Sinonasal Tumors Research Articles

A study of benign sino-nasal tumors in rural tertiary care hospital

Background: The sino-nasal unit, although anatomically a very small space, is quite exceptional in the sense that an eclectic mix of neoplastic tumors originate from here. The diverse nature of the neoplastic pathologies and their unique natural histories prompted for this study. Methods: In this prospective study of two years, done in a rural tertiary care hospital of India, 46 patients with benign neoplastic tumors of nasal cavity, sinuses and nasopharynx were analyzed for their clinic-pathological and radiological profile and surgical management. Results: The incidence of benign tumor was predominant in second decade (34.8%) with significant male preponderance (M:F ratio 2.28:1). Unilateral nasal obstruction (100%) and epistaxis (84.8%) were the two most common presenting complaints. Almost half (48%) of the patients presented as late as more than one year after the onset of the symptoms. Nasal cavity was the commonest site of the tumors (50%). The most common benign tumor in present study was capillary hemangioma (41.31%) followed by angiofibroma (26.09%). All tumors were removed by a standard functional endoscopic sinus surgery or combined approach. Except a single case of inverted papilloma, all the other cases showed no recurrence at the end of one year follow up period. Conclusions: It can be concluded from present study that conjoint application of radiology, endoscopy and histopathology is of utmost importance in dealing with benign neoplastic pathology of sino-nasal region. There is significant success in managing benign sino-nasal tumors with functional endoscopic sinus surgery or by combined approach.

Clinical Outcome in Patients with Large Sinonasal Tumors with Intracranial Extension.

Objectives Malignant tumors of the sinonasal cavities with extension to the frontal skull base are rare and challenging pathologies. Combined-approach surgery using a frontobasal craniotomy and endoscopic sinus surgery with reconstruction of the anterior skull base followed by adjuvant radiotherapy is a preferred treatment strategy in selected cases. Morbidity and mortality rates are high in this population. We aim to add our experience to the current literature. Design We performed a retrospective cross-sectional single center study of the long-term clinical outcome in a tertiary university referral hospital in the Netherlands between 2010 and 2021. Descriptive statistics and frequency distributions were performed Participants Patient, tumor, treatment, complications and survival characteristics of eighteen consecutive patients were extracted from the electronic health records. Main Outcome Measures The primary outcome measures are progression free survival, overall survival and complication rate. Results Eighteen consecutive patients were included with a mean age of 61 (SD ± 10) years (range 38-80); ten males and eight females. Gross total resection was achieved in 14 (77%) patients. Eleven (61%) patients underwent local radiotherapy, one (5%) chemotherapy and three (17%) a combination of both. Mean follow-up duration was 49 months (range 3 - 138). Three (17%) patients died in hospital due to post-operative complications. Six (33%) patients died during follow-up due to disease progression. Mean progression-free survival was 47 months (range 0 - 113). Conclusion In conclusion, the overall survival was 50% for this group of patients with large sinonasal tumors. Progressive disease affects survival rate severely. Surgical complications were seen in five (28%) patients. Radiotherapy is associated with high complication rates. Radiation necrosis was a serious complication in two patients and could be treated with high dose steroids.

Long-term outcomes of modern multidisciplinary management of sinonasal cancers: The M. D. Anderson experience.

To report long-term outcomes of modern radiotherapy for sinonasal cancers. A retrospective analysis of patients with sinonasal tumors treated with intensity-modulated radiotherapy or proton therapy. Multivariate analysis was used to determine predictive variables of progression free survival (PFS) and overall survival (OS). Three hundred and eleven patients were included, with median follow-up of 75 months. The most common histologies were squamous cell (42%), adenoid cystic (15%), and sinonasal undifferentiated carcinoma (15%). Induction chemotherapy was administered to 47% of patients; 68% had adjuvant radiotherapy. Ten-year local control, regional control, distant metastasis free survival, PFS, and overall survival rates were 73%, 88%, 47%, 32%, and 51%, respectively. Age, non-nasal cavity tumor site, T3-4 stage, neck dissection, and radiation dose were predictive of PFS, while age, non-nasal cavity tumor site, T3-4 stage, positive margins, neck dissection, and use of neoadjuvant chemotherapy were predictive of OS. There was a 13% rate of late grade ≥3 toxicities. This cohort of patients with sinonasal cancer treated with modern radiotherapy demonstrates favorable disease control rate and acceptable toxicity profile.

