Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-02-16DOI: 10.1007/s12105-021-01299-4
Costantino Ricci, Federico Chiarucci, Francesca Ambrosi, Tiziana Balbi, Barbara Corti, Ottavio Piccin, Ernesto Pasquini, Maria Pia Foschini
{"title":"Co-expression of Myoepithelial and Melanocytic Features in Carcinoma Ex Pleomorphic Adenoma.","authors":"Costantino Ricci, Federico Chiarucci, Francesca Ambrosi, Tiziana Balbi, Barbara Corti, Ottavio Piccin, Ernesto Pasquini, Maria Pia Foschini","doi":"10.1007/s12105-021-01299-4","DOIUrl":"https://doi.org/10.1007/s12105-021-01299-4","url":null,"abstract":"<p><p>The presence of melanin pigment and melanocytic markers expression have been rarely reported in salivary gland tumors. Herein, two cases of carcinoma arising in pleomorphic adenoma of the parotid gland and showing diffuse expression of myoepithelial and melanocytic markers are described. The clinical-pathological clues useful in the differential diagnosis with melanoma are discussed. In addition, a review of the pertinent literature is also proposed, discussing the pathologic mechanisms potentially involved in this phenomenon.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1385-1390"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01299-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25373571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-02-22DOI: 10.1007/s12105-021-01305-9
Amy S Duffield, Jonathan Webster, B Douglas Smith, Julius S Necciai, Austin McCuiston, Alisha D Ware
{"title":"Myeloid Neoplasm with PDGFRA Rearrangement Manifesting as a Retromolar Pad Mass.","authors":"Amy S Duffield, Jonathan Webster, B Douglas Smith, Julius S Necciai, Austin McCuiston, Alisha D Ware","doi":"10.1007/s12105-021-01305-9","DOIUrl":"https://doi.org/10.1007/s12105-021-01305-9","url":null,"abstract":"<p><p>Myeloid neoplasms with PDGFRA rearrangement are rare, and most commonly present with features of chronic eosinophilic leukemia; however, they rarely manifest as acute myeloid or lymphoblastic leukemia. Patients typically present with symptoms of hypereosinophilia including cardiovascular and pulmonary symptoms. An increase in mast cells is also a common feature of this disease, and there may be elevated serum tryptase with significant clinical overlap with systemic mastocytosis. Here, we present an unusual case of a myeloid neoplasm with PDGFRA rearrangement manifesting as a retromolar pad mass in a patient with a prior diagnosis of systemic mastocytosis. This case highlights the possibility of soft tissue involvement by myeloid neoplasms with PDGFRA rearrangement in the oral cavity. The identification of this entity is of significant clinical importance because many patients can be effectively treated with tyrosine kinase inhibitors.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1399-1403"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01305-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25393218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-01-18DOI: 10.1007/s12105-021-01285-w
Derek Tsz Wai Yau, Shun Wong, Chit Chow, Ka Fai To
{"title":"Round Cell Sarcoma with EWSR1-PATZ1 Fusion in the Face of a Five-Year-Old Boy: Report of a Case with Unusual Histologic Features.","authors":"Derek Tsz Wai Yau, Shun Wong, Chit Chow, Ka Fai To","doi":"10.1007/s12105-021-01285-w","DOIUrl":"https://doi.org/10.1007/s12105-021-01285-w","url":null,"abstract":"<p><p>Round cell sarcomas with EWSR1-PATZ1 fusion are rare polyphenotypic sarcomas that typically show both neural and myogenic differentiation on immunohistochemistry. The histology features lobular admixture of cellular fascicles of relatively monotonous spindle cells and small blue round cells separated by fibrotic stroma. The clinical behavior of EWSR1-PATZ1 sarcoma is uncertain currently with mixed outcomes reported even in cases with metastases. We herein report an additional case of EWSR1-PATZ1 fusion-related round cell sarcoma in the face of a 5-year-old boy with unusual histologic features of pale zones, rosette/gland-like structures and expression of epithelial markers. Fluorescent in-situ hybridization study (FISH) using EWSR1 breakapart probes was negative and molecular study with RNA sequencing was required to confirm the diagnosis. These findings highlight the diagnostic challenge and potential pitfall of FISH study in EWSR1-PATZ1 sarcoma. Further studies are required to increase the understanding of their behavior, morphologic spectrum and molecular features that will help devise new treatment strategies to these rare tumours.