Reliability assessment of methylthioadenosine phosphorylase immunohistochemistry as a surrogate biomarker for CDKN2A homozygous deletion in adult-type IDH-mutant diffuse gliomas.

According to the 2021 World Health Organization classification of brain tumors, astrocytomas containing a CDKN2A/B homozygous deletion (HD) are designated as grade 4 even when no microvascular proliferation and/or necrosis is present. In this study, we aimed to investigate the relationship between CDKN2A HD and loss of methylthioadenosine phosphorylase (MTAP) expression in adult-type IDH-mutant gliomas and to assess the sensitivity and specificity of MTAP immunohistochemistry (IHC) along with interobserver agreement as a surrogate biomarker for CDKN2A HD. Eighty-eight astrocytomas and 71 oligodendrogliomas cases that were diagnosed between 2014 and 2021 at Hacettepe University were selected and tissue microarrays were conducted to perform CDKN2A fluorescence in situ hybridization and MTAP IHC. Twenty-five (15.7%) cases harbored CDKN2A HD. MTAP loss was detected in 28 (15.7%) cases by the first observer and 27 (17%) cases by the second observer. The sensitivity and specificity of MTAP were calculated as 88% and 95.52%-96.27% for 2 observers. A very good/perfect agreement was noted between the observers (Cohen kappa coefficient = 0.938). Intratumoral heterogeneity was observed in 4 cases. MTAP IHC was found to be a reliable surrogate biomarker as a possible alternative to CDKN2A HD identification with a high sensitivity and specificity along with high interobserver agreement.

Black Henna Deposits Masquerading a Melanoma of the Plica Semilunaris.

PURPOSE: The aim of this study was to describe a rare case of conjunctival black henna accumulation that was clinically misdiagnosed as melanoma. METHODS: This retrospective case report reviewed the clinical findings and histopathologic features of a pigmented plica semilunaris lesion excised from a 63-year-old woman. The patient had a history of regular use of black henna in her childhood. The conjunctival pigmentation was present since her early teenage years but started to grow only recently. RESULTS: There was a darkly pigmented mass mainly covering the plica semilunaris of the right eye with additional irregularly scattered pigmentation in the medial bulbar conjunctiva. Excisional biopsy of the plical tumor revealed nodular pigment deposits with lymphocytic infiltration. There were no neoplastic cells. The specimen stained negative for pan-keratin, CD68, and CD34. Melanin bleaching was also negative. CONCLUSIONS: Long-term exposure to black henna as a hair dye may lead to subconjunctival accumulation and mimic melanoma.

A rare benign tumor of the liver mimicking angiosarcoma: Anastomosing hemangioma.

Anastomosing hemangioma of the liver (AHL) is a very rare condition and limited to a few cases. It is often confused with well-differentiated angiosarcomas and causes overtreatment. In this report, we present a 53-year-old female patient diagnosed with AHL. Since the tumor is rarely seen, it is important to define well the imaging and pathological features for preventing unnecessary surgeries and related morbidities.

IgG4-related pachymeningitis-Long term follow up and outcome of six patients.

OBJECTIVE: Our understanding of IgG4-RD and pachymeningitis has grown substantially, but the optimal approach for diagnosis, management, and long-term outcomes is still an area of uncertainty. METHODS: HUVAC is a database for IgG4-RD patients, this database was retrospectively evaluated for pachymeningeal disease. Demographic, clinical, serological, imaging, histopathological data, and treatment details were re-interpreted in patients with pachymeningitis. RESULTS: Among 97 patients with IgG4-RD, 6 (6.2%) had pachymeningitis. None of these patients had extracranial features, and also, in most of the patients, serum IgG4 levels were normal. Tentorium cerebelli and transverse sinus dura were the most commonly involved in the posterior fossa. During 18 months of median follow-up on steroid+-rituximab, none of them relapsed as pachymeningitis. CONCLUSION: Our patients were mainly older males with sole neurological involvement. Non-specific headache was the most common manifestation, and serum IgG4 levels were not useful for diagnosis. Typical radiology and tentorial thickening should suggest IgG4-RD and prompt an early biopsy. Moreover, accompanying hypophysitis could also be a clue. With steroids+ rituximab treatment, no relapse related to meningeal involvement was seen in long-term follow-up.

Evaluation of HSP-27, BAP1, BRAF V600E, CCR7, and PD-L1 expression in uveal melanoma on enucleated eyes and metastatic liver tumors.

BACKGROUND: The presence of metastatic disease is one of the most important factors limiting survival in patients with uveal melanoma. Studies on proteins associated with metastatic mechanisms are sparse in the literature. METHODS: Enucleation samples from 15 patients with metastatic uveal melanoma (Group 1), liver metastasectomy samples from 8 patients with metastatic uveal melanoma (Group 2), and enucleation samples from 20 patients with non-metastatic uveal melanoma as controls (Group 3) were included in the study. Antibodies against heat shock protein 27 (HSP-27), BRCA1-associated protein-1 (BAP1), C-C chemokine receptor 7 (CCR7), B-Raf proto-oncogene serine/threonine-protein kinase V600E (BRAF V600E), and programmed death-ligand 1 (PD-L1) were used to detect immunoreactivity in each sample by immunohistochemical methods. Correlations between these expressed proteins and selected histopathological and clinical features, and metastatic process were investigated. RESULTS: The frequencies of HSP-27 (median score: Group 1: 8, Group 2: 12, Group 3: 4) and BRAF V600E expressions (number of samples: Group 1: 4 (26.7%), Group 2: 1 (12.5%), Group 3: 0 (0%)), and BAP1 expression loss (number of samples : Group 1: 12 (80%), Group 2: 8 (100%), Group 3: 9 (45%)) were higher in samples from patients with metastatic uveal melanoma (Group 1 + 2) than in those from patients with non-metastatic disease (Group 3) (P = 0.001, P = 0.034, and P = 0.007, respectively). CCR7 expression (median score: Group 1: 0, Group 2: 2, Group 3: 3) was similar among these three groups (P = 0.136). No samples exhibited PD-L1 expression (P = 1.000). One-unit increases in the HSP-27 expression level and BAP1 expression loss were significantly related to 1.375- and 7.855-fold increases in the risk of metastasis, respectively (P = 0.007 and P = 0.017). CONCLUSION: HSP-27 and BAP1 are considered to be associated with metastasis, indicating these proteins as potential treatment targets in metastatic uveal melanoma.