Cancers rares de la tête et du cou sous l’égide du REFCOR, partie 2

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology as well as their anatomical location when arising from the paranasal sinuses, salivary glands and ear. The management of these heterogeneous rare diseases of complex treatment has considerably been structured over the last 15years, in particular via the French ENT Cancer Expertise Network (REFCOR) and international networks and registries (EURACAN, etc.). Structuration also favors research with identification of new entities and setting up of specific therapeutic trials. A first article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the REFCOR concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. This second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

Cancers rares de la tête et du cou sous l’égide du REFCOR, partie 1

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology, which determines their local invasiveness, and their hematogenous/nodal spread. Their diagnosis can be difficult and often requires comprehensive immunohistochemistry and genomic techniques. Expert pathology review is recommended in the cases of undifferentiated tumors, sarcomas and at the slightest diagnostic doubt. These rare cancers can also be rare by their anatomical location when arising from the paranasal sinuses, salivary glands and ear. Their location requires knowledge of their specific extension routes, and may call for a specific surgical technique (skull base endoscopic sinus surgery, extended total parotidectomy, etc.) and adapted radiotherapy to spare healthy organs surrounding the tumor. This article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the French ENT Cancer Expertise Network (REFCOR) concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. A second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

Small Round Blue Cell Tumours of the Sinonasal Area: Our 5 year Experience in a Tertiary Care Centre in India.

Purpose: The main purpose of this study is to understand the characteristics and management of sinonasal small round blue cell tumors and also to emphasise the role of immunohistochemistry in their diagnosis and on the outcomes after endoscopic/open excision in these patients. Methods: This is a retrospective study conducted at a tertiary care referral centre in India which included 38 patients with sino nasal for a period of 5 years. All the patients were evaluated clinically and radiologically. All cases were confirmed diagnostically with histopathological examination and immunohistochemistry following surgical excision either by endoscopic or open approach. Some of the cases underwent post operative radiotherapy. Results: In our study, among 176 cases diagnosed with Sino nasal malignancies, 38 (21.6%) cases were diagnosed with sinonasal small round blue cell tumors with male to female ratio 1.4:1. Most common histopathological type among all the sinonasal small round blue cell tumors that presented to us was esthesioneuroblastoma i.e., 8 (21%) patients followed by pituitary macroadenoma in 7(8.4%) patients. Other types are undifferentiated squamous cell carcinoma 10(13.1%), craniopharyngioma 8(10.5%), lymphoma 3(7.9%), synovial/spindle cell sarcoma, malignant melanoma and adenocarcinoma 1(2.6%) each. Schwannoma, rhabdomyosarcoma, neuroendocrine carcinoma and neurofibroma 2 (5.2%) each. Conclusion: Sinonasal small round blue cell tumors are extremely rare tumours. Histopathological diagnosis with immunohistochemistry is characteristic of various tumors and is conclusive for diagnosis. Knowledge of these tumor entity is essential as early diagnosis helps in further management in preventing spread to vital structures and improving outcome. Most of the tumors have a multimodality treatment approach which includes surgical excision, radiotherapy and chemotherapy.

Sinonasal Inflammation or Neoplasm: Raise the Red Flagsǃ-A Pictorial Review.

Inflammatory pathology remains the most common indication for sinonasal imaging. However, sinonasal region is also the epicenter of a variety of neoplasms. These are often missed both clinically and radiologically owing to nonspecific signs and symptoms and subtle imaging pointers. An early diagnosis of sinonasal neoplasms is critical for timely management and hence better prognosis and survival rate. This pictorial review aims to acquaint the reader with the "red flag" signs on computed tomography that should raise suspicion for an underlying neoplastic pathology and also highlights the imaging features of common sinonasal neoplasms.