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1350-1358"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01285-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38764938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-04-22DOI: 10.1007/s12105-021-01325-5
Philipp Wolber, Lisa Nachtsheim, Franziska Hoffmann, Jens Peter Klußmann, Moritz Meyer, Ferdinand von Eggeling, Orlando Guntinas-Lichius, Alexander Quaas, Christoph Arolt
{"title":"Trophoblast Cell Surface Antigen 2 (Trop-2) Protein is Highly Expressed in Salivary Gland Carcinomas and Represents a Potential Therapeutic Target.","authors":"Philipp Wolber, Lisa Nachtsheim, Franziska Hoffmann, Jens Peter Klußmann, Moritz Meyer, Ferdinand von Eggeling, Orlando Guntinas-Lichius, Alexander Quaas, Christoph Arolt","doi":"10.1007/s12105-021-01325-5","DOIUrl":"https://doi.org/10.1007/s12105-021-01325-5","url":null,"abstract":"<p><p>Treatment options for unresectable, recurrent or metastatic salivary gland carcinomas (SGC) are scarce. Trophoblast cell surface antigen 2 (Trop-2) is a transmembrane glycoprotein that is involved in a variety of oncogenic cell signaling pathways. Its potential as a target for the antibody-drug conjugate sacituzumab govitecan has already been demonstrated in different tumor entities. The United States Food and Drug Administration approved this antibody-drug conjugate for the treatment of metastatic triple-negative breast cancer. Here, we aimed to investigate Trop-2 protein expression in different entities of SGCs. We retrospectively reviewed the medical records of all patients that underwent surgery for a primary SGC in a tertiary referral center between 1990 and 2014. Immunohistochemical (IHC) staining for Trop-2 was performed and rated as negative, weak, moderate or high using a semiquantitative score. Additionally, representative cases were analyzed using MALDI-mass spectrometry (MS) imaging to confirm the IHC results. The cohort consisted of 114 tumors of the parotid gland (90.4%) and submandibular gland (9.6%). It mainly included mucoepidermoid, salivary duct and adenoid cystic carcinomas. In IHC samples, 44% showed high, 38% moderate and 10% weak expression rates of Trop-2. MALDI-MS imaging confirmed the presence of Trop-2 protein in 80% of the tested tumor samples. This is the first study to demonstrate that several types of SGC express Trop-2 with variable intensity. Since there are currently few systemic treatment options for advanced SGCs, Trop-2 represents a promising target for further clinical studies, for instance, with sacituzumab govitecan.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1147-1155"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01325-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38897732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-04-11DOI: 10.1007/s12105-021-01319-3
Camila Matsunaga de Angelis, Reydson Alcides de Lima-Souza, João Figueira Scarini, Erika Said Abu Egal, Gleyson Kleber do Amaral-Silva, Rogério de Oliveira Gondak, Oslei Paes de Almeida, Carlos Takahiro Chone, Luiz Paulo Kowalski, Albina Altemani, Fernanda Viviane Mariano
