This review focuses on the heterogenous group of clear cell neoplasms of salivary glands and attempts to identify major differential diagnostic features. Within the head and neck region, clear cells are found most commonly in salivary gland tumors, but may also be seen in tumors of squamous or odontogenic epithelial origin, primary or metastatic carcinomas, benign or malignant melanocytic lesions, or benign or malignant mesenchymal tumors. Clear cells occur fairly commonly among a wide variety of salivary gland neoplasms, but mostly they constitute only a minor component of the tumor cell population. Clear cells represent a major diagnostic feature in two salivary gland neoplasms, epithelial-myoepithelial carcinoma and hyalinizing clear cell carcinoma. In addition, salivary gland neoplasms composed predominantly of clear cells could also include clear cell variants of other salivary neoplasms, such as mucoepidermoid carcinoma and myoepithelial carcinoma, but their tumor type-specific histologic features may only be available in limited nonclear cell areas of the tumor. Diagnosing predominantly clear cell salivary gland tumors is difficult because the immunoprofiles and morphologic features may overlap and the same tumor entity may also have a wide range of other histologic presentations. Many salivary gland tumors are characterized by tumor type-specific genomic alterations, particularly gene fusions of the ETV6 gene in secretory carcinoma, the MYB and MYBL1 genes in adenoid cystic carcinoma, the MAML2 gene in mucoepidermoid carcinoma, the EWSR1 gene in hyalinizing clear cell carcinoma, and others. Thus, along with conventional histopathologic examination and immunoprofiling, molecular and genetic tests may be important in the diagnosis of salivary gland clear cell tumors by demonstrating genetic alterations specific to them.
- MeSH
- karcinom * patologie MeSH
- lidé MeSH
- mukoepidermoidní karcinom * diagnóza genetika patologie MeSH
- nádorové biomarkery genetika MeSH
- nádory slinných žláz * diagnóza genetika patologie MeSH
- slinné žlázy patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- nádorové biomarkery MeSH
Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and its diagnosis is straightforward in the majority of cases. However, not infrequently, PA shows unusual and uncommon histological features that can be confused with those of malignancy. The difficulties in diagnosing PA arise from its ability to mimic invasion, show atypical or metaplastic cytomorphology, and show morphological features that overlap with those of established salivary gland carcinomas. In addition, recognising early malignant transformation to carcinoma ex-pleomorphic adenoma continues to be a frequent challenge. This review describes the diagnostic pitfalls of PA, and offers a systematic approach to avoid them by combining classic histopathology with novel immunohistochemical and molecular tests.
- Klíčová slova
- MAML2, MYB, PLAG1, early carcinoma ex pleomorphic adenoma, invasion, oncocytic metaplasia, pleomorphic adenoma, squamous metaplasia,
- MeSH
- adenokarcinom diagnóza patologie MeSH
- diferenciální diagnóza * MeSH
- karcinom diagnóza patologie MeSH
- lidé MeSH
- metaplazie diagnóza patologie MeSH
- nádorová transformace buněk MeSH
- nádorové biomarkery analýza MeSH
- nádory slinných žláz diagnóza patologie MeSH
- pleomorfní adenom * diagnóza patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- nádorové biomarkery MeSH
High-grade transformation (HGT) or dedifferentiation has been described in a variety of salivary gland carcinomas, including acinic cell carcinoma, secretory carcinoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, polymorphous adenocarcinoma, low-grade mucoepidermoid carcinoma, and hyalinizing clear cell carcinoma. High-grade (HG) transformed tumors are composed of a conventional low-grade component characterized by specific microscopic and immunohistochemical features for the given entity, intermingled with or juxtaposed to areas of HG morphology. This is usually either poorly differentiated adenocarcinoma, carcinoma not otherwise specified, or undifferentiated carcinoma, in which the original line of differentiation is lost. The HG component is composed of solid nests of anaplastic cells with large vesicular pleomorphic nuclei, prominent nucleoli, and abundant cytoplasm. Frequent mitoses and extensive necrosis may be present. The Ki-67 labeling index is consistently higher in the HG component. The molecular genetic mechanisms responsible for HGT of salivary gland carcinomas are largely unknown, though p53 inactivation and human epidermal growth factor receptor 2 overexpression and/or gene amplification have been demonstrated in the HG component in a few examples, the frequency varies for each histologic type. Salivary gland carcinomas with HGT are more aggressive than conventional carcinomas, with a higher local recurrence rate and a poorer prognosis. They have a high propensity for cervical lymph node metastasis suggesting a need for a wider resection and neck dissection. HGT of salivary gland carcinoma can occur either at initial presentation or less commonly at the time of recurrence, sometimes following postoperative radiotherapy. The potential for HGT in almost any type of salivary gland carcinoma warrants a thorough sampling of all salivary gland malignancies to prevent oversight of a HG component.
