SMARCA4-deficient sinonasal carcinoma: A series of 10 cases expanding the genetic spectrum of SWI/SNF-driven sinonasal malignancies

The molecular pathogenesis of poorly differentiated sinonasal carcinoma received significant attention in recent years. As a consequence, several unclassified carcinomas in the morphologic spectrum of sinonasal undifferentiated carcinoma have been reclassified as distinctive genetically defined variants or entities. Among the latter are NUT-rearranged carcinoma and SMARCB1-deficient carcinomas. In this study, we further characterize a rare variant of sinonasal undifferentiated carcinoma-like tumors characterized by inactivation of the SWItch/Sucrose Nonfermentable chromatin remodeler SMARCA4 (BRG1) detectable by immunohistochemistry. Patients were 7 males and 3 females aged 20 to 67 years (median, 44). Tumors originated in the nasal cavity (6), nose and sinuses (2), or at unspecified site (2). Six tumors were initially misdiagnosed as small cell neuroendocrine carcinoma (SCNEC) or large cell neuroendocrine carcinoma (LCNEC). Histologically, the tumors were composed of small basaloid (3 cases) or large epithelioid (7) cells disposed into nests and solid sheets with extensive areas of necrosis. No glands or other differentiating features were noted. Abortive rosettes were seen in 1 case. Immunohistochemistry showed consistent expression of pankeratin and absence of CK5, p63, p16, and NUT in all tumors tested. Other tested markers were variably positive: CK7 (2/6), synaptophysin (9/10; mostly focal and weak), chromogranin-A (4/10; focal), and CD56 (3/5; focal). All tumors showed total loss of SMARCA4 and retained expression of SMARCB1/INI1. Co-loss of SMARCA2 was seen in 1 of 8 cases. Limited data were available on treatment and follow-up. Two patients received surgery (1 also radiotherapy) and 3 received chemotherapy. Metastases (cervical nodes, liver, bone, and lung/mediastinal) were detected in 3 patients; 2 were alive under palliative chemotherapy at 8 and 9 months while 1 died of progressive lung disease at 7 months. Three patients (1 with brain invasion) died soon after diagnosis (1 to 3 mo). In total, 4 of 6 patients (66%) with follow-up died of disease (median, 3 mo). This series characterizes SMARCA4-deficient sinonasal carcinoma as a genetically distinct aggressive entity in the spectrum of undifferentiated sinonasal carcinomas. These variants add to the spectrum of SWItch/Sucrose Nonfermentable-deficient sinonasal carcinomas, at the same time expanding the topographic distribution of SMARCA4-related malignancies

Molecular and immunologic analysis of laryngeal squamous cell carcinoma in smokers and non-smokers

139th Annual Spring Meeting of the American-Laryngological-Association (ALA) at Combined Otolaryngology Spring Meetings (COSM) -- APR 18-20, 2018 -- National Harbor, MDBackground: Laryngeal squamous cell carcinoma (LSCC) is strongly associated with tobacco use, but recent reports suggest an increasing incidence of LSCC in patients without traditional risk factors, suggesting an alternative etiology of tumorigenesis. The purpose of this study is to characterize this non-smoking population and to compare immunohistochemical markers in tumor specimens from non-smokers and smokers with LSCC. Methods: A retrospective chart review of patients with LSCC at Johns Hopkins Hospital (JHH) was performed. A tissue microarray (TMA) was constructed with tumor specimen from non-smokers with stage and age-matched smokers and stained for a variety of immunologic and molecular targets. Results: In the JHH cohort of 521 patients, 12% (n = 63) were non-smokers. Non-smokers were more likely to be < 45 years old at time of diagnosis (OR 4.13, p = 0.001) and to have glottic tumors (OR 2.46, p = 0.003). The TMA was comprised of tumors from 34 patients (14 non-smokers, 20 smokers). Only 2 patients (6%) were human-papillomavirus (HPV) positive by high-risk RNA in situ hybridization (ISH). There was no correlation between smoking status and p16 (p = 0.36), HPV-ISH positivity (p = 0.79), phosphatase and tensin homolog (PTEN, p = 0.91), p53 (p = 0.14), or programmed death-ligand 1 (PD-L1, p = 0.27) expression. Conclusions: Non-smokers with LSCC are more likely to be younger at the time of diagnosis and have glottic tumors than smokers with LSCC. In TMA analysis of stage and age-matched specimens from smoker and nonsmokers with LSCC, the pattern of expression for common molecular and immunologic markers is similar. Further, HPV does not appear to be a major causative etiology of LSCC in either smokers or non-smokers in our cohort of patients.Amer Laryngol AssocNIDCD Mentored Patient-Oriented Research Career Development Award [1K23DC014758]; NATIONAL INSTITUTE ON DEAFNESS AND OTHER COMMUNICATION DISORDERSUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Deafness & Other Communication Disorders (NIDCD) [K23DC014758] Funding Source: NIH RePORTERNIDCD Mentored Patient-Oriented Research Career Development Award 1K23DC014758 (S. Best)