{"title":"Immunohistochemical Expression of Fatty Acid Synthase (FASN) is Correlated to Tumor Aggressiveness and Cellular Differentiation in Salivary Gland Carcinomas.","authors":"Camila Matsunaga de Angelis, Reydson Alcides de Lima-Souza, João Figueira Scarini, Erika Said Abu Egal, Gleyson Kleber do Amaral-Silva, Rogério de Oliveira Gondak, Oslei Paes de Almeida, Carlos Takahiro Chone, Luiz Paulo Kowalski, Albina Altemani, Fernanda Viviane Mariano","doi":"10.1007/s12105-021-01319-3","DOIUrl":"https://doi.org/10.1007/s12105-021-01319-3","url":null,"abstract":"<p><p>Fatty acid synthase (FASN) expression is closely related to cancer progression, in particular, tumor aggressiveness and poor prognosis. This study aimed to analyse the expression of FASN in carcinomas of the salivary glands and correlate it with Ki-67 expression. We analysed by immunohistochemistry the expression of FASN and Ki-67 on tissue sections from 7 cases of adenocarcinoma, not otherwise specified (AdNOS), 6 cases of polymorphous adenocarcinoma (PAC), 16 cases of acinic cell carcinoma (AcCC), 19 cases of adenoid cystic carcinoma (AdCC), 15 cases of epithelial-myoepithelial carcinoma (EMC); 10 cases of secretory carcinoma (SC), 13 cases of mucoepidermoid carcinoma (MEC), 10 cases of salivary duct carcinoma (SDC) and 7 cases of myoepithelial carcinoma (MC). These carcinomas were classified into aggressive and indolent regarding their biological behaviour. Additionally, MEC and AdCC were also classified according to the histological grade. High expression of FASN was found in SDC (100%), SC (100%), AcCC (68.7%) and AdNOS (57.2%). No association was found between FASN and Ki-67 expression. Aggressive carcinomas showed a higher rate of Ki-67 proliferation (p < 0.001) and greater expression of FASN when compared to indolent carcinomas (p < 0.05). With regards to carcinomas categorized as indolent, FASN expression was much higher in the lesions that presented cell differentiation (SC and AcCC). Also, FASN expression was significantly higher in high-grade AdCC and MEC when compared to low-grade tumors (p < 0.05). We concluded that FASN expression was correlated to tumor aggressiveness and cellular differentiation in salivary gland carcinomas.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1119-1126"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01319-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25591793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Myoepithelial Carcinoma Ex Pleomorphic Adenoma of the Maxillary Sinus: A Case Report and Review of Literature.","authors":"Giovacchini Francesco, Caselli Emanuele, Monarchi Gabriele, Mitro Valeria, Sidoni Angelo, Tullio Antonio","doi":"10.1007/s12105-020-01282-5","DOIUrl":"https://doi.org/10.1007/s12105-020-01282-5","url":null,"abstract":"<p><p>Myoepithelial carcinoma ex pleomorphic adenoma is defined as a malignant epithelial neoplasm arising from a primary or recurrent benign pleomorphic adenoma. This type of tumor comprises 3.6% of all salivary gland tumors and 12% of malignant ones. Clinically, it most commonly presents as a firm mass in the parotid gland. The development of this neoplasm in the sinonasal and nasopharyngeal regions is extremely rare and only few cases are reported in the literature. The prognosis of myoepithelial carcinoma is variable. Marked cellular pleomorphism, high mitotic rate, and high proliferative activity correspond to a poor prognosis. In this article, the authors report the histopathological features of a clinical case of a 64-years-old patient with a large median maxillary neoplasm diagnosed as myoepithelial carcinoma/ex-pleomorphic adenoma. The tumor was resected and subjected to secondary reconstruction using a revascularized free fibula flap. The myoepithelial derivation of neoplastic cells was demonstrated by immunohistochemical positivity for S-100 protein (strong and diffuse), cytokeratin 14 (strong and diffuse), and GFAP (focal).</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1345-1349"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-020-01282-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38777558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-01-04DOI: 10.1007/s12105-020-01276-3
Ahitagni Biswas, Sorun Shishak, Swarnaditya Roy, Aanchal Kakkar