Prognostic significance of pre- and post-treatment PD-L1 expression in patients with primary high-grade non-muscle-invasive bladder cancer treated with BCG immunotherapy.

PURPOSE: Programmed cell death-1 ligand-1 (PD-L1) expression has been associated with prognostic implications in urologic malignancies. We aimed to investigate prognostic significance of pre- and post-treatment PD-L1 expression in patients treated with BCG for high-grade non-muscle-invasive bladder cancer (NMIBC). METHODS: We reviewed a total of 141 high-grade NMIBC cases treated with transurethral resection + ≥ 6 BCG instillations between 2004 and 2017. PD-L1 immunohistochemistry (IHC) scoring was done on 0-3 scale, and cut-off for positive and high-level PD-L1 expression was set to ≥ 1% and ≥ 5% staining of tumor-infiltrating immune cells (IC), respectively. Clinicopathologic characteristics and oncologic outcomes [recurrence-free (RFS) and progression-free survival (PFS)] were compared, stratified by PD-L1 positivity. The prognostic role of PD-L1 was assessed using Kaplan-Meier, and univariate and multivariate Cox regression analyses. RESULTS: Pre-treatment, 46.2% and 6.8% of high-grade NMIBC demonstrated positive and high-level PD-L1 expression, respectively. Positive PD-L1 expression was associated with submucosal invasion and refractory-tumor recurrence. PD-L1 expression was not associated with RFS or PFS in regression analysis. Post-treatment, 55.1% and 11.6% of recurrent tumors demonstrated positive and high-level PD-L1 expression, respectively. Down-regulation of PD-L1 expression was noted in patients with refractory recurrence (p = 0.012). CONCLUSION: Pre-treatment PD-L1 expression was associated with unfavorable pathological features in primary high-grade NMIBC and its expression level after BCG immunotherapy was significantly decreased in patients with refractory recurrence. PD-L1 expression did not have prognostic value for PFS or RFS; therefore, further research is necessary to identify novel biomarkers for prediction of disease outcomes in high-grade NMIBC.

Programmed Death Ligand 1 (PD-L1) Expression in Malignant Mesenchymal Tumors.

OBJECTIVE: Programmed death ligand 1 (PD-L1) found on tumor cells has recently been reported to have a key role in the development and dissemination of many tumors, such as lung and breast carcinomas. In this study, we retrospectively analyzed PD-L1 expression among different types of sarcomas. MATERIAL AND METHOD: Tissue microarrays of 3-4 mm diameter were composed from paraffin blocks of 222 various sarcomas. Slides prepared from microarrays were stained for PD-L1 antibody (Cell Signaling, E1L3N®) using Leica Bond Autostainer. Any membranous staining over 5% of the cells was regarded as positive. Quantitative real-time PCR with TaqMan gene expression assays for PDL1 was performed using whole sections from FFPE tissue of PD-L1 positive cases, by normalizing absolute values to ß-actin. Relative expression level of mRNA of PDL1 was calculated and scored using Log102(threshold cycle of b-actin - threshold cycle of PDL1). RESULTS: Immunohistochemically, PD-L1 expression was present in 34 of 222 (15%) sarcomas. 5/13 (39%) undifferentiated pleomorphic sarcomas, 6/18 (33%) malignant peripheral nerve sheath tumors, 5/16 (31%) dedifferentiated liposarcomas, 4/19 (21%) rhabdomyosarcomas, 2/16 (13%) epithelioid sarcomas, 2/15 (13%) leiomyosarcomas, 3/26 (12%) synovial sarcomas, 1/18 (6%) myxoid liposarcoma, 1/2 (50%) extraskeletal myxoid chondrosarcoma, 1/3 (33%) alveolar soft part sarcoma, 1/3 (33%) parachordoma/myoepithelioma, 1/5 (20%) pleomorphic liposarcoma, 1/7 (14%) angiosarcoma, 1/8 (13%) Ewing sarcoma showed PD-L1 expression. Cases of solitary fibrous tumor/hemangiopericytoma (18), desmoplastic round cell tumor (14), Ewing-like sarcoma (6), epithelioid hemangioendothelioma (5), clear cell sarcoma (4), myxofibrosarcoma (4), low grade fibromyxoid sarcoma (2) were all negative. Tumor-infiltrating hematopoietic cells were positive for PD-L1 in 32 cases (15%) with only 2 cases overlapping with PD-L1 staining in tumoral cells. Sixteen of 34 (47%) immunohistochemically PD-L1 positive cases showed significant but low-level PD-L1 mRNA overexpression. CONCLUSION: We have shown PD-L1 expression in a subset of sarcomas, both at the protein and mRNA level. High-grade pleomorphic sarcomas tend to show more frequent PD-L1 expression. Clinical trials are necessary to further assess the effect of anti PD-L1 drugs on sarcomas showing PD-L1 expression.