Lymphoma presenting as preauricular tumor in unilateral parotid gland agenesis: a case report and review of literature.

BACKGROUND: Parotid gland agenesis is a rare, congenital, usually asymptomatic disorder. Until now, only 24 cases with unilateral, incidentally found, parotid gland agenesis have been described. Here, we present the first reported case of an ipsilateral preauricular neoplasm in a patient with unilateral parotid gland agenesis. During surgery, the position of the greater auricular- and facial nerves was documented. Furthermore, we performed the first sialendoscopy for this rare disorder to assess the number of duct branches, which might be indicative of the abundance of parotid tissue. Moreover, we looked for sialendoscopic characteristic features that could aid in identifying these patients in the ambulatory setting. CASE PRESENTATION: A 50-year-old Greek man presented with a painless, slowly enlarging mass in the right parotid space. Magnetic resonance imaging revealed a complete absence of the right parotid gland without accessory parotid tissue. The right parotid gland was replaced by fatty tissue and the radiologist suggested a benign parotid tumor. Fine needle aspiration was indicative of a reactive lymph node. Sialendoscopy revealed only two branches within the right parotid duct. Surgical resection was performed through a conventional lateral parotidectomy. This revealed typical anatomic position of the greater auricular- and facial nerves despite the parotid tissue agenesis. Histopathology revealed a small lymphocytic lymphoma. CONCLUSIONS: Surgeons should feel confident to resect tumors of the parotid space in patients with parotid gland agenesis. Reduced branching observed during sialendoscopy might indicate parotid gland agenesis. Physicians should be even more cautious than usual with the watch and wait strategy in patients with tumors of parotid gland agenesis, since the probability of a tumor being a benign salivary gland tumor might be lower than usual.

PD-L1 Expression in Neoplastic and Immune Cells of Thymic Epithelial Tumors: Correlations with Disease Characteristics and HDAC Expression.

BACKGROUND: Programmed death-ligand 1 (PD-L1) expression in neoplastic and immune cells of the tumor microenvironment determines the efficacy of antitumor immunity, while it can be regulated at the epigenetic level by various factors, including HDACs. In this study, we aim to evaluate the expression patterns of PD-L1 in thymic epithelial tumors (TETs), while we attempt the first correlation analysis between PD-L1 and histone deacetylases (HDACs) expression. METHODS: Immunohistochemistry was used to evaluate the expression of PD-L1 in tumor and immune cells of 91 TETs with SP263 and SP142 antibody clones, as well as the expressions of HDCA1, -2, -3, -4, -5, and -6. RESULTS: The PD-L1 tumor proportion score (TPS) was higher, while the immune cell score (IC-score) was lower in the more aggressive TET subtypes and in more advanced Masaoka-Koga stages. A positive correlation between PD-L1 and HDAC-3, -4, and -5 cytoplasmic expression was identified. CONCLUSIONS: Higher PD-L1 expression in neoplastic cells and lower PD-L1 expression in immune cells of TETs characterizes more aggressive and advanced neoplasms. Correlations between PD-L1 and HDAC expression unravel the impact of epigenetic regulation on the expression of immune checkpoint molecules in TETs, with possible future applications in combined therapeutic targeting.

Searching for Novel Biomarkers in Thymic Epithelial Tumors: Immunohistochemical Evaluation of Hippo Pathway Components in a Cohort of Thymic Epithelial Tumors.

Given the pivotal role of the Hippo pathway in different facets of tumorigenesis, which has been vigorously established in multiple heterogenous malignancies, we attempted to evaluate its potential utility as a prognostic-predictive biomarker in thymic epithelial tumors (TETs). For this purpose, we performed a comprehensive immunohistochemical analysis of four Hippo cascade components (YAP, TAZ, TEAD4 and LATS1) in a sizeable cohort of TETs and attempted to identify possible correlations of their H-score with various clinicopathological parameters. TAZ and TEAD4 displayed both cytoplasmic and nuclear immunoreactivity in almost equal frequency, with their cytoplasmic H-score being strongly associated with more aggressive high-grade tumors (type B3, thymic carcinoma) and more advanced pathological stages. On the other hand, a primarily nuclear staining pattern was encountered in both YAP and LATS1, with the YAP nuclear H-score being higher in more indolent (type A) and earlier stage tumors. Interestingly, none of the four examined factors displayed any statistically significant correlation with patient overall (OS) or disease-free survival (DFS). In summary, our results provide some initial insight into the expression profile of these core Hippo pathway components in thymic neoplasms and point towards some clear associations with tumor characteristics, which are of paramount translational-clinical research with profound implications in therapeutic targeting of this pathway in the context of precision medicine.