{"title":"Combined Modality Management of Sinonasal Anaplastic Lymphoma Kinase Negative Anaplastic Large Cell Lymphoma in a Geriatric Patient-Report of a Rare Case.","authors":"Ahitagni Biswas, Sorun Shishak, Swarnaditya Roy, Aanchal Kakkar","doi":"10.1007/s12105-020-01276-3","DOIUrl":"https://doi.org/10.1007/s12105-020-01276-3","url":null,"abstract":"<p><p>Sinonasal anaplastic lymphoma kinase(ALK)-negative anaplastic large cell lymphoma(ALCL) without nodal involvement is exceedingly rare and the rarity of this tumor often engenders diagnostic dilemma. It has been mostly reported in pediatric, adolescent and young adult patients, mostly of Asian origin. A 70-year-old female patient presented with a mass in the left nasal cavity causing nasal obstruction for 5 months. On clinical and radiological examination, there was a 5.7 cm mass in the left nasal cavity, completely obliterating the left ethmoid sinus. Biopsy from the nasal mass showed a poorly differentiated malignant tumour with large cells arranged in sheets. On immunohistochemistry, the tumour cells were positive for leukocyte common antigen(LCA), CD30, CD43, BCL6 and focally for CD5, TIA1, granzyme B and epithelial membrane antigen(EMA), and were negative for CD56, EBV-LMP1, CD79a, PAX5, myeloperoxidase, CD34, CD7, CD4, CD8, CD138, ALK and p63, suggestive of ALK-negative ALCL. Rest of the lymphoma work-up was essentially normal and she had stage IE disease. She was treated with prephase chemotherapy (Vincristine and Prednisolone) followed by 4 cycles of CEOP[Cyclophosphamide, Etoposide (from 2nd cycle onwards), Vincristine and Prednisolone] regimen and local radiotherapy (36 Gy/20 fractions/4 weeks) by intensity modulated radiotherapy(IMRT) technique resulting in complete clinical and radiological response. At last follow-up visit, 15 months from the initial diagnosis, she was alive and disease free. Sinonasal ALK-negative ALCL is a rare tumor which can be effectively treated with a combination of multi-agent CHOP/CHOP-like regimen and local conformal radiotherapy in geriatric patients.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1335-1344"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-020-01276-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38782577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-03-11DOI: 10.1007/s12105-021-01312-w
Liam Robinson, Ciska-Mari Schouwstra, Willie F P van Heerden
{"title":"Oropharyngeal Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN): A Case Report and Literature Review.","authors":"Liam Robinson, Ciska-Mari Schouwstra, Willie F P van Heerden","doi":"10.1007/s12105-021-01312-w","DOIUrl":"https://doi.org/10.1007/s12105-021-01312-w","url":null,"abstract":"<p><p>Primary mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) of the head and neck region is a rare biphasic tumor with an aggressive biological behavior. This report highlights an additional case of oropharyngeal MiNEN in a 46-year-old male patient with a previous long-term smoking history. Histologic evaluation revealed a biphasic tumor infiltrating the lamina propria. The first component consisted of a classic keratinizing squamous cell carcinoma. The second component consisted of small-to-intermediate sized cells with neuroendocrine features. Synaptophysin and CD56 immunohistochemical stains confirmed neuroendocrine lineage in this component. The presence of two morphological components with neuroendocrine and nonneuroendocrine features on histologic assessment should alert the pathologist to consider a MiNEN in their case work-up.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1415-1420"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01312-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25479836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-02-27DOI: 10.1007/s12105-021-01303-x
Zahra Aldawood, David J Moyer, Sook-Bin Woo
{"title":"A Bronchogenic Cyst Masquerading as a Tongue Mass.","authors":"Zahra Aldawood, David J Moyer, Sook-Bin Woo","doi":"10.1007/s12105-021-01303-x","DOIUrl":"https://doi.org/10.1007/s12105-021-01303-x","url":null,"abstract":"<p><p>Bronchogenic cysts are foregut-derived developmental anomalies found along the developmental pathway of the foregut. The putative theory of pathogenesis is abnormal budding or branching of epithelial cells during the development of tracheobronchial tree. Over 99 % of cases occur in the mediastinum and lung while the head and neck area is affected in less than 1 % of cases with only rare cases reported in the oral