Comprehensive molecular profiling of sinonasal teratocarcinosarcoma highlights recurrent SMARCA4 inactivation and CTNNB1 mutations

Sinonasal teratocarcinosarcoma (TCS) is a rare tumor defined by intermixed neuroepithelial, mesenchymal, and epithelial elements. While its etiology was historically ambiguous, we recently reported frequent SMARCA4 loss by immunohistochemistry, suggesting that TCS might be related to SMARCA4-deficient sinonasal carcinomas. However, other molecular alterations including CTNNB1 mutation have been reported in TCS, and its full genetic underpinnings are unclear. Here, we performed the first comprehensive molecular analysis of sinonasal TCS to better understand its pathogenesis and classification. We collected 30 TCS including 22 cases from our initial study. Immunohistochemical loss of SMARCA4 was seen in 22 cases (73%), with total loss in 18 cases (60%). β-catenin showed nuclear localization in 14 cases (64%) of the subset tested. We selected 17 TCS for next-generation sequencing with enrichment for partial or intact SMARCA4 immunoexpression. We identified inactivating SMARCA4 mutations in 11 cases (65%) and activating CTNNB1 mutations in 6 cases (35%), including 5 cases with both. Of 5 cases that lacked SMARCA4 or CTNNB1 mutation, 2 harbored other SWI/SNF complex and Wnt pathway alterations, including 1 with SMARCB1 inactivation and 1 with concomitant APC and ARID1A mutations, and 3 had other findings, including DICER1 hotspot mutation. These findings confirm that SMARCA4 inactivation is the dominant genetic event in sinonasal TCS with frequent simultaneous CTNNB1 mutations. They further underscore a possible relationship between TCS and sinonasal carcinomas with neuroendocrine/neuroectodermal differentiation. However, while SMARCA4 and β-catenin immunohistochemistry may help confirm a challenging diagnosis, TCS should not be regarded as a molecularly defined entity

Limited sinonasal Rosai-Dorfman disease presenting as chronic sinusitis

The sinonasal tract is a common extranodal site for Rosai-Dorfman disease (RDD). Recently, histiocytes with features of RDD were identified in the clinical setting of chronic sinusitis. This study evaluates whether this phenomenon should be considered part of the RDD spectrum or classified separately as RDD-like histiocytes. We prospectively collected 13 cases showing histological features of RDD in chronic sinusitis patients and identified 14 with similar findings (3.5%) via retrospective review of 403 sinus contents over 2 years. All 27 cases displayed nodular aggregates of eosinophilic histiocytes with intermixed lymphoplasmacytic inflammation, prominent eosinophils and emperipolesis. The histiocytes were positive for S100 protein and cyclin D1 and negative for CD1a and CD207. All patients presented with severe chronic sinusitis without tumour formation or systemic symptoms. Twelve patients with follow-up (55%) required repeat sinus surgery compared with just 43 other sinusitis patients evaluated (11%); features of RDD were present in their additional specimens. Two cases that underwent targeted next-generation sequencing (20%) had oncogenic mutations in NF1 and KEAP1. Overall, these findings confirm diagnostic histological and immunohistochemical features of RDD in a subset of chronic sinusitis specimens. While patients uniformly lack systemic involvement or tumefactive growth, they have a high risk of recurrent sinus disease. Although the relatively subtle nature of the findings raises consideration of separate classification, the presence of occasional oncogenic mutations and evidence of consistent MAPK/ERK pathway activation via cyclin D1 positivity suggests that this phenomenon represents a unique limited manifestation of RDD

