Comprehensive genomic profiling of pediatric peritoneal mesothelioma: case report with a literature review.

Malignant peritoneal mesothelioma is an extremely rare and poorly recognized neoplasm in children. A 5-year-old boy presented with a 1-year history of progressive painless abdominal distension. A CT revealed a 19 × 19 × 11 cm3 cystic mass in the right hemiabdomen, without infiltrating the surrounding structures. The tumor was completely removed by surgery. The microscopic and immunohistochemical analyses confirmed peritoneal mesothelioma. Comprehensive genomic profiling revealed no major driving mutations including BAP1, no fusions, but with amplifications of AURKA, AURKC, HLA-1B, ZNF-217, OR5F1 and MEN1 genes. Imaging follow-up 3 months after surgery revealed metastatic disease. The patient died of pneumonia at another hospital shortly after the last follow-up examination at our institution. Pediatric peritoneal mesothelioma is an extremely rare malignancy with limited targeted options and a poor prognosis. Some of the identified molecular genomic biomarkers require further exploration and validation in this cancer.

Lipofibromatosis arising in a right labiocrural fold in a 14-month-old female: a case report study with a 3-year follow-up.

Lipofibromatosis (LF) is a rare benign fibrofatty tumor of infancy and childhood with a predilection for distal extremities, poor margination, and a high local recurrence rate. We report a toddler who presented with an LF involving her right labiocrural fold. Imaging showed a soft tissue mass extending through the right labiocrural fold with possible infiltration into the underlying muscles. The mass was excised entirely, preserving adjacent structures. The histopathologic report revealed the mass to be LF. A 3-year follow-up revealed no disease recurrence. No other cases of LF in this localization have been presented in the literature. Despite its rarity, LF should be considered in diagnosing soft tissue neoplasms in children. Accurate diagnosis and proper surgical management with complete resection are essential to reduce the postoperative recurrence risk.

Genetic variations in AURORA cell cycle kinases are associated with glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most frequent type of primary astrocytomas. We examined the association between single nucleotide polymorphisms (SNPs) in Aurora kinase A (AURKA), Aurora kinase B (AURKB), Aurora kinase C (AURKC) and Polo-like kinase 1 (PLK1) mitotic checkpoint genes and GBM risk by qPCR genotyping. In silico analysis was performed to evaluate effects of polymorphic biological sequences on protein binding motifs. Chi-square and Fisher statistics revealed a significant difference in genotypes frequencies between GBM patients and controls for AURKB rs2289590 variant (p = 0.038). Association with decreased GBM risk was demonstrated for AURKB rs2289590 AC genotype (OR = 0.54; 95% CI = 0.33-0.88; p = 0.015). Furthermore, AURKC rs11084490 CG genotype was associated with lower GBM risk (OR = 0.57; 95% CI = 0.34-0.95; p = 0.031). Bioinformatic analysis of rs2289590 polymorphic region identified additional binding site for the Yin-Yang 1 (YY1) transcription factor in the presence of C allele. Our results indicated that rs2289590 in AURKB and rs11084490 in AURKC were associated with a reduced GBM risk. The present study was performed on a less numerous but ethnically homogeneous population. Hence, future investigations in larger and multiethnic groups are needed to strengthen these results.

The effects of mutational profiles on phenotypic presentation of myeloproliferative neoplasm subtypes in Bosnia: 18 year follow-up.

The identification of mutually exclusive somatic mutations shared among myeloproliferative neoplasm (MPN) subtypes has provided a powerful tool for studying disease evolution. Clinical features, gene mutations, and survival over 18 years were analyzed in MPN patients. One hundred thirty-eight MPN patients were subcategorized according to MPN subtypes: essential thrombocythemia (ET, n = 41), polycythemia vera (PV, n = 56), primary myelofibrosis (PMF, n = 10), and MPN unclassified (MPN-U, n = 31). Patient characteristics included clinical parameters, overall survival (OS), and mutational status of the Janus kinase 2 (JAK2), calreticulin (CALR), and myeloproliferative leukemia virus oncogene (MPL) genes. We compared hematologic and clinical features of JAK2V617F-ET vs. CALR-mutated ET vs. JAK2V617F-PV patients. JAK2V617F-patients had higher values of erythrocytes, hemoglobin, and hematocrit compared to CALR-mutated patients (p < 0.05). The mutant allele burden in JAK2V617F-PV and JAK2V617F-ET patients directly correlated with erythrocyte, hemoglobin, and hematocrit values, but it inversely correlated with platelet count. Thus, mutant allele burden was an indicator of the clinical phenotype in JAK2V617F-MPN patients. OS was not affected by the mutational status. In general, mutated JAK2, CALR, and MPL genes left specific hematological signatures.

