Caratterizzazione dei melanomi mucosi: studio del microambiente immunologico e del profilo molecolare per sviluppare terapie mirate

I melanomi mucosi (MM) sono neoplasie rare che originano dai melanociti delle mucose con una patogenesi non correlata alla fotoesposizione solare. Il distretto testa-collo, in particolare il cavo orale e il tratto sinonasale, rappresentano la sede pi\uf9 comune di insorgenza. La prognosi di questa neoplasia \ue8 infausta ed i motivi che possano spiegare questa aggressivit\ue0 sono ancora sconosciuti e richiedono studi di biologia molecolare specifici. \uc8 stata condotta un\u2019analisi retrospettiva su 48 pazienti affetti da MM sinonasale, trattati in due centri italiani di riferimento dal 2000 al 2017. I dati clinici e i fattori prognostici sono stati analizzati. Materiale tissutale adeguato per ogni singolo caso \ue8 stato selezionato negli archivi. \uc8 stata condotta un\u2019analisi immunoistochimica per analizzare il microambiente immunologico dei casi tumorali, utilizzando anticorpi specifici (CD45, CD8, CD3, CD163, CD20, CD66b, BDCA2, CD56, CD274/PD-L1, HLA-DP, DQ, DR. The PD-L1, \u3b2-catenin, e PTEN). Sono state generate delle linee di coltura cellulare e sono state identificate cellule staminali tumorali specifiche. L\u2019analisi mutazionale genetica \ue8 stata condotta utilizzando il sistema Sequenom MassArray ed il sistema il targeted next generation sequencing (NGS). Delezioni/duplicazioni delle regioni cromosomiche 1p, 3, 6 e 8 sono state ricercate utilizzando le sonde SALSA MLPA (Multiplex Ligation-dependent Probe Amplification) P027 Uveal Melanoma. I risultati del presente studio hanno dimostrato che questa neoplasia pu\uf2 essere considerata come un \u201cnoninflammed tumor\u201d con un microambiente immunologico caratterizzato da scarso infiltrato di cellule CD45, CD8 e CD3. Inoltre, l\u2019espressione di PDL-1 \ue8 risultata sempre assente. Questo ambiente immunologico \u201cfreddo\u201d potrebbe spiegare l\u2019efficacia limitata dei protocolli immunoterapici con doppio inibitore di checkpoint immunitario (anti-PD-1/e anti-CTLA4) che sono stati impiegati negli ultimi anni. L\u2019analisi mutazionale ha evidenziato la presenza di mutazioni somatiche nei geni NRAS, KRAS e KIT solo in 14/31 casi. In particolare, non sono state osservate mutazioni di BRAF in nessuno dei casi analizzati, cosa che \ue8 completamente in contrasto con il profilo genetico che classicamente caratterizza i melanomi cutanei. Dal punto di vista genomico, \ue8 stato possibile descrivere un profilo muticromosomico specifico di alterazioni nel numero di copie, caratterizzato da \u201closs\u201d del cromosoma 3p-q, 1p e 8p. Questo profilo, quando presente, \ue8 in grado di identificare un sottogruppo di pazienti caratterizzato da prognosi infausta ed elevato rischio di metastatizzazione precoce. Sebbene questo profilo di alterazioni genomiche non abbia una ricaduta terapeutica specifica al momento attuale, questo risultato potrebbe essere molto utile per aiutare nell\u2019identificazione dei pazienti a prognosi peggiore ed elevato rischio di metastasi che potrebbero essere candidati a forme di trattamento neoadiuvante e/o adiuvante pi\uf9 intensificate. In conclusione, questo studio dimostra come il MM rappresenti un\u2019entit\ue0 tumorale completamente diversa dal melanoma cutaneo dal punto di vista della patogenesi, dell\u2019epidemiologia, del decorso clinico e del profilo genetico-molecolare. Per questo motivo \ue8 importante inquadrare questi pazienti in modo specifico per proporre loro forme di trattamento mirato. A questo proposito, terapie target molecolare con MEK-inhibitors, PI3K-AKT-mTOR inhibitors, CDK4/6 inhibitors, KRASG12C inhibitors, tyrosine kinase inhibitors (Imatinib, Nilotinib, Avapritinib), e multikinase inhibitors (Regorafenib) potrebbero essere proposte per questi pazienti, in base al loro stato mutazionale. Inoltre, trattamenti immunoterapici combinati con inibitori di doppio check point immunitario (anti-CTLA-4 e anti-PD-1) potrebbero essere usati per questi pazienti sia nel setting neoadiuvante che come forma di trattamento adiuvante.Mucosal melanoma (MM) is a highly aggressive and rare form of melanoma arising from mucosal melanocytes with a pathogenesis unrelated to sun exposure. Head and neck, in particular the oral cavity and the sinonasal tract (SN), represent the most common MM sites. MM outcome is very poor and the reasons behind this aggressive clinical behavior are only partially understood. A retrospective review of 48 patients treated for sinonasal tract mucosal melanoma in two Italian tertiary care referral centres (University of Insubria, Varese, and University of Brescia) from 2000 to 2017 was performed. Clinical data, survival outcomes and prognostic factors have been fully analyzed. Tissue blocks were retrieved from Institutional archives. Immunohistochemical evaluation of the immunological tumor microenvironment was performed by testing different antibodies, such as CD45, CD8, CD3, CD163, CD20, CD66b, BDCA2, CD56, CD274/PD-L1, HLA-DP, DQ, DR. The PD-L1, \u3b2-catenin, and PTEN immunostaining were also performed. Cell lines were generated and cancer stem cells were identified. Gene mutation analysis was performed both using Sequenom MassArray system and targeted next generation sequencing (NGS) analysis. Deletions/duplications analysis of regions in chromosomes 1p, 3, 6 and 8 was performed using SALSA MLPA (Multiplex Ligation-dependent Probe Amplification) probemix P027 Uveal Melanoma. We found that MM is a noninflammed tumor with an immune contexture poor of CD45, CD8 and CD3 positive cells. In addition to the scarce immune infiltration, PDL-1 expression is almost absent in MM. This \u201ccold\u201d immune contexture may explain the limited efficacy of immunotherapy, even in the form of double immune checkpoint inhibitor anti-PD-1/anti-CTLA4, which has been observed in MM patients. When considering the molecular landscape of MM, we found somatic mutations only in 14/31 cases, mainly involving NRAS, KRAS and KIT. No BRAF mutations were found, in contrast with the genetic fingerprint of cutaneous melanoma. From genomic viewpoint, we described a multichromosome copy number aberration signature characterized by chromosome 3p-q losses together with 1p loss and 8p loss, which is associated with poor prognosis and early systemic metastasization risk. Although this genomic signature at present does not have a direct therapeutic implication, it may be useful in identifying patients at high risk for early dissemination of disease and poor prognosis, who might benefit from intensification of systemic treatments in neoadjuvant or adjuvant setting. In conclusion, we found that MM should be considered as clinical entity significantly different from cutaneous melanoma with regard to its pathogenesis, epidemiology, clinical characteristics and genetic-molecular fingerprint. As such, it is important to evaluate these patients as a separate subset in order to give patients realistic expectations for their disease course and to propose them specific forms of treatment. In this regards, in well selected cases, target-therapies with MEK-inhibitors, PI3K-AKT-mTOR inhibitors, CDK4/6 inhibitors, KRASG12C inhibitors, tyrosine kinase inhibitors (Imatinib, Nilotinib, Avapritinib), and multikinase inhibitors (Regorafenib) should be considered, based on the molecular profile. In addition, immunotherapy with double immune check points inhibitors (anti-CTLA-4 and anti-PD-1) might be used in selected cases both in neoadjuvant and adjuvant setting