Oral Human Papillomavirus Infection and Head and Neck Squamous Cell Carcinoma in Rural Northwest Cameroon

Objective Oral human papillomavirus (HPV) infection is the precursor for a growing subset of oropharyngeal squamous cell carcinomas (OPSCCs) in the developed world. This study was designed to characterize oral HPV infection and OPSCC in a region with high rates of HPV-driven cervical cancer. Study Design Cross-sectional cohort study, retrospective case series. Setting Northwest Cameroon referral hospital. Subjects and Methods Individuals infected with human immunodeficiency virus attending an outpatient clinic were evaluated for oral HPV infection with oral swabs or rinses that were tested for 51 HPV types. HNSCCs diagnosed and/or treated at the same hospital from 2011 to 2017 were retrospectively reviewed to ascertain demographic and tumor characteristics, and available OPSCCs were tested for HPV. Results The oral HPV infection study population comprised 101 participants. Most (69%) were female and never-smokers (84%). Participants had median 4 lifetime sexual partners (interquartile range, 3-7; range, 1-100). Five participants (5%) had oral HPV infection; one had 2 HPV types. HPV types detected were HPV68 (n = 2), HPV82 (n = 2), HPV32 (n = 1), and unknown (n = 1). No significant demographic or behavioral differences were detected among individuals with vs without oral HPV infection. OPSCCs comprised just 8% (n = 11) of 131 HNSCCs in the retrospective study population. Two of 7 OPSCCs were HPV positive. Conclusion The low prevalence of OPSCC observed in northwest Cameroon together with the rarity of oral HPV infection suggests low rates of HPV-driven oropharyngeal carcinogenesis in the region. Future research should examine how geographic differences in oral HPV infection are influenced by cultural norms and affect HPV-OPSCC epidemiology

Microcribriform Adenocarcinoma of Salivary Glands: A Unique Tumor Entity Characterized by an SS18::ZBTB7A Fusion

The landscape of salivary gland carcinomas is ever-changing, with a growing list of new tumors and newly elucidated variants of well-known tumor entities. The routine use of next-generation sequencing has been instrumental in identifying novel fusions and tumor entities, which has helped bring the classification to a more objective and evidenced-based model. However, morphology remains critical in assessing the validity of these novel molecular findings, and most importantly, in assessing which of these findings will have an impact on the prognosis and treatment decisions for patients. The recognition of microsecretory adenocarcinoma (MSA) as a distinct low-grade malignancy of salivary glands, underpinned by MEF2C::SS18, and a single possibly related case of SS18::ZBTB7A, recently expanded this growing list of distinctive tumors. It was not until now, however, that the morphology of the latter case was known to be unique and reproducible. The authors have now seen 4 of these distinctive tumors that show a combination of distinctive oncocytic cells forming compact glandular growth as well as amphophilic cells forming tubular growth, and suggest the appellation "microcribriform adenocarcinoma" (MCA). So far, these tumors appear to preferentially occur in nonoral sites (2 parotid, 1 submandibular gland, and 1 bronchial seromucous glands). By immunohistochemistry, they express S100 and SOX-10 with focal outer myoepithelial cells marked by circumferential p63, p40, and smooth muscle actin staining around some of the nests and tubules. The tumors show infiltrative growth within a hyalinized and myxoid stroma. Cytologically, they appear generally low grade, similar to MSA. The morphologic and molecular uniformity of these 4 microcribriform adenocarcinoma cases warrants their recognition, and while related to MSA, they are sufficiently different to be classified as a distinct tumor. So far, in limited follow-up, these tumors appear to be relatively indolent