Characterization and risk association of polymorphisms in Aurora kinases A, B and C with genetic susceptibility to gastric cancer development.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in genes encoding mitotic kinases could influence development and progression of gastric cancer (GC). METHODS: Case-control study of nine SNPs in mitotic genes was conducted using qPCR. The study included 116 GC patients and 203 controls. In silico analysis was performed to evaluate the effects of polymorphisms on transcription factors binding sites. RESULTS: The AURKA rs1047972 genotypes (CT vs. CC: OR, 1.96; 95% CI, 1.05-3.65; p = 0.033; CC + TT vs. CT: OR, 1.94; 95% CI, 1.04-3.60; p = 0.036) and rs911160 (CC vs. GG: OR, 5.56; 95% CI, 1.24-24.81; p = 0.025; GG + CG vs. CC: OR, 5.26; 95% CI, 1.19-23.22; p = 0.028), were associated with increased GC risk, whereas certain rs8173 genotypes (CG vs. CC: OR, 0.60; 95% CI, 0.36-0.99; p = 0.049; GG vs. CC: OR, 0.38; 95% CI, 0.18-0.79; p = 0.010; CC + CG vs. GG: OR, 0.49; 95% CI, 0.25-0.98; p = 0.043) were protective. Association with increased GC risk was demonstrated for AURKB rs2241909 (GG + AG vs. AA: OR, 1.61; 95% CI, 1.01-2.56; p = 0.041) and rs2289590 (AC vs. AA: OR, 2.41; 95% CI, 1.47-3.98; p = 0.001; CC vs. AA: OR, 6.77; 95% CI, 2.24-20.47; p = 0.001; AA+AC vs. CC: OR, 4.23; 95% CI, 1.44-12.40; p = 0.009). Furthermore, AURKC rs11084490 (GG + CG vs. CC: OR, 1.71; 95% CI, 1.04-2.81; p = 0.033) was associated with increased GC risk. A combined analysis of five SNPs, associated with an increased GC risk, detected polymorphism profiles where all the combinations contribute to the higher GC risk, with an OR increased 1.51-fold for the rs1047972(CT)/rs11084490(CG + GG) to 2.29-fold for the rs1047972(CT)/rs911160(CC) combinations. In silico analysis for rs911160 and rs2289590 demonstrated that different transcription factors preferentially bind to polymorphic sites, indicating that AURKA and AURKB could be regulated differently depending on the presence of particular allele. CONCLUSIONS: Our results revealed that AURKA (rs1047972 and rs911160), AURKB (rs2241909 and rs2289590) and AURKC (rs11084490) are associated with a higher risk of GC susceptibility. Our findings also showed that the combined effect of these SNPs may influence GC risk, thus indicating the significance of assessing multiple polymorphisms, jointly. The study was conducted on a less numerous but ethnically homogeneous Bosnian population, therefore further investigations in larger and multiethnic groups and the assessment of functional impact of the results are needed to strengthen the findings.

Pixel Prostate Software as a Reliable Tool in Depicting Spatial Distribution and Determination of the Prostate Cancer Volume.