Histone Deacetylases (HDACs): Promising Biomarkers and Potential Therapeutic Targets in Thymic Epithelial Tumors.

Histone deacetylases (HDACs) are core epigenetic factors, with pivotal roles in the regulation of various cellular procedures, and their deregulation is a major trait in the acquisition of malignancy properties. In this study we attempt the first comprehensive evaluation of six class I (HDAC1, HDAC2, HDAC3) and II HDACs (HDAC4, HDAC5, HDAC6) expression patterns in thymic epithelial tumors (TETs), with the aim of identifying their possible association with a number of clinicopathological parameters. Our study revealed higher positivity rates and expression levels of class I enzymes compared to class II. Sub-cellular localization and level of staining varied among the six isoforms. HDAC1 was almost exclusively restricted to the nucleus, while HDAC3 demonstrated both nuclear and cytoplasmic reactivity in the majority of examined specimens. HDAC2 expression was higher in more advanced Masaoka-Koga stages, and displayed a positive correlation with dismal prognoses. The three class II HDACs (HDAC4, HDAC5, HDAC6) exhibited similar expression patterns, with predominantly cytoplasmic staining, that was higher in epithelial rich TETs (B3, C) and more advanced tumor stages, while it was also associated with disease recurrence. Our findings could provide useful insights for the effective implementation of HDACs as biomarkers and therapeutic targets for TETs, in the setting of precision medicine.

Predicting lymphoma in Sjögren's syndrome and the pathogenetic role of parotid microenvironment through precise parotid swelling recording.

OBJECTIVE: Parotid swelling (PSW) is a major predictor of non-Hodgkin's lymphoma (NHL) in primary SS (pSS). However, since detailed information on the time of onset and duration of PSW is scarce, this was investigated to verify whether it may lead to further improved prediction. NHL localization was concomitantly studied to evaluate the role of the parotid gland microenvironment in pSS-related lymphomagenesis. METHODS: A multicentre study was conducted among patients with pSS who developed B cell NHL during follow-up and matched controls that did not develop NHL. The study focused on the history of salivary gland and lachrymal gland swelling, evaluated in detail at different times and for different durations, and on the localization of NHL at onset. RESULTS: PSW was significantly more frequent among the cases: at the time of first referred pSS symptoms before diagnosis, at diagnosis and from pSS diagnosis to NHL. The duration of PSW was evaluated starting from pSS diagnosis, and the NHL risk increased from PSW of 2-12 months to >12 months. NHL was prevalently localized in the parotid glands of the cases. CONCLUSION: A more precise clinical recording of PSW can improve lymphoma prediction in pSS. PSW as a very early symptom is a predictor, and a longer duration of PSW is associated with a higher risk of NHL. Since lymphoma usually localizes in the parotid glands, and not in the other salivary or lachrymal glands, the parotid microenvironment appears to be involved in the whole history of pSS and related lymphomagenesis.

Unraveling the Role of Histone Variant CENP-A and Chaperone HJURP Expression in Thymic Epithelial Neoplasms.

Background: Recent advances demonstrate the role of chromatin regulators, including histone variants and histone chaperones, in cancer initiation and progression. Methods: Histone H3K4me3, histone variant centromere protein (CENP-A) and histone chaperones Holliday junction recognition protein (HJURP) as well as DAXX expression were examined immunohistochemically in 95 thymic epithelial tumor (TET) specimens. Our results were compared with the expression profile of DAXX, HJURP and CENP-A in gene expression profiling interactive analysis (GEPIA2). Results: The lymphocyte-poor B3- and C-type TETs were more frequently DAXX negative (p = 0.043). B3 and C-Type TETs showed higher cytoplasmic and nuclear CENP-A (p = 0.007 and p = 0.002) and higher cytoplasmic HJURP H-score (p < 0.001). Higher nuclear CENP-A and cytoplasmic HJURP expression was associated with advanced Masaoka−Koga stage (p = 0.048 and p < 0.001). A positive correlation between HJURP and CENP-A was also observed. The presence of cytoplasmic CENP-A expression was correlated with a favorable overall survival (p = 0.03). CENP-A overexpression in survival analysis of TCGA TETs showed similar results. H3K4me3 expression was not associated with any clinicopathological parameters. Conclusions: Our results suggest a significant interaction between CENP-A and HJURP in TETs. Moreover, we confirmed the presence of a cytoplasmic CENP-A immunolocalization, suggesting also a possible favorable prognostic value of this specific immunostaining pattern.