Molecular Biomarkers in Sinonasal Cancers: New Frontiers in Diagnosis and Treatment

Purpose of Review: Sinonasal tumors are rare and heterogeneous diseases which pose challenges in diagnosis and treatment. Despite significant progress made in surgical, oncological, and radiotherapy fields, their prognosis still remains poor. Therefore, alternative strategies should be studied in order to refine diagnosis and improve patient care. Recent Findings: In recent years, in-depth molecular studies have identified new biological markers, such as genetic abnormalities and epigenetic variations, which have allowed to refine diagnosis and predict prognosis. As a consequence, new histological entities have been described and specific subgroup stratifications within the well-known histotypes have been made possible. These discoveries have expanded indications for immunotherapy and targeted therapies in order to reduce tumor spread, thus representing a valuable implementation of standard treatments. Summary: Recent findings in molecular biology have paved the way for better understanding and managing such rare and aggressive tumors. Although further efforts need to be made in this direction, expectations are promising

Sinonasal mucosal melanoma: Molecular profile and therapeutic implications from a series of 32 cases

BACKGROUND: Primary sinonasal mucosal melanomas are aggressive tumors with a poor clinical control by current treatments, raising the urgent need of novel strategies. METHODS: By fluorescence in situ hybridization (FISH), direct sequencing, and immunohistochemistry, we investigate the spectrum of molecular abnormalities in a cohort of 32 cases of primary sinonasal mucosal melanomas. RESULTS: We found that all primary sinonasal mucosal melanomas lack BRAF V600E mutation; in addition, they are characterized by somatic mutations of NRAS (22%) and KIT (12.5%), together with amplification of RREB1 (100%) and loss of MYB (76%). The large majority of cases showed KIT protein expression (96.9%). Among tumor suppressor genes, primary sinonasal mucosal melanomas showed loss of PTEN (48.1%) and p16/INK4a (55.2%). All tested cases showed expression of pAkt and pErk, suggesting a combined activation of PI3K/Akt and RAS-mitogen-activated protein kinase (MAPK) pathways. CONCLUSIONS: This molecular fingerprint strongly argues against the clinical efficacy of BRAF-inhibitors, but could candidate primary sinonasal mucosal melanomas to therapeutic strategies targeting RAS and KIT mutations or inhibiting PI3K-Akt-mTOR pathway