- MeSH
- dediferenciace buněk fyziologie MeSH
- karcinom genetika patologie MeSH
- lidé MeSH
- nádorová transformace buněk genetika patologie MeSH
- nádorové biomarkery genetika MeSH
- nádory slinných žláz genetika patologie MeSH
- receptor erbB-2 genetika MeSH
- slinné žlázy patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- ERBB2 protein, human MeSH Prohlížeč
- nádorové biomarkery MeSH
- receptor erbB-2 MeSH
Since the first description of sinonasal undifferentiated carcinoma (SNUC) as a distinctive highly aggressive sinonasal neoplasm with probable origin from the sinonasal mucosa (Schneiderian epithelium), SNUC has been the subject of ongoing study and controversy. In particular, the SNUC category gradually became a "wastebasket" for any undifferentiated or unclassifiable sinonasal malignancy of definite or probable epithelial origin. However, with the availability of more specific and sensitive immunohistochemical antibodies and increasing implementation of novel genetic tools, the historical SNUC category became the subject of progressive subdivision leading to recognition of specific genetically defined, reproducible subtypes. These recently recognized entities are characterized by distinctive genetic aberrations including NUTM1-rearranged carcinoma (NUT carcinoma) and carcinomas associated with inactivation of different members of the SWI/SNF chromatin-remodeling gene complex such as SMARCB1-deficient and less frequently SMARCA4-deficient carcinoma. The ring became almost closed, with recent studies highlighting frequent oncogenic IDH2 mutations in the vast majority of histologically defined SNUCs, with a frequency of 82%. A review of these cases suggests the possibility that "true SNUC" probably represents a distinctive neoplastic disease entity, morphologically, phenotypically, and genetically. This review addresses this topic from a historical perspective, with a focus on recently recognized genetically defined subsets within the SNUC spectrum.
- MeSH
- DNA-helikasy genetika MeSH
- gen SMARCB1 genetika MeSH
- jaderné proteiny genetika MeSH
- karcinom diagnóza epidemiologie genetika MeSH
- lidé MeSH
- nádorové biomarkery genetika MeSH
- nádory sinu maxillaris diagnóza epidemiologie genetika MeSH
- transkripční faktory genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- DNA-helikasy MeSH
- gen SMARCB1 MeSH
- jaderné proteiny MeSH
- nádorové biomarkery MeSH
- SMARCA4 protein, human MeSH Prohlížeč
- SMARCB1 protein, human MeSH Prohlížeč
- transkripční faktory MeSH
Although relatively rare, polymorphous adenocarcinoma (PAC) is likely the second most common malignancy of the minor salivary glands (MiSG). The diagnosis is mainly based on an incisional biopsy. The optimal treatment comprises wide surgical excision, often with adjuvant radiotherapy. In general, PAC has a good prognosis. Previously, PAC was referred to as polymorphous low-grade adenocarcinoma (PLGA), but the new WHO classification of salivary gland tumours has also included under the PAC subheading, the so-called cribriform adenocarcinoma of minor salivary glands (CAMSG). This approach raised controversy, predominantly because of possible differences in clinical behaviour. For example, PLGA (PAC, classical variant) only rarely metastasizes, whereas CAMSG often shows metastases to the neck lymph nodes. Given the controversy, this review reappraises the definition, epidemiology, clinical presentation, diagnostic work-up, genetics, treatment modalities, and prognosis of PAC of the salivary glands with a particular focus on contrasting differences with CAMSG.
- Klíčová slova
- Cribriform adenocarcinoma of minor salivary glands, Pathology, Polymorphous adenocarcinoma, Polymorphous low-grade adenocarcinoma, Prognosis, Salivary glands, Therapy,
- MeSH
- adenokarcinom patologie chirurgie terapie MeSH
- lidé MeSH
- malé slinné žlázy * MeSH
- nádory slinných žláz patologie terapie MeSH
- prognóza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
PURPOSE: Thyroid nodules are of common occurrence in the general population. About a fourth of these nodules are indeterminate on aspiration cytology placing many a patient at risk of unwanted surgery. The purpose of this review is to discuss various molecular markers described to date and place their role in proper perspective. This review covers the fundamental role of the signaling pathways and genetic changes involved in thyroid carcinogenesis. The current literature on the prognostic significance of these markers is also described. METHODS: PubMed was used to search relevant articles. The key terms "thyroid nodules", "thyroid cancer papillary", "carcinoma papillary follicular", "carcinoma papillary", "adenocarcinoma follicular" were searched in MeSH, and "molecular markers", "molecular testing", mutation, BRAF, RAS, RET/PTC, PAX 8, miRNA, NIFTP in title and abstract fields. Multiple combinations were done and a group of experts in the subject from the International Head and Neck Scientific Group extracted the relevant articles and formulated the review. RESULTS: There has been considerable progress in the understanding of thyroid carcinogenesis and the emergence of numerous molecular markers in the recent years with potential to be used in the diagnostic algorithm of these nodules. However, their precise role in routine clinical practice continues to be a contentious issue. Majority of the studies in this context are retrospective and impact of these mutations is not independent of other prognostic factors making the interpretation difficult. CONCLUSION: The prevalence of these mutations in thyroid nodule is high and it is a continuously evolving field. Clinicians should stay informed as recommendation on the use of these markers is expected to evolve.
- Klíčová slova
- Adenocarcinoma, follicular, Carcinoma, papillary, NIFTP, Thyroid neoplasm/diagnosis, Thyroid neoplasm/genetics, miRNA,
- MeSH
- biologické markery metabolismus MeSH
- karcinom genetika metabolismus patologie MeSH
- lidé MeSH
- mutace genetika MeSH
- nádory štítné žlázy genetika metabolismus patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- biologické markery MeSH