Unraveling the Immune Microenvironment of Thymic Epithelial Tumors: Implications for Autoimmunity and Treatment.

Thymic Epithelial Tumors (TETs) represent a rare tumor family, originating from the epithelial component of the thymus gland. Clinicopathologically, they are segregated into six major subtypes, associated with distinct histological features and clinical outcomes. Their emergence and evolution are accompanied by the generation of a complex tumor microenvironment (TME), dominated by phenotypically and functionally divergent immune cellular subsets, in different maturation states and in analogies that vary significantly among different subtypes. These heterogenous leukocyte populations exert either immune-permissive and tumor-suppressive functions or vice versa, and the dynamic equilibrium established among them either dictates the tumor immune milieu towards an immune-tolerance state or enables the development of a productive spontaneous tumoricidal response. The immunologically "hot" microenvironment, defining a significant proportion of TETs, makes them a promising candidate for the implementation of immune checkpoint inhibitors (ICIs). A number of phase I and II clinical trials have already demonstrated significant, type-specific clinical efficacy of PD-L1 inhibitors, even though substantial limitations in their utilization derive from their immune-mediated adverse effects. Moreover, the completed clinical studies involved relatively restricted patient samples and an expansion in the enrolled cohorts is required, so that more trustworthy conclusions regarding the benefit from ICIs in TETs can be extracted.

Ephrin Receptors (Ephs) Expression in Thymic Epithelial Tumors: Prognostic Implications and Future Therapeutic Approaches.

Ephrin receptors (Ephs) are receptor tyrosine kinases (RTKs) implicated in tissue development and homeostasis, and they are aberrantly expressed in tumors. Here, immunohistochemical Eph type-A and -B expression in thymic epithelial tumors (TETs) was assessed and correlated with clinicopathological parameters. Tissue microarrays from 98 TETs were stained for EphA1, -A2, -A4 -A6, -B1, -B2, -B4 and -B6. The relationship between neoplastic and lymphoid cell immunoreactivity score (H-score), histopathological parameters (Pearson's test) and survival of 35 patients (Mantel-Cox model) was explored. Epithelial-rich subtypes showed higher EphA6 cytoplasmic H-score (B2/B3, carcinoma) (p < 0.001) and stronger EphA4 H-score (B3, carcinoma) (p = 0.011). The immature T-cells, especially in subtypes AB/B1, had higher EphB6 H-score than carcinoma-associated mature lymphocytes (p < 0.001); carcinomas had higher lymphocytic EphB1 H-score (p = 0.026). Higher lymphocytic and lower epithelial EphB6 H-score correlated with Masaoka stage ≤II (p = 0.043, p = 0.010, respectively). All cases showed variable epithelial and lymphocytic EphA2 expression, but clinicopathological associations were not reached. Our study confirmed that Eph type-A and -B expression in TETs is associated with established prognostic parameters, i.e., tumor subtype and Masaoka stage, although correlation with patient survival was not reached. Such findings suggest involvement of these RTKs in thymic neoplasia, as well as their potential utility as treatment targets.

Histone Deacetylase (HDAC)-1, -2, -4, and -6 in Uveal Melanomas: Associations with Clinicopathological Parameters and Patients' Survival.