The SINTART 2 Study. A phase II non-randomised controlled trial of induction chemotherapy, photon-, proton- and carbon-ion-based radiotherapy integration in patients with locally advanced unresectable sinonasal tumours

PurposeUnresectable, locally advanced sinonasal epithelial tumours are rare diseases with poor prognosis. Multimodal approach is widely used, although no standard therapy has been established in prospective trials. This study assessed activity and safety of an innovative integration of multimodality treatment—induction chemotherapy (ICT), surgery and radiotherapy (RT)—modulated by histology and response to ICT. MethodsPatients with untreated, unresectable sinonasal epithelial tumours with selected histotypes (squamous cell carcinoma, intestinal-type adenocarcinoma, sinonasal undifferentiated and neuroendocrine carcinoma, olfactory neuroblastoma) were enroled in a single-arm, open-label, phase II, multicentre clinical trial. Patients were treated with up to 5 ICT cycles, whose regimen was selected according to histotype. Photon and/or proton/carbon-ion-based RT was employed according to disease site, stage and ICT response. Primary end-point was 5-years progression-free survival (PFS), secondary end-points were overall survival (OS), ICT objective response rate per RECIST 1.1 and safety. ResultsTwenty-five patients were evaluable for primary end-point. Five-year PFS was 26.8% (95% confidence interval [CI]: 12.6–57.1), with a median PFS of 18 months. Five-year OS was 23.8% (95% CI: 9.5–59.3), with a median OS of 27 months. The overall response rate to ICT was 40%. Three-year PFS for patients achieving major volumetric partial response (mPRv) versus non-mPRv was 40% (95% CI: 13.7–100%) versus 23.1% (95% CI: 8.3–64.7%) (P = 0.318) and 3-year OS was 53.3% (95% CI: 21.4–100%) versus 37.7% (95% CI: 20.0–71.0%) (P = 0.114). ConclusionMultimodal combination of ICT and innovative RT did not provide a significant improvement in survival rates with respect to previous experiences. This finding underscores the need for future research in this rare disease, still characterised by a heavy burden and poor prognosis. We observed longer survival in subjects achieving response to ICT. The overall treatment safety is acceptable.

The SINTART 1 study. A phase II non-randomised controlled trial of induction chemotherapy, surgery, photon-, proton- and carbon ion-based radiotherapy integration in patients with locally advanced resectable sinonasal tumours

PurposeSinonasal tumours are rare diseases with poor prognosis. Multimodal approach including surgery is widely used, although no standard therapy has been established in prospective trials. This study assessed activity and safety of an innovative integration of multimodality treatment—induction chemotherapy (ICT), surgery and radiotherapy (RT)—modulated by histology and response to ICT. MethodsPatients with untreated, operable sinonasal tumours with selected histotypes (squamous cell carcinoma, intestinal-type adenocarcinoma, sinonasal undifferentiated and neuroendocrine carcinoma, olfactory neuroblastoma) were enrolled in a single-arm, phase II, multicenter clinical trial. Patients were treated with up to 5 ICT cycles, whose regimen was selected according to histotype, followed either by curative chemo-RT for pts with ≥80% reduction of initial tumour diameter or surgery and adjuvant (chemo)RT. Photon and/or proton/carbon ion-based RT was employed according to the disease site and stage. Primary end-point was 5-year progression-free survival (PFS), secondary end-points were overall survival (OS), ICT objective response rate (ORR) per RECIST 1.1 and safety. ResultsThirty-five patients were evaluable for primary end-point. Fourteen patients (40%) were treated with definitive (CT)RT and 20 (57%) underwent surgery. Five-year PFS was 38% (95% confidence interval [CI], 21–69), with a median PFS of 26 months. Five-year OS was 46% (95% CI, 28–75), with a median OS of 36 months. Three-year PFS—OS for pts achieving PR/CR versus stable disease (SD)/PD to ICT were 49.8–57% versus 43.2–53%, respectively. Three-year PFS for patients achieving major volumetric partial response (≥80% reduction of initial tumour volume, major partial volumetric response [mPRv]) versus non-mPRv were 82% versus 28% and 3-year OS were 92% versus 36% (p value 0.010 and 0.029, respectively). The ORR to ICT was 54% and 60% across all histotypes and in the sinonasal undifferentiated carcinoma (SNUC) subpopulation, respectively, with 6/15 SNUCs (40%) achieving mPRv. ConclusionTreatment of advanced sinonasal cancer with histology-driven ICT followed by (CT)RT in responsive patients was feasible. Overall, these findings suggest a possible role of ICT as the primary approach in newly diagnosed, resectable sinonasal tumours—especially SNUC—to select patients with favourable prognosis. Histology heterogeneity limits generalisation of trial results.