INTRODUCTION: Cancer of the prostate (PCa) is the second most common cancer-related cause of death among men and the most common non-cutaneous malignancy in Western countries. Numerous papers have been published on the topic of various aspects of this disease; however, rather little has been written on the diagnostic and prognostic value of the prostate cancer obtained from needle biopsy. AIM: To examine the utility of Pixel Prostate software in determining the volume and topographic distribution cancer of the prostate (PCa), and to analyze it with other variables that are characteristic for PCa. METHODS: retrospectively, 75 patients data and postoperative prostate specimens were analyzed, after determining topographic distribution and cancer volume (PCa), using PixelProstate software. RESULTS: Mean VPCa was 6.99 cm3 (0.14-29.7; median 4.51), and mean percentage cancer volume relative to prostate volume (%VPCa) was 16% (0.1-67.2%; median 13%). 71% of the patients had T2 stage, while the rest had T3 stage. Apex involvement was present in 65% of the patients, while central zone involvement and extraprostatic extension were present in 23.5% and 22.7% of the patients, respectively. Preoperative Gleason score undergrading was present in 27 (36%) patients, while bilateral PCa finding was increased from 51% to 87%, postoperatively. The most discriminant variable according to the prediction of %VPCa>10% had preoperative bilateral needle biopsy findings, with AUC of 0.75 (<.001), with sensitivity and specificity of 84% and 70%, respectively; (+LR 2,8; PPV of 74%; NPV of 82%). %VPCa showed good correlation with prostate specific antigen (PSA) and PSA-density. CONCLUSION: A possibility of precise spatial orientation and volume characterization of the PCa by PixelProstate software was shown. Simultaneously, with time, a clinician, experienced by PP software feedback, gets better insight for the planning of future prostate biopsy, as an important factor in clinical decision making.

Expression of Ki-67 and Estrogen Receptor Beta in Primary Cutaneous Melanoma as a Potential Indicator of Regional Lymph Node Positivity.

In the early stages of cutaneous malignant melanoma (MM), it is extremely difficult to predict adequately the risk from hematogenic and lymphatic metastasis. We investigate whether the immunohistochemical expression of Ki-67 and estrogen receptor beta (ERß) in cells of MM could predict the status of regional lymph nodes. A total of 55 tissue samples of primary cutaneous melanomas with known status of regional lymph nodes were retrospectively evaluated for Ki-67 and ERß expression by quantitative immunohistochemistry and then correlated with the status of regional lymph nodes and relevant clinicopathologic parameters. The ERß-positive expression was detected in 38 of 55 tumors (69.09%). The Clark level showed a strong correlation with ERß expression, as well as pT stage. All cases of MM showed Ki-67-positive expression and an elevated Ki-67 expression was strongly associated with increased Breslow thickness, Clark level, ulceration, lymphovascular invasion, number of mitosis, and pT stage. Logistic regression analysis showed that when ERß levels increase by 1%, the risk of positive lymph nodes decreases by 7% (odds ratio=0.930; 95% confidence interval, 0.87-0.99; P=0.036), and, when the Ki-67 expression increases by 1%, the risk of lymph nodes' positivity increases by 10% (odds ratio=1.108; 95% confidence interval, 1.02-1.19; P=0.009). Correlation between expression of Ki-67 and ERß and the status of lymph nodes has better prognostic significance than the relationship between melanoma thickness and the status of lymph nodes. Our study showed a significant prognostic value of Ki-67 expression in predicting the behavior of MM and the potential prognostic significance of ERß.

Relapsing Tumefactive Demyelination: A Case Report.

OBJECTIVE: We present a case of relapsing tumefactive demyelination in a young female patient, that posed a real diagnostic challenge, with a heterogeneous clinical picture, atypical for multiple sclerosis (MS) presentation, and neuroradiological manifestations with a high suspicion of neoplastic diseases. CASE REPORT: An 18-year old female patient presented to our Neurosurgical Out-patients' Clinic with symptoms atypical for multiple sclerosis, unremarkable neurological deficit, one tumefactive lesion on MRI, followed by relapse and another two lesions within a period of six months. We decided to perform biopsy of the tumefactive lesion with compressive effect. Serological and clinical data were negative for MS, and the patient did not respond well to corticosteroid therapy. Fresh frozen tumor tissue aroused a strong suspicion of gemistocytic astrocytoma, so total resection was done, but the definitive pathohistological examination confirmed tumefactive demyelination. CONCLUSION: For clinicians, it is important to consider demyelinating disease in the differential diagnosis of a tumorlike lesion of the central nervous system, in order to avoid invasive and potentially harmful diagnostic procedures, especially in younger patients.

Apparent diffusion coefficient reproducibility in brain tumors measured on 1.5 and 3 T clinical scanners: A pilot study.