BACKGROUND: Uveal melanoma (UM) represents the most common primary intraocular malignancy in adults, exerting high metastatic potential and poor prognosis. Histone deacetylases (HDACs) play a key role in carcinogenesis, and HDAC inhibitors (HDACIs) are currently being explored as anti-cancer agents in clinical settings. The aim of this study was to evaluate the clinical significance of HDAC-1, -2, -4, and -6 expression in UM. METHODS: HDAC-1, -2, -4, and -6 expression was examined immunohistochemically in 75 UM tissue specimens and was correlated with tumors' clinicopathological characteristics, the presence of tumor-infiltrating lymphocytes (TILS), as well as with our patients' overall survival (OS). RESULTS: HDAC-2 was the most frequently expressed isoform (66%), whereas we confirmed in addition to the expected nuclear expression the presence of cytoplasmic expression of class I HDAC isoforms, namely HDAC-1 (33%) and HDAC-2 (9.5%). HDAC-4 and -6 expression was cytoplasmic. HDAC-1 nuclear expression was associated with increased tumor size (p = 0.03), HDAC-6 with higher mitotic index (p = 0.03), and nuclear HDAC-2 with epithelioid cell morphology (p = 0.03) and presence of tumor-infiltrating lymphocytes (p = 0.04). The association with the remaining parameters including Monosomy 3 was not significant. Moreover, the presence as well as the nuclear expression pattern of HDAC-2 were correlated with patients' improved OS and remained significant in multivariate survival analysis. CONCLUSIONS: These findings provide evidence for a potential role of HDACs and especially HDAC-2 in the biological mechanisms governing UM evolution and progression.

SOX11, CD70, and Treg cells configure the tumor-immune microenvironment of aggressive mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a mature B-cell neoplasm with a heterogeneous clinical and biological behavior. SOX11 oncogenic expression contributes to the aggressiveness of these tumors by different mechanisms, including tumor and stromal cell interactions. However, the precise composition of the immune cell microenvironment of MCL, its possible relationship to SOX11 expression, and how it may contribute to tumor behavior is not well known. Here, we performed an integrative transcriptome analysis of 730 immune-related genes combined with the immune cell phenotype analysis by immunohistochemistry in SOX11+ and SOX11- primary nodal MCL cases and non-neoplastic reactive lymph nodes. SOX11+ MCL had a significant lower T-cell intratumoral infiltration compared with negative cases. A reduced expression of MHCI/II-like and T-cell costimulation and signaling activation related transcripts was significantly associated with poor clinical outcome. Moreover, we identified CD70 as a SOX11 direct target gene, whose overexpression was induced in SOX11+, but not SOX11- tumor cells by CD40L in vitro. CD70 was overexpressed in primary SOX11+ MCL and it was associated with an immune unbalance of the tumor microenvironment characterized by increased number of effector regulatory t (Treg) cell infiltration, higher proliferation, and aggressive clinical course. CD27 was expressed with moderate to strong intensity in 76% of cases. Overall, our results suggest that SOX11 expression in MCL is associated with an immunosuppressive microenvironment characterized by CD70 overexpression in tumor cells, increased Treg cell infiltration and downmodulation of antigen processing, and presentation and T-cell activation that could promote MCL progression and represent a potential target for tailored therapies.

Extracellular Vesicles as Biomarkers Carriers in Bladder Cancer: Diagnosis, Surveillance, and Treatment.

Exosomes are extracellular vesicles, enriched in biomolecular cargo consisting of nucleic acids, proteins, and lipids, which take part in intercellular communication and play a crucial role in both physiologic functions and oncogenesis. Bladder cancer is the most common urinary malignancy and its incidence is steadily rising in developed countries. Despite the high five-year survival in patients diagnosed at early disease stage, survival substantially drops in patients with muscle-invasive or metastatic disease. Therefore, early detection of primary disease as well as recurrence is of paramount importance. The role that exosomal biomarkers could play in bladder cancer patient diagnosis and surveillance, as well as their potential therapeutic applications, has not been extensively studied in this malignancy. In the present review, we summarize all relevant data obtained so far from cell lines, animal models, and patient biofluids and tissues. Current literature suggests that urine is a rich source of extracellular vesicle-derived biomarkers, compared with blood and bladder tissue samples, with potential applications in bladder cancer management. Further studies improving sample collection procedures and optimizing purification and analytical methods should augment bladder cancer diagnostic, prognostic, and therapeutic input of extracellular vesicles biomarkers in the future.

Immunotherapy in uveal melanoma: novel strategies and opportunities for personalized treatment.