Mesenchymal Chondrosarcoma of the Head and Neck with HEY1::NCOA2 Fusion:a Clinicopathologic and Molecular Study of 13 Cases with Emphasis on Diagnostic Pitfalls

BACKGROUND: Mesenchymal chondrosarcoma (MCS) is a rare translocation-associated sarcoma, driven by a canonical HEY1::NCOA2 fusion. The tumors typically have a biphasic phenotype of primitive small blue round cells intermixed with hyaline cartilage. The head and neck (HN) region is a common site for MCS, accounting for 12-45% of all MCSs reported. AIMS: We assembled a relatively large cohort of 13 molecularly confirmed HN MCS for a detailed clinicopathologic analysis. The underlying fusion events were determined using fluorescence in situ hybridization and/or targeted RNA sequencing. RESULTS: The median age of presentation was 19 years. Five MCSs (39%) had an intraosseous presentation (skull, maxilla, palate, and mandible), while the remaining 8 cases occurred in the brain/meninges, orbit, and nasal cavity. Microscopically, HN MCSs were characterized by primitive round cells arranged in a distinctive nested architecture and a rich staghorn vasculature. A cartilaginous component of hyaline cartilage islands and/or single chondrocytes were present in 69% cases. A combined immunoprofile of CD99(+)/SATB2(+)/CD34(-)/STAT6(-) was typically noted. As this immunoprofile is non-specific, the referral diagnoses in cases lacking a cartilaginous component included Ewing sarcoma family and osteosarcoma. Among the 7 patients with follow-up data, three developed distant metastasis and one died of disease. CONCLUSION: HN MCS may arise at intra- or extra-osseous sites. The HN MCS appears to have a more prolonged survival compared other MCS sites. Testing for HEY1::NCOA2 fusion is recommended in HN tumors with nested round cell morphology and staghorn vasculature that lack a distinctive cartilaginous component. This article is protected by copyright. All rights reserved

Recurrent Wnt Pathway and ARID1A alterations in sinonasal olfactory carcinoma

Sinonasal tumors with neuroepithelial differentiation, defined by neuroectodermal elements reminiscent of olfactory neuroblastoma (ONB) and epithelial features such as keratin expression or gland formation, are a diagnostically challenging group that has never been formally included in sinonasal tumor classifications. Recently, we documented that most of these neuroepithelial neoplasms have distinctive histologic and immunohistochemical findings and proposed the term olfactory carcinoma to describe these tumors. However, the molecular characteristics of olfactory carcinoma have not yet been evaluated. In this study, we performed targeted molecular profiling of 23 sinonasal olfactory carcinomas to further clarify their pathogenesis and classification. All tumors included in this study were composed of high-grade neuroectodermal cells that were positive for pankeratin and at least 1 specific neuroendocrine marker. A significant subset of cases also displayed rosettes and neurofibrillary matrix, intermixed glands with variable cilia, peripheral p63/p40 expression, and S100 protein-positive sustentacular cells. Recurrent oncogenic molecular alterations were identified in 20 tumors, including Wnt pathway alterations affecting CTNNB1 (n = 8) and PPP2R1A (n = 2), ARID1A inactivation (n = 5), RUNX1 mutations (n = 3), and IDH2 hotspot mutations (n = 2). Overall, these findings do demonstrate the presence of recurrent molecular alterations in olfactory carcinoma, although this group of tumors does not appear to be defined by any single mutation. Minimal overlap with alterations previously reported in ONB also adds to histologic and immunohistochemical separation between ONB and olfactory carcinoma. Conversely, these molecular findings enhance the overlap between olfactory carcinoma and sinonasal neuroendocrine carcinomas. A small subset of neuroepithelial tumors might better fit into the superseding molecular category of IDH2-mutant sinonasal carcinoma. At this point, sinonasal neuroendocrine and neuroepithelial tumors may best be regarded as a histologic and molecular spectrum that includes core groups of ONB, olfactory carcinoma, neuroendocrine carcinoma, and IDH2-mutant sinonasal carcinoma