BACKGROUND: Gradient and coil systems, pulse sequence design, and imaging parameters, as well as different scanners, can influence apparent diffusion coefficient (ADC) values. The aim of this study was to evaluate the effect of two different field strengths on the reproducibility of mean absolute ADC measurements in various primary and secondary brain tumors. METHODS: Fifty patients with histologically proven brain tumors were prospectively examined on two MR scanners from the same vendor, with different field strengths-1.5T and 3T-on the same day. Absolute ADC values were compared using the Wilcoxon matched-pairs signed-rank test. Inter-scanner agreement between two different fields in the same tumor was examined using correlation coefficients, and the discrepancy between the highest and the lowest mean absolute ADC values between scanners was tested using a one-way analysis of variance. Statistical significance was set at p < 0.05. RESULTS: There was no statistically significant difference between mean absolute ADC values obtained on 1.5T and 3T scanners for all patients and all brain tumor types. The intratumoral difference in ADC values, averaged from two scanners in the same tumor type, ranged from 1.58 to 4.5% for 1.5T, and from 1.18 to 4.37% for 3T.Inter-scanner agreement was high, and the kappa coefficient ranged from 0.88 to 0.99, with no significant difference between obtained values on different field strengths. CONCLUSION: Based on the results obtained in our study, there is no significant difference between mean absolute ADC values measured in various primary and secondary brain tumors at different field strengths (1.5 and 3.0T MR systems), in the same patient, and in the same tumor, measured on the same day.

PRIMARY EPITHELIOID HEMANGIOENDOTHELIOMA IN THE CEREBELLUM: CASE REPORT WITH REFERENCE TO DRASTIC CHANGE IN THE WHO CLASSIFICATION.

- Epithelioid hemangioendothelioma is a rare vascular brain tumor. It develops from endothelial cells, usually in the liver, lung, bone and soft tissue. Primary localization of this tumor in the intracranial space is very uncommon; only 47 cases have been described in the literature. This tumor was initially classified as grade I (benign) in the World Health Organization (WHO) 2007 classification. In 2016, this tumor was re-classified as grade III (malignant). Herein, the first case report of epithelioid hemangioendothelioma in the cerebellum of a male patient is presented. Complete surgical excision was done. No adjuvant therapy was administered. Magnetic resonance imaging performed 2 years after the surgery continued to show no recurrence of the tumor. To our knowledge, this is the first report of cerebellar location of this rare tumor. In addition, the authors report drastic re-classification of the epithelioid hemangioendothelioma from the benign tumor (WHO 2007) to a malignant one (2016), which significantly changes postoperative management and follow up of this brain neoplasm.

PD-L1 Status in Refractory Lymphomas.

Targeted immunotherapy based on PD-1/PD-L1 suppression has revolutionized the treatment of various solid tumors. A remarkable improvement has also been observed in the treatment of patients with refractory/relapsing classical Hodgkin lymphoma (cHL). We investigated PD-L1 status in a variety of treatment resistant lymphomas. Tumor samples from 78 patients with therapy resistant lymphomas were immunohistochemically (IHC) investigated for the expression of PD-L1 using two antibody clones (SP142 and SP263, Ventana). Thirteen PD-L1+ cases were further analyzed for gene copy number variations (CNV) by NGS and for PD-L1/JAK2/PD-L2 co-amplification using fluorescent in-situ hybridization assay (FISH). PD-L1 positivity (≥5% positive cancer cells, IHC) was present in 32/77 (42%) and 33/71 cases (46%) using SP142 and SP263 antibodies, respectively. Concordance between the two anti-PD-L1 clones was high with only three (4%) discrepant cases. The strongest and consistent (10/11 cases) expression was observed in cHL and primary mediastinal B-cell lymphomas (3/3). Diffuse large B-cell lymphomas (DLBCL) were frequently positive (13/26) irrespective of subtype. Follicular (1/8), peripheral T-cell (3/11) and mantle cell (1/8) lymphomas were rarely positive, while small lymphocytic lymphoma/CLL and marginal zone lymphomas were consistently negative (3/3). Co-amplification/CNVs of PD-L1/JAK2/PD-L2 were observed in 3 cases of DLBCL and cHL, respectively. Of note, all three cHL-amplified cases were positive by FISH, but not by NGS. Since only a fraction of the IHC positive lymphoma cases were positive by FISH and NGS assays, other mechanisms are involved in PD-L1 upregulation, especially in DLBCL. FISH assay may be more suitable than NGS assay for determination of PD-L1 alterations in cHL.

Lung adenocarcinoma mimicking pulmonary fibrosis-a case report.