INTRODUCTION: Uveal melanoma (UM) is the most common intraocular cancer and represents a discrete subtype of melanoma. Metastatic disease, which occurs in half of patients, has a dismal prognosis. Immunotherapy with immune checkpoint inhibitors has produced promising results in cutaneous melanoma but has failed to show analogous efficacy in metastatic UM. This is attributable to UM's distinct genetics and its complex interaction with the immune system. Hence, more efficacious immunotherapeutic approaches are under investigation. AREAS COVERED: We discuss those novel immunotherapeutic strategies in clinical and preclinical studies for advanced disease and which are thought to overcome the hurdles set by UM in terms of immune recognition. We also highlight the need to determine predictive markers in relation to these strategies to improve clinical outcomes. We used a simple narrative analysis to summarize the data. The search methodology is located in the Introduction. EXPERT OPINION: Novel immunotherapeutic strategies focus on transforming immune excluded tumor microenvironment in metastatic UM to T cell inflamed. Preliminary results of approaches such as vaccines, adoptive cell transfer and other novel molecules are encouraging. Factors such as HLA compatibility and expression level of targeted antigens should be considered to optimize personalized management.

Salivary gland cancer in the era of immunotherapy: can we exploit tumor microenvironment?

INTRODUCTION: Salivary gland cancers (SGCs) consist of a rare family of neoplasms with varying histology and biological behavior. Therapeutic regimens have been relatively unchanged for decades. The recent successes of immunotherapy have raised hopes for the development of more effective strategies in SGC, thus emphasizing the role of tumor microenvironment (TME) in the design for more effective therapies. AREAS COVERED: This review presents an overview of the current knowledge on the pathobiology of SGC TME and discusses the potential of immunotherapeutic targeting. EXPERT OPINION: Most data on the role of TME in SGC carcinogenesis are derived from preclinical studies. Signaling cascades of immunotherapeutic interest, PD-1/PD-L1 and PD-1/PD-L2, are active in many SGCs and might be associated with biological behavior and prognosis. Immunotherapeutic attempts are very limited, but recent findings in other tumors on the role of exosomes and PD-L2 signaling suggest that TME of SGCs warrants further research, emphasizing larger cohorts, histology-based stratification, and standardized evaluation of immunomodulatory molecules, to explore the potential of targeting tumor stroma and its signaling cascades. Furthermore, combination of immunotherapies or immunotherapies with the antineoplastic agents targeting AR, HER2, and tyrosine kinases, recently introduced in SGC treatment, constitutes a promising approach for the future.

Exosomes in Nephropathies: A Rich Source of Novel Biomarkers.

The biomarkers commonly utilized in diagnostic evaluations of kidney disease suffer from low sensitivity, especially in the early stages of renal damage. On the other hand, obtaining a renal biopsy to augment clinical decision making can lead to potentially serious complications. In order to overcome the shortcomings of currently available diagnostic tools, recent studies suggest that exosomes, cell-secreted extracellular vesicles containing a large array of active molecules to facilitate cell-to-cell communication, may represent a rich source of novel disease biomarkers. Because of their endocytic origin, exosomes carry markers typical for their parent cells, which could permit the localization of biochemical cellular alterations in specific kidney compartments. Different types of exosomes can be isolated from noninvasively obtained biofluids; however, in the context of kidney disease, evidence has emerged on the role of urinary exosomes in the diagnostic and predictive modeling of renal pathology. The current review summarizes the potential application of exosomes in the detection of acute and chronic inflammatory, metabolic, degenerative, and genetic renal diseases.

Pure Red Cell Aplasia Caused by Azathioprine.

BACKGROUND: Pure Red Cell Aplasia (PRCA) is a clinical entity comprising severe normochromic normocytic anemia, reticulocytopenia, erythroblastopenia in the bone marrow, with normal leukocyte and platelets count. PRCA can be classified into congenital and acquired, with the latter characterized as idiopathic or secondary to various infections, hematological malignancies, collagen vascular diseases, thymoma, and exposure to a variety of drugs and other chemical substances. METHODS: Herein, we present a female patient, who presented with PRCA due to azathioprine treatment. RESULTS: Prompt discontinuation of the drug together with red blood cells transfusions led to complete recovery in this young patient, without any addition of immunosuppressive regimen. CONCLUSION: We followed 'the wait and see practice' instead of administering immunosuppression to our patient, after careful consideration and extensive consultation with our hematologists. This 'wait and see practice' proved to be effective in the long run.