Palatovaginal (pharyngeal) artery: clinical implication and surgical experience

The palatovaginal or pharyngeal artery is a small branch of the internal maxillary artery supplying the nasopharynx. Bleeding from this artery is exceptional and only one case of traumatic epistaxis from this artery has been reported previously. We report a case of a 66-year-old male presenting with right recurrent posterior epistaxis. Endoscopic dissection of the pterygopalatine fossa and direct visualization of the palatosphenoidal canal permitted to identify the origin of bleeding, and coagulation of the pharyngeal artery solved the epistaxis. Although rare, intractable posterior epistaxis may arise from the pharyngeal artery. The anatomical knowledge of this artery and of the palatosphenoidal canal is of outmost importance in endoscopic transpterygoid and nasopharyngeal procedures, to identify the vidian canal, evaluate nasopharyngeal cancer spread in the pterygopalatine fossa, reduce bleeding during surgery of the nasopharynx, and harvest adequately the pedicle of the nasoseptal flap

A 3-dimensional transnasal endoscopic journey through the paranasal sinuses and adjacent skull base: a practical and surgery-oriented perspective

An endoscopic approach through the transnasal corridor is currently the treatment of choice in the management of benign sinonasal tumors, cerebrospinal fluid leaks, and pituitary lesions. Moreover, this approach can be considered a valid option in the management of selected sinonasal malignancies extending to the skull base, midline meningiomas, parasellar lesions such as craniopharyngioma and Rathke cleft cyst, and clival lesions such as chordoma and ecchordosis. Over the past decade, strict cooperation between otorhinolaryngologists and neurosurgeons and acquired surgical skills, together with high-definition cameras, dedicated instrumentation, and navigation systems, have made it possible to broaden the indications of endoscopic surgery. Despite these improvements, depth perception, as provided by the use of a microscope, was still lacking with this technology. The aim of the present project is to reveal new perspectives in the endoscopic perception of the sinonasal complex and skull base thanks to 3-dimensional endoscopes, which are well suited to access and explore the endonasal corridor. In the anatomic dissection herein, this innovative device came across with sophisticated and long-established fresh cadaver preparation provided by one of the most prestigious universities of Europe. The final product is a 3-dimensional journey starting from the nasal cavity, reaching the anterior, middle, and posterior cranial fossae, passing through the ethmoidal complex, paranasal sinuses, and skull base. Anatomic landmarks, critical areas, and tips and tricks to safely dissect delicate anatomic structures are addressed through audio comments, figures, and their captions

Typical and Atypical Symptoms of Petrous Apex Cholesterol Granuloma: Association with Radiological Findings

Objective: Petrous apex cholesterol granuloma (PACG) is a lesion that can give rise to different symptoms, and correlations with etiopathology are ambiguous. The aim of this study is to analyze the association between PACG symptoms and radiological findings at presentation, in order to establish a reproduceable pre-operative radiological evaluation and guide the surgical indication. Methods: PACG patients were collected in two tertiary care hospitals. All cases underwent CT/MRI to evaluate the cyst localization and erosion of surrounding structures. Typical and atypical symptoms were then analyzed and compared to radiologic findings established in accordance with the literature. Results: Twenty-nine patients were recruited; the most common symptoms were headache (69%), diplopia (20.7%) and fainting (24.1%), an atypical clinical manifestation related to jugular tubercle involvement. Significant associations between symptoms and radiologic findings were noted in terms of headache and temporal lobe compression (p = 0.04), fainting and jugular tubercle erosion (p < 0.001), vestibular symptoms and internal auditory canal erosion (p = 0.02), facial paresthesia and Meckel’s cave compression (p = 0.03), diplopia and Dorello canal involvement (p = 0.001), and tinnitus and cochlear basal turn erosion (p < 0.001). All patients were treated via an endoscopic–endonasal approach, in which extension was tailored to each case. At a median follow-up of 46 months, 93.1% of patients experienced resolution of symptoms. Conclusions: This clinico-radiological series demonstrates associations between symptoms and anatomical subsites involved with PACG. Hence, it may guide the surgeon at the time of surgical decision, since it asserts that typical and atypical symptoms are actually related to PACG