Acinic cell carcinoma (AciCC) is a common salivary gland malignancy, typically composed of neoplastic acinic cells with zymogen granules. The vast majority of cases are driven by a t(4;9)(q13;q31) leading to enhancer hijacking and upregulation of the NR4A3 gene. However, a minority of cases do not display NR4A3 overexpression on immunohistochemical examination and are negative for the rearrangement involving the NR4A3 gene when tested by FISH. Such cases overexpress NR4A2, and the protein product is detectable by immunohistochemistry. In this study, we aimed to assess the utility of NR4A2 and NR4A3 immunohistochemistry in the differential diagnosis of salivary gland tumors. Eighty-five cases of classic low-grade ACiCC, as well as 36 cases with high-grade transformation (HGT) and 7 high-grade AciCC cases were included in the analysis. NR4A3 was at least focally positive in 105/128 (82%) cases. Out of the 23 cases that were immunohistochemically negative for NR4A3, 6 displayed nuclear immunopositivity with the NR4A2 antibody. The NR4A3 rearrangement was confirmed by FISH in 38/52 (73%) cases. In addition, this is the first report of an NR4A2 rearrangement being detected by FISH in 2 AciCC cases that were negative for the NR4A3 rearrangement. Our analysis confirms that the majority of AciCC, including high-grade cases and cases with HGT, are immunopositive for NR4A3, and suggests that NR4A3 immunohistochemistry is a powerful tool in the differential diagnosis of salivary gland tumors. However, its utility is limited in sub-optimally fixed samples which often display weaker and focal positivity. Our study also indicates that in a minority of cases, AciCC might be negative for NR4A3 immunostaining, because the pathogenic genetic event in these cases is instead a rearrangement involving the NR4A2 gene.
- MeSH
- acinární karcinom * diagnóza genetika metabolismus MeSH
- buněčné jádro patologie MeSH
- DNA vazebné proteiny metabolismus MeSH
- imunohistochemie MeSH
- jaderné receptory - podrodina 4, skupina A, člen 2 metabolismus MeSH
- lidé MeSH
- nádorové biomarkery analýza MeSH
- nádory slinných žláz * diagnóza genetika patologie MeSH
- receptory thyreoidních hormonů metabolismus MeSH
- slinné žlázy patologie MeSH
- steroidní receptory * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Epidemiologic and clinicopathologic features, therapeutic strategies, and prognosis for acinic cell carcinoma of the major and minor salivary glands are critically reviewed. We explore histopathologic, histochemical, electron microscopic and immunohistochemical aspects and discuss histologic grading, histogenesis, animal models, and genetic events. In the context of possible diagnostic difficulties, the relationship to mammary analog secretory carcinoma is probed and a classification is suggested. Areas of controversy or uncertainty, which may benefit from further investigations, are also highlighted.
- MeSH
- acinární karcinom * epidemiologie metabolismus patologie terapie MeSH
- diferenciální diagnóza MeSH
- elektronová mikroskopie MeSH
- lidé MeSH
- malé slinné žlázy MeSH
- modely nemocí na zvířatech MeSH
- nádory slinných žláz epidemiologie metabolismus patologie terapie MeSH
- parotis MeSH
- předoperační péče MeSH
- prognóza MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
High-grade transformation of acinic cell carcinoma (AciCC) (previously referred to as dedifferentiation) is a rare phenomenon characterized by histologic progression of low-grade AciCC to high-grade adenocarcinoma or undifferentiated carcinoma. We report 9 new cases with immunohistochemical analysis and examination of HER-2/neu and p53 genes to further define the profile of this tumor. Histologically, the high-grade component was composed of polymorphic cells with a high mitotic rate arranged in glandular and solid growth patterns with comedonecrosis. The MIB-1 labeling indices were elevated in the high-grade component, as compared with the low grade conventional AciCC. The high-grade component of AciCC was characterized by strong membrane staining for CK18 and beta-catenin, and nuclear staining for cyclin-D1. HER-2/neu, androgen receptor, C-kit, and epidermal growth factor receptor were absent from both low-grade and high-grade components. In contrast, S-100 protein, alpha-1-antitrypsin, and lysozyme were lost only in high-grade foci of transformed AciCC. The median age was 61 years (with range from 43 to 76 y). Lymph node (LN) metastases were found in 5 of 9 cases (56%). Distant metastases to the lungs (n=4), pleura (n=2), brain (n=3), and peritoneum (n=1), and paraaortic, paratracheal, and mediastinal LNs (n=2) were observed. Six of 9 patients (66%) died from tumor dissemination, all with a median overall survival of 4.3 years (range: 1 to 9 y). The high propensity for LN metastases indicates the need for neck dissection at the time of diagnosis.
- MeSH
- acinární karcinom genetika metabolismus patologie MeSH
- dospělí MeSH
- geny erbB-2 MeSH
- geny p53 MeSH
- hybridizace in situ fluorescenční MeSH
- imunohistochemie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mutační analýza DNA MeSH
- nádorová transformace buněk genetika MeSH
- nádorové biomarkery analýza MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- nádory příušní žlázy genetika patologie MeSH
- receptor erbB-2 genetika MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