Pulmonary nocardiosis associated with Cushing's disease: a case report.

Nocardia spp. is a genus of Gram-positive bacteria which can cause cutaneous, pleuropulmonary, or disseminated disease. The latter two forms are encountered in immunocompromised patients, with prolonged usage of corticosteroids being a well-recognized risk factor. However, endogenous Cushing's syndrome is less frequently associated with nocardiosis. We report on a 40-year-old woman who presented for further workup of abnormal findings in the chest computed tomography (three lung nodules, one of which being cavitary). She underwent trans-thoracic fine-needle lung aspiration of the cavitary nodule, which led to the diagnosis of lung nocardiosis. Moreover, the identification of cushingoid features from the history and clinical examination initiated further investigation with hormonal laboratory assessment and bilateral inferior petrosal sinus sampling which established the diagnosis of pituitary adrenocorticotropic hormone (ACTH) hypersecretion (Cushing's disease).  We conclude that pulmonary nocardiosis can be an opportunistic infection as well as a presenting manifestation of Cushing's disease.

The Role of Exosomes in Bone Remodeling: Implications for Bone Physiology and Disease.

Bone remodeling represents a physiological phenomenon of continuous bone tissue renewal that requires fine orchestration of multiple cell types, which is critical for the understanding of bone disease but not yet clarified in precise detail. Exosomes, which are cell-secreted nanovesicles drawing increasing attention for their broad biosignaling functions, can shed new light on how multiple heterogeneous cells communicate for the purpose of bone remodeling. In the healthy bone, exosomes transmit signals favoring both bone synthesis and resorption, regulating the differentiation, recruitment, and activity of most cell types involved in bone remodeling and even assuming an active role in extracellular matrix mineralization. Additionally, in the ailing bone, they actively participate in pathogenic processes constituting also potential therapeutic agents and drug vectors. The present review summarizes the current knowledge on bone exosomes and bone remodeling in health and disease.

Ovarian metastasis of renal cell carcinoma: Clinical and pathological presentation of a case.

A 82-year-old woman was referred to our hospital with complaints of weight loss, loss of appetite, abdominal pain and a palpable pelvic mass. Abdominal imaging revealed a tumour at the upper pole of the right kidney with a maximum diameter of 8 cm and a second tumour in the pelvis, mostly solid, with a maximum diameter of 16 cm, that seemed to originate from the left ovary. As she was initially considered to have two distinct tumours, through a single transabdominal incision, she simultaneously underwent right radical nephrectomy and also bilateral salpingo-oophorectomy for the tumour that originated from the left ovary. Histopathological examination showed that the tumour in the right kidney was a clear-cell renal cell carcinoma (RCC) (stage pT3a, Fuhrman grade 2). The ovarian tumour proved to be an ovarian fibroma that included a circumscribed focus with a diameter of 0.7 cm which was a metastasis from the kidney tumour. Immunohistochemistry contributed significantly to the diagnosis, as the focus showed strong and diffuse expression of CD10 and RCC antigen, which are reliable markers of RCC. With less than 30 reported cases in the literature, it is very important to differentiate ovarian metastasis of RCC from primary ovarian tumour due to different treatment alternatives and prognosis.

Exosomes in sarcomas: Tiny messengers with broad implications in diagnosis, surveillance, prognosis and treatment.

Exosomes are cell-secreted extracellular vesicles, which contain an array of biomolecules, such as proteins, mRNAs, microRNAs, and lipids, take part in intercellular communication and mediate tumor-host interactions. They are increasingly considered as a source of biomarkers for liquid biopsies as well as potential drug vectors. Sarcomas are rare malignant mesenchymal tumours and due to their relative rarity exosomes have not been investigated in as extensively as in epithelial malignancies. Nonetheless, valuable information has been gathered over the last years on the roles of exosomes in sarcomas. In the present review we summarize all relevant data obtained so far from cell lines, animal models and patients with emphasis on their potential clinical utility.