IntroductionHead and neck cancer (HNC) comprises a diverse group of oncological entities, originating from various tissue types and organ localizations, situated in the topographical regions of the head and neck (H&N). This single institution retrospective study was aimed at establishing the HNC patient demographics and categorizing the individual incidence of H&N malignancies, regarding their organ of origin and main histopathological type.Materials and methodsAll histologically verified cases of HNC from a single tertiary referral center were reviewed in a descriptive retrospective manner. Data sampling period was 47 months.ResultsMale to female ratio of the registered HNC cases was 3.24:1. The mean age of diagnosis was 63.84 ± 12.65 years, median 65 years. The most common HNC locations include the larynx 30.37% (n = 188), lips and oral cavity 29.08% (n = 180), pharynx 20.03% (n = 124) and salivary glands 10.94% (n = 68), with other locations such as the external nose, nasal cavity and sinuses and auricle and external ear canal harboring a minority of the cases. The main histopathological groups include squamous cell carcinoma 76.74% (n = 475) and adenocarcinoma 6.14% (n = 38), with other malignant entries such as other epithelial malignancies, primary tonsillar, mucosa-associated lymphoid tissue or parenchymal lymphomas, connective tissue neoplasias, neuroendocrine and vascular malignancies diagnosed in a minority of cases.ConclusionConsidered to be relatively rare, HNC represents a diverse group of oncological entities with individual and specific demographic characteristics. The reported single institution results appear representative of the national incidence and characteristics of HNC.

IntroductionIntracranial tumors (ICTs) are a diverse group of malignancies that pose an immediate threat to patients' lives, no matter their local or metastatic origin, benign or malignant nature. These lesions have severe clinical courses and need to be diagnosed and treated as soon as possible, with pathological verification being the pivotal moment in the process of determining curative modalities.AimThe aim of this study was to compare the incidence of histologically confirmed ICTs in Eastern Bulgaria, based on their type (primary, metastatic, and non-volume occupying lesions (NVOL)), their respective subtypes, and incidence in a descriptive manner.Materials and MethodsFor a period of five full calendar years (January 1st, 2012 – December 31st, 2016), all histologically confirmed cases of intracranial tumors were prospectively collected from two individual tertiary healthcare institutions. The cases were then statistically analyzed in a descriptive manner, and incidences of primary, metastatic, and NVOL were compared with regards to their specific origins, types, and subtypes. Metastatic tumors were further segregated relative to their intracranial metastatic location.ResultsThe total number of individual ICTs registered in the set timeframe was 822. Primary ICTs represented a total of 66.12% of the histologically confirmed cases, with the most common entries being tumors from a glial and meningeal origin, 30.90% were histologically confirmed as metastatic ICTs, from which the most common entries were of pulmonary origin, and the other 2.94% were NVOL. On behalf of their intracranial metastatic location, metastatic tumors were located predominantly in the supratentorial region, represented as a total of 87.80%, while the other 12.20% were located in the subtentorial region. Based on the descriptive analysis, the annual incidence per 100,000 capita of all ICTs is 9.12, comprised of 6.03 per 100,000 for primary ICTs, 2.82 per 100,000 for metastatic ICTs, and 0.27 per 100,000 for NVOL. The annual incidence of the most commonly diagnosed primary ICTs per 100,000 is 2.36 for meningioma, 2.03 for glioblastoma, and 0.48 for pituitary adenoma. The annual incidence of the most commonly diagnosed metastatic ICTs per 100,000 is 1.32 for lung cancer metastases, 0.28 for gastrointestinal tract (GIT) metastases, 0.22 for melanoma, and 0.17 for breast cancer metastases.ConclusionBased on our results, primary ICTs are operated and biopsied more than two times as much as metastatic ICTs and only a small fraction of neurosurgical interventions are undertaken due to NVOL. Metastatic ICTs are predominantly supratentorial with no evidence of a tumor predominantly metastasizing in the subtentorial region. The demographics reported in the study establish some aspects of age and gender preferences, as well as the annual incidence per 100,000 for the most commonly diagnosed types of ICTs in our population.