A case series of rare sinonasal tumors

Sinonasal tumors often mimick inflammatory diseases. If misdiagnosed, results are life threatening. This article comprises of study done on 5 patients who presented with nasal mass. They underwent clinical examination, diagnostic nasal endoscopy, radiology and histopathological examination (HPE). Thorough evaluation helps the surgeon diagnose rare cases thus preventing detrimental outcomes. Herein we describe our experience with rare tumors like glomangiopericytoma, embryonal rhabdomyosarcoma, small cell sinonasal carcinoma, inverted papilloma and sinonasal undifferentiated carcinoma (SNUC).

Top 10 Significant Spindled Head and Neck Lesions to Scrutinze.

Spindled lesions are a challenging area in head and neck pathology. This is particularly true in the sinonasal tract, where several uncommon entities with both unique and overlapping morphologic, immunophenotypic, and/or molecular features can occur. Review. The clinicopathologic characteristics of biphenotypic sinonasal sarcoma and nine important differential diagnostic considerations with one or more overlapping feature are summarized to establish a practical framework for approaching spindled lesions of the sinonasal tract. Morphologic evaluation is central to the work up of sinonasal spindle cell lesions-in particular, cellular morphology, tumor architecture and growth pattern, and the presence of admixed epithelial elements - however, focused immunohistochemical analysis of neural, myogenic, rhabdomyoblastic, epithelial, and/or melanocytic marker expression and/or ancillary tests for tumor-specific molecular alterations may be necessary for definitive diagnosis.

Top Ten Oncocytic Head and Neck Lesions to Contemplate.

Oncocytes are a component of many metaplastic and neoplastic lesions throughout the head and neck area, primarily originating in salivary/seromucinous glands and the thyroid gland. In addition, other lesions can contain cells that mimic oncocytes (pseudo-oncocytes); these can be of epithelial or non-epithelial origin. Review article. Oncocytic metaplasia is common in seromucinous glands throughout the upper aerodigestive tract, most notable in the oral cavity, nasopharynx and larynx. The main oncocytic salivary gland neoplasms are Warthin tumor and oncocytoma. Infarction of Warthin tumor may lead to recognition difficulties. Oncocytic subtypes of mucoepidermoid carcinoma and intraductal carcinoma have morphologic and immunohistochemical features that allow distinction from major oncocytic entities. Oncocytic thyroid tumors include adenoma, carcinoma (follicular, papillary and medullary), along with poorly differentiated tumors. Oncocytic papillary sinonasal and middle ear tumors must be distinguished from low grade adenocarcinomas. Pseudo-oncocytic entities include paraganglioma, Langerhans cell histiocytosis, giant cell tumor, rhabdomyoma, and metastatic tumors. Correct diagnosis of oncocytic head and neck lesions requires a knowledge of the spectrum of possible entities, their characteristic sites of occurrence, architecture, histomorphology, and immunohistochemistry. Oncocytic subtypes of several newly described entities are now recognized. Both epithelial and non-epithelial mimics of oncocytes exist. The molecular features of oncocytic tumors can be helpful in their diagnosis and understanding their pathogenesis.

Advances in Endoscopic Surgical Approaches for Sinonasal Tumors

Advances in Endoscopic Surgical Approaches for Sinonasal Tumors

Sinonasal Adenosquamous Carcinoma - Morphology and Genetic Drivers Including Low- and High-Risk Human Papillomavirus mRNA, DEK::AFF2 Fusion, and MAML2 Rearrangement.