BACKGROUND: Lung cancer is usually presented with cough, dyspnea, pain and weight loss, which is overlapping with symptoms of other lung diseases such as pulmonary fibrosis. Pulmonary fibrosis shows characteristic reticular and nodular pattern, while lung cancers are mostly presented with infiltrative mass, thick-walled cavitations or a solitary nodule with spiculated borders. If the diagnosis is established based on clinical symptoms and CT findings, it would be a misapprehension. CASE PRESENTATION: We report a case of lung adenocarcinoma whose symptoms as well as clinical images overlapped strongly with pulmonary fibrosis. The patient's non-productive cough, progressive dyspnea, restrictive pattern of pulmonary function test and CT scans (showing reticular interstitial opacities) were all indicative of pulmonary fibrosis. The patient underwent a treatment consisting of corticosteroids and antibiotics, to no avail. Histopathology of the lung showed that the patient suffered from mucinous adenocarcinoma. Albeit the immunohistochemical staining was not consistent with lung adenocarcinoma, tumor's morphological characteristics were consistent, and were used to make the definitive diagnosis. CONCLUSION: Given the fact that radiography cannot always make a clear-cut difference between pulmonary fibrosis and lung adenocarcinomas, and that clinical symptoms often overlap, histological examination should be considered as gold standard for diagnosis of lung adenocarcinoma.

Cystic Renal Oncocytoma and Tubulocystic Renal Cell Carcinoma: Morphologic and Immunohistochemical Comparative Study.

Renal oncocytoma (RO) may present with a tubulocystic growth in 3% to 7% of cases, and in such cases its morphology may significantly overlap with tubulocystic renal cell carcinoma (TCRCC). We compared the morphologic and immunohistochemical characteristics of these tumors, aiming to clarify the differential diagnostic criteria, which facilitate the discrimination of RO from TCRCC. Twenty-four cystic ROs and 15 TCRCCs were selected and analyzed for: architectural growth patterns, stromal features, cytomorphology, ISUP nucleolar grade, necrosis, and mitotic activity. Immunohistochemical panel included various cytokeratins (AE1-AE3, OSCAR, CAM5.2, CK7), vimentin, CD10, CD117, AMACR, CA-IX, antimitochondrial antigen (MIA), EMA, and Ki-67. The presence of at least focal solid growth and islands of tumor cells interspersed with loose stroma, lower ISUP nucleolar grade, absence of necrosis, and absence of mitotic figures were strongly suggestive of a cystic RO. In contrast, the absence of solid and island growth patterns and presence of more compact, fibrous stroma, accompanied by higher ISUP nucleolar grade, focal necrosis, and mitotic figures were all associated with TCRCC. TCRCC marked more frequently for vimentin, CD10, AMACR, and CK7 and had a higher proliferative index by Ki-67 (>15%). CD117 was negative in 14/15 cases. One case was weakly CD117 reactive with cytoplasmic positivity. All cystic RO cases were strongly positive for CD117. The remaining markers (AE1-AE3, CAM5.2, OSCAR, CA-IX, MIA, EMA) were of limited utility. Presence of tumor cell islands and solid growth areas and the type of stroma may be major morphologic criteria in differentiating cystic RO from TCRCC. In difficult cases, or when a limited tissue precludes full morphologic assessment, immunohistochemical pattern of vimentin, CD10, CD117, AMACR, CK7, and Ki-67 could help in establishing the correct diagnosis.

Disseminated histiocytoses biomarkers beyond BRAFV600E: frequent expression of PD-L1.

The histiocytoses are rare tumors characterized by the primary accumulation and tissue infiltration of histiocytes and dendritic cells. Identification of the activating BRAFV600E mutation in Erdheim-Chester disease (ECD) and Langerhans cell histiocytosis (LCH) cases provided the basis for the treatment with BRAF and/or MEK inhibitors, but additional treatment options are needed. Twenty-four cases of neoplastic histiocytic diseases [11 extrapulmonary LCH, 4 ECD, 4 extranodal Rosai-Dorfman disease (RDD), 3 follicular dendritic cell sarcoma (FDCS), 1 histiocytic sarcoma (HS) and 1 blastic plasmacytoid dendritic cell neoplasm (BPDCN)] were analyzed using immunohistochemical and mutational analysis in search of biomarkers for targeted therapy. BRAF V600E mutations were detected in 4/11 LCH and 4/4 ECD cases. A pathogenic PTEN gene mutation and loss of PTEN protein expression were identified in the case of HS. Increased expression of PD-L1 (≥2+/≥5%) was seen in 3/4 ECD, 7/8 LCH, 3/3 FDCS and 1/1 HS, with overall 81% concordance between 2 antibodies used in the study (SP142 vs. MAB1561 clone). These results show for the first time significant expression of the PD-L1 immune checkpoint protein in these disorders, which may provide rationale for addition of immune check-point inhibitors in treatment of disseminated and/or refractory histiocytoses.

