SMARCB1-deficient sinonasal adenocarcinoma is a rare variant of SWI/SNF-deficient malignancies with SMARCB1 loss and adenocarcinoma features. More than 200 high-grade epithelial sinonasal malignancies were retrieved. A total of 14 cases exhibited complete SMARCB1 (INI1) loss and glandular differentiation. SMARCA2 and SMARCA4 were normal, except for one case with a loss of SMARCA2. Next-generation sequencing (NGS) and/or fluorescence in situ hybridization (FISH) revealed an alteration in the SMARCB1 gene in 9/13 cases, while 2/13 were negative. Two tumors harbored SMARCB1 mutations in c.157C > T p.(Arg53Ter) and c.842G > A p.(Trp281Ter). One harbored ARID1B mutations in c.1469G > A p.(Trp490Ter) and MGA c.3724C > T p.(Arg1242Ter). Seven tumors had a SMARCB1 deletion. One carried an ESR1 mutation in c.644-2A > T, and another carried a POLE mutation in c.352_374del p.(Ser118GlyfsTer78). One case had a PAX3 mutation in c.44del p.(Gly15AlafsTer95). Histomorphology of SMARCB1-deficient adenocarcinoma was oncocytoid/rhabdoid and glandular, solid, or trabecular in 9/14 cases. Two had basaloid/blue cytoplasm and one showed focal signet ring cells. Yolk sac tumor-like differentiation with Schiller-Duval-like bodies was seen in 6/14 cases, with 2 cases showing exclusively reticular-microcystic yolk sac pattern. Follow-up of a maximum of 26 months (median 10 months) was available for 8/14 patients. Distant metastasis to the lung, liver, mediastinum, bone, and/or retroperitoneum was seen in 4/8 cases. Locoregional failure was seen in 75% of patients, with 6/8 local recurrences and 3 cervical lymph node metastases. At the last follow-up, 5 of 8 (62%) patients had died of their disease 2 to 20 months after diagnosis (median 8.2 months), and 3 were alive with the disease. The original diagnosis was usually high-grade non-intestinal-type adenocarcinoma or high-grade myoepithelial carcinoma. A correct diagnosis of these aggressive tumors could lead to improved targeted therapies with potentially better overall disease-specific survival.

• Klíčová slova
• Head and neck, Next-generation sequencing, Rhabdoid, SMARCB1-deficient adenocarcinoma, SWI/SNF complex, Sinonasal, Yolk sac-like,
• MeSH
• adenokarcinom * genetika   patologie   MeSH
• diferenciální diagnóza MeSH
• DNA vazebné proteiny genetika   nedostatek   MeSH
• dospělí MeSH
• gen SMARCB1 * nedostatek   genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace * MeSH
• myoepiteliální nádor * genetika   patologie   MeSH
• nádorové biomarkery genetika   MeSH
• nádory vedlejších dutin nosních * genetika   patologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• stupeň nádoru MeSH
• transkripční faktory * genetika   nedostatek   MeSH
• vysoce účinné nukleotidové sekvenování 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
• DNA vazebné proteiny MeSH
• gen SMARCB1 * MeSH
• nádorové biomarkery MeSH
• SMARCB1 protein, human MeSH Prohlížeč
• transkripční faktory * MeSH

We report 2 cases of high-grade sinonasal adenocarcinoma with a distinct morphological and immunohistochemical phenotype. Albeit histologically different from secretory carcinoma of the salivary glands, both tumors presented here share an ETV6::NTRK3 fusion. The highly cellular tumors were composed of solid and dense cribriform nests, often with comedo-like necroses in the center, and minor areas with papillary, microcystic, and trabecular formations without secretions, mostly located at the periphery of the lesion. The cells displayed high-grade features, with enlarged, crowded, and often vesicular nuclei with conspicuous nucleoli and brisk mitotic activity. The tumor cells were immunonegative for mammaglobin while showing immunopositivity for p40/p63, S100, SOX10, and GATA3, as well as for cytokeratins 7, 18, and 19. For the first time, we describe 2 cases of primary high-grade non-intestinal type adenocarcinomas of the nasal cavity, distinct from secretory carcinoma by morphology and immunoprofile, harboring the ETV6::NTRK3 fusion.

• Klíčová slova
• ETV6::NTRK3, Nasal cavity, Salivary duct carcinoma, Secretory carcinoma, Sinonasal, non-intestinal-type adenocarcinoma,
• MeSH
• adenokarcinom * genetika   patologie   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• imunohistochemie MeSH
• karcinom * genetika   patologie   MeSH
• lidé MeSH
• nádorové biomarkery genetika   MeSH
• nádory prsu MeSH
• nádory slinných žláz * genetika   patologie   MeSH
• protein ETS, translokační varianta 6 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• fúzní onkogenní proteiny MeSH
• nádorové biomarkery MeSH
• NTRK3 protein, human MeSH Prohlížeč

We present a 72 years old male with a left nasal cavity (mammary analogue) secretory carcinoma (SC) which exhibited classical morphological features on light microscopical examination, diffuse strong S100 and mammoglobin positivity on immunohistochemistry, and ETV6-NTRK3 gene fusion on next generation sequencing (NGS) analysis. Unusual features of this tumor are expression of p63 and DOG1 on immunohistochemistry and the atypical junction between Exon 4 of the ETV6 gene and Exon 14 of the NTRK3 gene.

• Klíčová slova
• ETV6-NTRK3 fusion protein, human, Immunohistochemistry, Mammary analogue secretory carcinoma, Nasal cavity,
• MeSH
• anoctamin 1 biosyntéza   MeSH
• exony genetika   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• lidé MeSH
• membránové proteiny biosyntéza   MeSH
• nádorové biomarkery analýza   MeSH
• nádorové proteiny biosyntéza   MeSH
• nádory nosu genetika   patologie   MeSH
• nosní dutina patologie   MeSH
• sekreční karcinom mamárního typu genetika   patologie   MeSH
• sekvenční analýza DNA MeSH
• senioři MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• ANO1 protein, human MeSH Prohlížeč
• anoctamin 1 MeSH
• CKAP4 protein, human MeSH Prohlížeč
• ETV6-NTRK3 fusion protein, human MeSH Prohlížeč
• fúzní onkogenní proteiny MeSH
• membránové proteiny MeSH
• nádorové biomarkery MeSH
• nádorové proteiny MeSH