Sinonasal adenosquamous carcinoma is rare, and there are almost no studies detailing morphology or characterizing their genetic driver events. Further, many authors have termed sinonasal tumors with combined squamous carcinoma and glands as mucoepidermoid carcinoma but none have analyzed for the presence of MAML2 rearrangement. Cases from 2014 to 2020 were collected and diagnosed using World Health Organization criteria. They were tested for p16 expression by immunohistochemistry (70% cut-off), DEK::AFF2 fusion by fluorescence in situ hybridization (FISH) and AFF2 immunohistochemistry, MAML2 rearrangement by FISH, and low- and high-risk HPV by RNA ISH and reverse transcription PCR, respectively. Detailed morphology and clinical features were reviewed. There were 7 male (64%) and 4 female (36%) patients with a median age of 69 years, most Caucasian (10 of 11 or 91%). Most had tobacco exposure (8/11, 73%) and most presented with epistaxis, a visible nasal mass, and/or facial pain. Several had a precursor papillomas (3 of 11, 27%). The squamous component had variable keratinization, 5 of 11 (46%) of which would be described as keratinizing, 3 non-keratinizing, and 2 with mixed features. All had gland formation, by definition, and 2 of 11 (18%) had ciliated tumor cells. None of the 11 cases had MAML2 rearrangement and one had DEK::AFF2 fusion with associated positive nuclear AFF2 protein immunostaining. Most were p16 positive (7 of 11, 64%) and all 7 of these were hrHPV positive either by RNA ISH or RT-PCR. Two of the p16-negative tumors were positive for lrHPV by RNA ISH. Treatment included surgery alone (4 of 11, 36%), surgery with adjuvant radiation (5 of 11, 45%), and surgery with radiation and chemotherapy (2 of 11, 18%). Four of 11 patients (36%) suffered disease recurrence, two requiring re-operation and who were disease free at last follow-up, one receiving additional chemotherapy and who was alive with disease. The other elected to undergo palliative therapy and died of disease. Sinonasal adenosquamous carcinoma is a somewhat heterogeneous tumor not infrequently arising ex papilloma and having various drivers including high- and low-risk HPV and rarely DEK::AFF2 fusion. The prognosis appears favorable when proper treatment is possible.

Diagnostic performance of MRI for the assessment of extraocular muscle invasion in malignant sinonasal tumors.

Preoperative assessment of extraocular muscle invasion is essential for therapeutic strategies and prognostic evaluation. The aim of this study was to assess the diagnostic accuracy of MRI for evaluation of extraocular muscle (EM) invasion by malignant sinonasal tumors. Consecutively, 76 patients of sinonasal malignant tumors with orbital invasion were included in the present study. Preoperative MRI imaging features were analyzed by two radiologists independently. The diagnostic performances of MR imaging features for detecting EM involvement were evaluated by comparing imaging findings to histopathology data. A total of 31 extraocular muscles were involved by sinonasal malignant tumors in 22 patients, including 10 medial rectus muscles (32.2%), 10 inferior rectus muscles (32.2%), 9 superior oblique muscles (29.1%), and 2 external rectus muscles (6.5%). The EM involved by sinonasal malignant tumors usually showed relatively high signal intensity on T2-weighted images, indistinguishable from the tumor, nodular enlargement and abnormal enhancement (p = 0.001, < 0.001, < 0.001 and < 0.001, respectively). Using a combination of EM abnormal enhancement and indistinguishable from the tumor in multivariate logistic regression analysis, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for detecting orbital EM invasion by sinonasal tumors were 93.5, 85.2, 76.3, 96.3and 88%, respectively. MRI imaging features show high diagnostic performance for the diagnosis of extraocular muscle invasion by malignant sinonasal tumors.

Sinonasal Organised Haematoma- A Case Report and Review of Literature.

Sinonasal organised haematoma (SOH) is an uncommon, benign condition that can be locally aggressive. SOH can be mistaken for a malignant tumour but the characteristic imaging findings and histopathology facilitate the diagnosis of an organised haematoma. We report a 26 year old male patient presenting with unilateral nasal obstruction and painless epistaxis, which are the most common presenting symptoms of sinonasal tumour lesions. Based on the clinical features, age, radiological investigation, intraoperative finding, location of the lesion and histopathological examination; a diagnosis of SOH was arrived at. Surgical excision utilized the COBLATION technology and endoscopic complete removal of the nasal mass was done. Intraoperatively minimal bleeding was encountered. On histopathology, haematoma at the center and fibrosis at the periphery was noted. To our knowledge, this is the first reported case of SOH excision using Coblator. No recurrence was seen in subsequent follow ups. Although SOH can be mistaken for a malignant tumour, the characteristic imaging and histopathology findings facilitate the diagnosis of an organised haematoma.

SIGNIFICANCE OF NASAL SEPTUM ANGULATION AND ITS ASSOCIATION WITH RHINOSINUSITIS USING SYMPTOMS SCORES AND VISUAL ANALOGUE SCALE

Objective- The aim of the study is to determine the association of angulation of nasal septum with the severity of rhinosinusitis as measured by symptom score and visual analog score. Materials and methods- 50 patients who were diagnosed with rhinosinusitis and fullled the selection criteria were assessed for symptom score and VAS and measurement of angulation of nasal septum was performed through a coronal view of CT paranasal sinuses in bone window setting. Patients older than 18 years, diagnosed with rhinosinusit Inclusion criteria- is and carrying indications for CT scan of paranasal sinuses were included in the study. Patients with history of nasal Exclusion criteria trauma, septal surgery, septal haematoma ,septal perforation, concha bullosa, sinonasal tumors were excluded from the study. Results- The result obtained from one-way ANOVA test revealed a signicant association between category of severity of septal angulation and the symptom score of rhinosinusitis. Severity of nasal septum angulation may be signicantly asso Conclusion- ciated with severity of rhinosinusitis based on symptom score and VAS.these ndings could be used in management of patient with rhinosinusitis during functional endoscopic sinus surgery

A Combined Surgical Approach for the Treatment of a Sino-Naso-Orbital Glomangiopericytoma

Glomangiopericytomas are a rare type of sinonasal tumors with high relapse rates. Endoscopic sinus surgery is the classical technique to remove such tumors. Here we report a case of sinonasal glomangiopericytoma with orbital extension, infrequently described in the literature. A 50 year-old woman was referred to our hospital because of a right paranasal painless swelling, which appeared 9 months ago and was slowly increasing in size since her first visit. A Magnetic Resonance Imaging (MRI) revealed a tumor (18 × 25 × 37 mm) centered on the right ethmoidal cells, with adjacent nasal bone erosion and a right orbital invasion. The tumor was removed with a combined surgical approach (endoscopic and trans-sinusal frontal approach) after pre-surgical embolization. Based on the results of the histopathological examination, the diagnosis of a glomangiopericytoma was confirmed. The patient was discharged after one week, and an uneventful long-term follow-up.

Translocations and Gene Fusions in Sinonasal Malignancies.

During the past few years there has been an expansion in our understanding of gene fusions and translocations involved in cancer of the sinonasal tract. Here we review the downstream biologic effects, clinical characteristics, and pathologic features of these tumors. The molecular consequences and neo-antigens resulting from these chromosomal aberrations are considered and targets for current and future clinical trials discussed. Several new, clinically relevant, chromosomal aberrations have been discovered and evaluated to varying degrees in sinonasal tumors including DEK::AFF2, BRD4::NUT, ADCK4::NUMBL, and ETV6::NTRK3. Sinonasal malignancies demonstrate a diverse genetic landscape and varying clinical courses. Recent studies illustrate that gene fusions and translocations may play a role in carcinogenesis in certain sinonasal tumor subtypes and may be used to develop new biomarker-driven and patient-centered treatments.

Identification of an Activating PDGFRA Deletion in a Novel Sinonasal Soft Tissue Neoplasm.

Spindle cell tumours in the sinonasal area are diagnostically challenging. We identified a neoplasm that defied histopathological classification using current criteria. The case was subjected to histopathological, immunohistochemical and molecular analysis using a large small variant DNA panel. The tumour comprised cytologically bland epithelioid spindle cells with a rich vasculature, which lack expression of actin and other smooth muscle markers, CD34 and beta-catenin. An activating insertion/deletion in exon 12 of the PDGFRA gene was detected. This alteration has previously been described in gastrointestinal stromal tumours and inflammatory fibroid polyps of the GI tract, but the site, histological, and immunophenotypic features in this tumour are distinct. We describe a novel sinonasal spindle cell tumour characterised by an activating insertion/deletion in exon 12 of PDGFRA. The diagnosis of PDGFRA-activated sinonasal spindle cell tumour should be considered in difficult to classify mesenchymal lesions at this site.