Use of Quantitative Fluorescent Polymerase Chain Reaction (QF PCR) in Prenatal Diagnostic of Fetal Aneuploidies in a 17 Month Period in Parallel with Karyotyping.

INTRODUCTION: QF PCR has recently entered diagnostic practice as a possible way to bypass culturing of the fetal cells, as well as to provide a rapid response following amniocentesis. MATERIAL AND METHODS: The effective value of the QF PCR remains a much debated issue, positions ranging from that it makes classic kayotyping obsolete except in special occasions, to that it is no more than a guideline for a mandatory karyotype. Current practices of the gynecology specialists generates samples in such fashion that kariotyping of samples quickly falls behind to the point of obsoleteness, because, by the time a karyotype has been finished, a window of opportunity for termination of pregnancy has closed. RESULTS: QF PCR provides a rapid response alternative, but it is necessary to establish its reproducibility, as well as an algorithm of its use along classic kariotyping. This study contains samples processed in a period from August 1, 2012 to December 31 2013 in both QF PCR and classic karyotype. Object of this study was compare results obtained by two methods, and establish confidence interval of the QF PCR testing. Overall, 661 amniotic fluid samples were processed and typed with QF PCR, out of which 221 were done in parallel with karyiotyping, as an confirmation of results.

Estrogen and progesterone receptors in endometrium in women with unexplained infertility.

AIM: The purpose of the present study is to evaluate the relationship between endometrial concentrations of estrogen and progesterone receptors throughout the menstrual cycle in women with unexplained infertility. MATERIAL AND METHODS: In forty four infertile women with unexplained infertility, biopsy of the endometrium was performed during simultaneous laparoscopy and hysteroscopy. Material was prepared for immunohistochemical staining. Forty four endometrial samples obtained from women with normal menstrual cycles were divided into four categories: early proliferative, late proliferative, early secretory and late secretory. Immunohistochemical localization of estrogen receptors (ER) and progesterone receptors (PR) was scored according to intensity of staining and proportion of cells specifically stained in glandular epithelium and stroma and results were analyzed. CONCLUSION: The early secretory phase appeared to be period of transition from the strong and ubiquitous staining for receptor characteristic of proliferative phase of endometrium to the weak, focal pattern of estrogen receptors. Progesterone receptors in early secretory phase were of strong staining and sufficient number of stained cells.

Peritumoral p53 expression in oral carcinoma.

p53 is one of the most frequently mutated genes in human tumors including head and neck tumors like oral squamous cell carcinoma. It might be responsible for more than 50% of all relapses in patients with surgically treated oral carcinoma and clean margins. The aim of the present study was to explore p53 protein expression in peritumoral tissue and correlate it with relapse of the disease. The study included 25 patients (17 males and 8 females) with oral squamous cell carcinoma in the period August 2006 till August 2008. For immunohistochemical assay, a monoclonal antibody against p53 protein was applied (clone DO-7, DAKO Glostrup, Denmark). Peritumoral expression of p53 was as follows: 10 out of 25 cases (40%) were negative, 2 cases (8%) showed weak, 5 cases (20%) moderate and 8 cases (32%) strong p53 positivity. No significant correlation between peritumoral expression of p53 protein and patient's relapse was found. In contrast, we found a trend toward association between intratumoral p53 expression and patient's relapse (p = 0.07). There was also trend toward higher peritumoral p53 expression in females comparing with p53 expression in males (52.9% of males did not have p53 expression while 87.5% females had mild, moderate or high p53 expression, p = 0.088). Peritumoral expression of p53 protein is frequently seen in oral squamous cell carcinoma and merits further research.