cavity. This is a report of a case of a bronchogenic cyst arising in a 6-year-old male. The lesion presented as a painless swelling of the left underside of the tongue. Microscopically, the cyst was lined by pseudostratified columnar epithelium exhibiting many ciliated and mucous cells. A focus of cartilage and discontinuous bundles of smooth muscle were present adjacent to the lining. Where there was cyst rupture, there was granulation tissue associated with many foamy macrophages and acute and chronic inflammation. Four other cases, three in the tongue and one in the lower lip vestibule with cutaneous extension, all in the midline, have been reported in a 1 day-old male, 4 year-old male, 6 year-old female and 3 year-old male. There was no recurrence after excision and this is in keeping with the behavior in previous reports. Other developmental cysts including foregut cysts may be focally lined with respiratory epithelium but the presence of cartilage is the sine qua non for the diagnosis of a bronchogenic cyst.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1404-1408"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01303-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25409848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head and neck pathologyPub Date : 2021-12-01Epub Date: 2021-05-31DOI: 10.1007/s12105-021-01338-0
Zhonghua Liu, Mukund Seshadri, Vishal Gupta, Antonios Papanicolau-Sengos, Mihai Merzianu
{"title":"INI1-Deficient Thyroid Carcinoma is an Aggressive Disease with Epithelioid and Rhabdoid Phenotype. A Case Report, Survey of INI1 Expression in Thyroid Lesions and Literature Review.","authors":"Zhonghua Liu, Mukund Seshadri, Vishal Gupta, Antonios Papanicolau-Sengos, Mihai Merzianu","doi":"10.1007/s12105-021-01338-0","DOIUrl":"https://doi.org/10.1007/s12105-021-01338-0","url":null,"abstract":"<p><p>Integrase interactor 1 (INI1)-deficient carcinomas, recently described in several sites including the head and neck, are associated with basaloid or rhabdoid histology and aggressive behavior irrespective of origin. INI1-deficient thyroid carcinoma is extremely rare. We present here the phenotype and genotype of an INI1-deficient thyroid carcinoma and report on the INI1 protein expression in various thyroid lesions. Case report with clinicopathologic and molecular characterization and INI1 assessment in 184 thyroid lesions. A 67-year-old woman presented with globus sensation due to a large thyroid mass with extrathyroid extension, focal necrosis and cervical and mediastinal nodal involvement. Histologically, tumor cells had a solid, alveolar and pseudopapillary architecture in a myxoid stroma, exhibited monomorphic epithelioid and focal rhabdoid/plasmacytoid morphology and lacked glandular, squamous or follicular cell differentiation. Tumor cells were positive for AE1/AE3 and CK18 but negative for TTF1, thyroglobulin and PAX8. INI1 nuclear expression was absent. A frameshift SMARCB1/INI1 mutation was detected. In addition, TET2 and Notch1 mutations were present but alterations of BRAF, RET, PAX8/PPAR8 or RAS were not identified. Patient death occurred 14 months after diagnosis from post-therapeutic complications. None of the 184 benign and malignant thyroid lesions tested, including 12 poorly and undifferentiated thyroid carcinomas, were INI1-deficient. INI1-deficient thyroid carcinoma shares the phenotype, genotype and biology of other INI1-deficient tumors. Epithelioid and plasmacytoid/rhabdoid changes are most frequent whereas basaloid morphology is not reported, in contrast with sinonasal tumors. Poorly differentiated and undifferentiated thyroid tumors with epithelioid or rhabdoid morphology should be tested for INI1 protein expression to better characterize these aggressive neoplasms and identify patients eligible for targeted therapy.</p>","PeriodicalId":520636,"journal":{"name":"Head and neck pathology","volume":" ","pages":"1246-1252"},"PeriodicalIF":2.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12105-021-01338-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39051377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}