BackgroundGlioblastoma multiforme (GBM) is a class IV astrocytic tumor, the most malignant of the four groups of World Health Organization (WHO) tumors with astrocytic differentiation.AimThe aim of this study was to estab­lish whether a correlation exists between the Ki-67 index of tumors with astrocytic differentiation, WHO grade, and patient survival.Materials and methodsA retrospective non-clinical approach to patient selection was chosen for the aim of the study. A total of 47 patients diagnosed and treated for CNS tumors with astrocytic differentiation in the St. Marina University Hospital, Varna, Bulgaria, from September 2012 to July 2016 were retrospectively included into the study cohort. The cases were tested for their immunohistochemistry (IHC) reaction with Ki-67 after their original Hematoxylin and Eosin and IHC slides were reviewed by a single author and blind coded. The Ki-67 positivity index of the nuclei was estimated after digitalization of the slides and calculated by the ImmunoRatio automated count­ing tool. The individual Ki-67 index and patient survival of each case were statistically compared.ResultsThe histopathological groups, after the blind Ki-67 index automated calculation was carried out, revealed no WHO grade I, two WHO grade II samples, four WHO grade III samples and 41 WHO grade IV cases, and these were included in the analysis. The two samples of WHO grade II astrocytic tumors had a mean Ki-67 index of 25%; however, they comprised tumors with an individual index of 43% and 7%, both individual values with a highly unlikely index for this group. The four samples of WHO grade III had a mean Ki-67 index of 4%, standard deviation ±2.16 (p>0.05), with the lowest index being 1% and the highest one being 6%. Both WHO grade II and III did not include enough samples to allow for a proper statistical analysis of patient survival. The 41 GBM cases had a mean Ki-67 index of 17.34%, standard deviation ±10.79 (p>0.05). Statistical analysis of the Ki-67 index divid­ed dichotomously into two groups and patient survival revealed that cases with a high Ki-67 index had no significant difference in survival when compared to those with low expression.ConclusionsBased on the reported results, the mean Ki-67 percentage of positive nuclei in GBM tumor sam­ples cannot be used to estimate the survival of patients. However, Ki-67 remains a valuable IHC pathological tool.

Intracranial tumors (ICTs) attract numerous scientific teams and tremendous financial resources worldwide. These lesions of the central nervous system (CNS) can be both benign and malignant in biological behavior as well as local or metastatic in origin. We compared data from two studies on primary and metastatic ICTs from Brazil and Bulgaria, based on histopathologically confirmed ICTs from tertiary health centers. Primary ICTs significantly outweigh the frequency of metastatic ICTs. Primary ICTs represent 86.45% in Brazil and 69.17% in Bulgaria, with around 60% of their totals being malignant. There is a statistical dominance of tumors from the neuroepithelial origin, with the most common entry being glioblastoma multiforme. The second-most common primary ICT group comprises tumors of meningeal origin. Metastatic ICTs show great variance; 13.55% in Brazil and 31.38% in Bulgaria of all ICT cases being attributed to them. However, metastatic ICTs are even a more diverse group than neuroepithelial tumors, with the majority of this group comprising metastatic colorectal adenocarcinoma (almost exclusively in males), metastatic breast adenocarcinoma in females, metastatic pulmonary carcinomas (primarily from the non-small cell group with a male predominance), and metastatic melanoma with an even gender ratio.

Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited disorder of cardiomyocyte-to-cardiomyocyte adhesion proteins associated with ventricular arrhythmias and sudden cardiac death. It is a characterized by progressive fibrofatty replacement of right ventricular myocardium. The presence of adipose tissue either with or without fibrous tissue, scattered among cardiomyocytes is the histological hallmark of the disease. Being in the myocardium, adipocytes trigger damage to cardiomyocytes, thus causing electrical instability of the right ventricular myocardium, but the molecular pathogenesis of such an electrical instability in ARVD is still unclear. Since (i) adipose tissue replacement of cardiomyocytes is the most essential histological finding in ARVD, (ii) nerve growth factor (NGF) exerts an arrhythmogenic effect related to sudden cardiac death, and (iii) adipose tissue produces NGF and brain-derived neurotrophic factor (BDNF), the aim of the present study is to analyze immunohistochemically ARVD-related adipocytes with special attention to the expression of NGF and related neurotrophins, BDNF and neurotrophin-3 (NT-3) and their respective TrkA, TrkB and TrkC receptors. Eight cases with ARVD were autopsy proven. The present results demonstrate that the intramyocardial adipocytes and cardiomyocytes in ARVD express NGF/TrkA and NT-3/TrkC, suggesting that they may play a substantial part in life-threatening myocardial electrical instability.