The pathology of reactive, dysplastic, and neoplastic sinonasal seromucinous glands is complex, and their contribution to tumorigenesis of sinonasal carcinomas remains controversial. In our practice, we have observed the presence of respiratory epithelial adenomatoid hamartomas (REAH) and seromucinous hamartomas (SH) associated with adenoid cystic carcinomas (AdCC) in a subset of cases. In many of these cases, genuine atypical features and dysplastic characteristics of the glands were noted at the interface of SH and AdCC. To investigate this phenomenon further, 88 sinonasal AdCC cases were selected from the authors' files and analyzed histologically, immunohistochemically, and genetically searching for MYB/MYBL1 and NFIB gene fusions. HPV testing was also performed. Univariate statistical analysis was conducted on our cohort. Thirty-one cases (35%) showed features of atypical sinonasal glands arising in SH (ASGSH) at the SH-AdCC interface, characterized by bilayered epithelium, architectural disarray, mild nuclear polymorphism, and atypia, sometimes with colloid-like material in the lumen. The MYB immunomarker was negative in 14 ASGSHs (with a positive internal control in AdCC cells), while only two cases showed faint and moderate to weak expression of the antibody in ASGSH glands. In 12 cases, the immunostaining of ASGSH could not be properly assessed, while AdCC cells were negative. The immunostaining was not performed in five cases. Our findings suggest that a subset of sinonasal AdCC may originate in a multistep dysplastic process within SH, consistent with an SH-ASGSH-AdCC progression sequence.

• Klíčová slova
• Adenoid cystic carcinoma, Atypical sinonasal glands arising in seromucinous hamartoma, MYB, MYBL1, NFIB, Respiratory epithelial adenomatoid hamartoma, Seromucinous hamartoma,
• MeSH
• adenoidně cystický karcinom * patologie   genetika   chemie   MeSH
• dospělí MeSH
• hamartom * patologie   genetika   MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery analýza   genetika   MeSH
• nádory vedlejších dutin nosních * patologie   genetika   MeSH
• protoonkogenní proteiny c-myb genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• MYB protein, human MeSH Prohlížeč
• nádorové biomarkery MeSH
• protoonkogenní proteiny c-myb MeSH

Adenoid cystic carcinomas (AdCC) of salivary gland origin have long been categorized as fusion-defined carcinomas owing to the almost universal presence of the gene fusion MYB::NFIB , or less commonly MYBL1::NFIB. Sinonasal AdCC is an aggressive salivary gland malignancy with no effective systemic therapy. Therefore, it is urgent to search for potentially targetable genetic alterations associated with AdCC. We have searched the authors' registries and selected all AdCCs arising in the sinonasal tract. The tumors were examined histologically, immunohistochemically, by next generation sequencing (NGS) and/or fluorescence in situ hybridization (FISH) looking for MYB/MYBL1 and/or NFIB gene fusions or any novel gene fusions and/or mutations. In addition, all tumors were tested for HPV by genotyping using (q)PCR. Our cohort comprised 88 cases of sinonasal AdCC, predominantly characterized by canonical MYB::NFIB (49 cases) and MYBL1::NFIB (9 cases) fusions. In addition, noncanonical fusions EWSR1::MYB ; ACTB::MYB; ESRRG::DNM3 , and ACTN4::MYB were identified by NGS, each of them in 1 case. Among nine fusion-negative AdCCs, FISH detected rearrangements in MYB (7 cases) , NFIB (1 case), and EWSR1 (1 case). Six AdCCs lacked fusions or gene rearrangements, while 11 cases were unanalyzable. Mutational analysis was performed by NGS in 31/88 (35%) AdCCs. Mutations in genes with established roles in oncogenesis were identified in 21/31 tumors (68%), including BCOR (4/21; 19%), NOTCH1 (3/21; 14%), EP300 (3/21; 14%), SMARCA4 (2/21; 9%), RUNX1 (2/21; 9%), KDM6A (2/21; 9%), SPEN (2/21; 9%), and RIT1, MGA, RB1, PHF6, PTEN, CREBBP, DDX41, CHD2, ROS1, TAF1, CCD1, NF1, PALB2, AVCR1B, ARID1A, PPM1D, LZTR1, GEN1 , PDGFRA , each in 1 case (1/21; 5%). Additional 24 cases exhibited a spectrum of gene mutations of uncertain pathogenetic significance. No morphologic differences were observed between AdCCs with MYBL1::NFIB and MYB::NFIB fusions. Interestingly, mutations in the NOTCH genes were seen in connection with both canonical and noncanonical fusions, and often associated with high-grade histology or metatypical phenotype, as well as with poorer clinical outcome. Noncanonical fusions were predominantly observed in metatypical AdCCs. These findings emphasize the value of comprehensive molecular profiling in correlating morphologic characteristics, genetic landscape, and clinical behavior in AdCC.

• MeSH
• adenoidně cystický karcinom * genetika   patologie   chemie   MeSH
• dospělí MeSH
• fenotyp MeSH
• fúze genů * MeSH
• fúzní onkogenní proteiny * genetika   MeSH
• genetická predispozice k nemoci MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mutace * MeSH
• mutační analýza DNA MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory vedlejších dutin nosních * genetika   patologie   chemie   MeSH
• protoonkogenní proteiny MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• stanovení celkové genové exprese MeSH
• trans-aktivátory genetika   MeSH
• transkripční faktory NFI genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fúzní onkogenní proteiny * MeSH
• MYBL1 protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• NFIB protein, human MeSH Prohlížeč
• protoonkogenní proteiny MeSH
• trans-aktivátory MeSH
• transkripční faktory NFI MeSH

AIMS: Sinonasal adenosquamous carcinoma (ASC) is a rare tumour classified as a variant of squamous cell carcinoma, exhibiting both squamous and glandular differentiation. ASC has a poorer prognosis compared to sinonasal mucoepidermoid carcinoma (MEC), another uncommon tumour in this region. ASC is believed to originate from metaplastic squamous epithelium, though it may also arise from respiratory epithelium in respiratory epithelial adenomatoid hamartoma (REAH) or seromucinous glands in seromucinous hamartoma (SH). METHODS AND RESULTS: Five cases of sinonasal ASC were retrieved from our registry. Initially, they were classified as sinonasal MEC (n = 3), ASC (n = 2), and carcinoma ex REAH (n = 1). All cases showed adenosquamous malignant proliferation beneath the surface respiratory epithelium with occasional squamous metaplasia, except for one case that showed dysplasia. The respiratory epithelium exhibited an inverted growth pattern consistent with REAH/SH, and displayed atypical sinonasal glands (ASGSH) arising within seromucinous hamartoma. Next-generation sequencing (NGS) revealed multiple pathogenic mutations in two cases, and in case 4 GGA2::PRKCB and EYA2::SERINC3 gene fusions. One case was positive for high-risk HPV. None of the cases exhibited CRTC1/3::MAML2 gene fusion. CONCLUSION: The connection between ASGSH and ASC has not been described in the literature. There is a growing need for additional studies on the morphological, immunohistochemical, and genetic aspects of these tumours. SH/REAH may serve as precursor lesions in the progression of atypical sinonasal glands to malignancy, and their role in tumour development deserves further investigation.

• Klíčová slova
• EYA2, GGA2, PRKCB, SERINC3, HPV, adenosquamous carcinoma, genetic, mucoepidermoid carcinoma,
• MeSH
• adenoskvamózní karcinom * patologie   genetika   MeSH
• dospělí MeSH
• hamartom * patologie   genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory vedlejších dutin nosních * patologie   genetika   MeSH
• respirační sliznice patologie   MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH