cells stained positively for the following proteins: S-100, CD68, neuron-specific enolase, calretinin, and inhibin A. A GCT is usually benign, with a good prognosis, and less than 2% of the cases are reported to be malignant. It is worth noting that such tumors may arise in atypical locations and there is a possibility of malignancy.

Xanthomatous Meningioma: A Case Report.

Meningioma is a neoplasm derived from meningothelial cells. Grade1 meningiomas consist of 9 different subtypes. One of the rare subtypes is metaplastic meningioma. Metaplastic meningioma could be defined as "xanthomatous meningioma" in the presence of prevalent xanthomatous changes. A 32-year-old male patient presented to the outpatient clinic with complaints of vertigo and tinnitus. Magnetic resonance imaging revealed a large mass lesion of 7.4 cm in the right frontal region with an extra-axial localization. Resection material demonstrated a neoplasm composed of classical meningothelial meningioma areas accompanied with areas of xanthomatous changes, containing cells with clear, vacuolated cytoplasm. Epithelial membrane antigen (EMA), vimentin, and progesterone expression were evident in both xanthomatous and meningothelial meningioma areas. Additionally, CD68 positivity was also observed in xanthomatous areas. EMA positivity is a neoplastic marker for xanthomatous cells and is a critical marker to differentiate these cells from macrophages, which is crucial for pathologists in the differential diagnosis. Xanthomatous meningiomas are quite rare and our case presentation is the 7 < sup > th < /sup > one in the current literature.