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Background: Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. This study was designed to identify valuable prognosticator in MEC., Methods: Histopathologic analysis, immunohistochemistry, and in situ hybridization were performed on 128 carcinomas diagnosed as MEC of the head and neck., Results: Expression of p16 was found in 96 cases (76%) of MEC. Lymphoid stroma was identified in 63 cases (49%). There was a significant correlation between loss of p16 expression and absence of lymphoid stroma. Expression of p16 was significantly associated with better clinicopathologic features. Lymphoid stroma was significantly associated with lower histologic grade. Overall survival (OS) was significantly longer in cases expressing p16 (P = 0.00096) and lymphoid stroma cases (P = 0.0023). Multivariate analysis revealed loss of p16 expression as negative prognosticators for OS., Conclusion: Our data showed p16 expression and the presence of lymphoid stroma were significantly associated with good clinical outcomes. Testing for these factors could lead to better prognostication and treatment of patients with MEC., Competing Interests: Declaration of Competing Interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Mucoepidermoid carcinomas (MECs) are the most common salivary gland malignancy and have a diverse histology. Many histologic variants of MEC have now been confirmed with characteristic molecular alterations involving CRTC1::MAML2 or CRTC1::MAML3 translocations. We here report a series of 7 trabecular variants of MEC which showed a predominant trabecular or nested pattern with either focal glandular differentiation or clear cell change and keloid-like fibrosis in the background. In addition, these tumors were either negative or showed only focal positivity for p63. Such features are not characteristic of known disease entities and resulted in an initial misdiagnosis of adenocarcinoma, not otherwise specified, or low-grade to intermediate-grade MEC with uncertainty. The patients' ages in our cohort ranged from 26 to 55 years with a female predominance (5/7). The tumors were located in the parotid gland (n=3), base of tongue (n=2), hard palate (n=1), and parapharyngeal space (n=1), with a median size of 1.5 cm. All 7 cases showed an MAML2 split pattern on fluorescence in situ hybridization analysis, and both RNA and whole-genome sequencing presented CRTC1::MAML2 translocation. All 7 cases showed a solid-predominant histology, and 3 cases displayed extracapsular extension. There were no other signs of high-grade histology and no recurrences or deaths occurred over a follow-up period of up to 79 months. We thus propose a unique trabecular variant of MEC that has atypical histologic and immunohistochemical features., Competing Interests: Conflicts of Interest and Source of Funding: Supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2020M3A9E4036528). The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Aims: Salivary duct carcinoma (SDC) is an aggressive salivary gland neoplasm with a poor prognosis. Morphologically, it has many variants including sarcomatoid SDC. We evaluated the morphological features, immunohistochemistry profile, and genomic alteration of the rare variant, sarcomatoid SDC., Methods and Results: We evaluated the clinicopathological and molecular pathology for rare variant of sarcomatoid SDC. Among 102 SDC patients, three had sarcomatoid SDC. Review of clinicopathological features and immunohistochemistry and targeted exome sequencing was performed according to carcinomatous and sarcomatoid areas, respectively. The tumors were present in two submandibular glands and one parotid gland. In one case, a SDC arose in carcinoma ex pleomorphic adenoma. All consisted of a conventional invasive ductal carcinoma area and sarcomatoid features including spindle cells and multinucleated giant cells. AR and epithelial membrane antigen (EMA) were positive in both carcinoma and sarcomatoid areas. Cytokeratin AE1/AE3 were negative in all sarcomatoid areas. Targeted exome sequencing revealed multiple heterogeneous alterations including PIK3CA and TP53. Genomic alterations were nearly identical between typical carcinoma and sarcomatoid areas., Conclusions: Clinicopathological features of sarcomatoid SDCs were not different from typical SDC, and genomic alteration according to subtypes was also similar to that of the conventional type. Androgen receptor (AR) expression is helpful in the diagnosis of SDC. The findings indicate that EMA and AR are useful in diagnosing sarcomatoid SDC when the tumor is composed of predominantly sarcomatoid components., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary gland. However, reports of high grade transformation in MEC are extremely rare, and only two cases have so far been described. Recent development of salivary gland pathology revealed recurrent gene rearrangements in many kinds of tumors, including MAML2 fusion of MEC. To date, the MAML2 status of high grade transformed MEC has not been studied. Here we report the first case of minor salivary gland origin high grade transformation in MEC with a MAML2 break apart FISH study. A 73-year-old woman presented with a 1-month history of left mandibular area swelling, and computed tomography and magnetic resonance imaging revealed a mass in the hard palate with various-sized lymphadenopathy of the neck. The resected tumor histologically consisted of two carcinomatous components. Approximately 30% of the tumor showed a conventional MEC feature, while 70% was comprised of a high grade transformed component. In the conventional MEC component, FISH revealed MAML2 rearrangement. High grade transformed cells showed multiple split signals, and the results were interpreted as rearrangement and polyploidy after comparison with 1p/19q FISH as validation. The patient received adjuvant radiation therapy after wide resection with neck dissection and retropharyngeal dissection. Nevertheless, as the remaining tumor grew up rapidly and metastatic lymph nodes were newly revealed, the patient expired 7 months after the diagnosis. We first report regarding a high grade transformation in MEC with polyploidy of the rearranged MAML2 gene and aggressive biological behavior.

Background: This study compared our proposed N classification including the addition of the number of positive lymph node (LN+) and extranodal extension (ENE) with the current and previous American Joint Committee on Cancer (AJCC) N classifications in salivary gland cancer (SGC)., Methods: This study involved 172 SGC patients who underwent surgery. Cox proportional hazard regression analyses were used to identify factors associated with overall survival (OS) and disease-free survival (DFS)., Results: In multivariate analyses, LN+ number, LN ratio, and ENE were associated with OS and DFS outcomes (all P < .05). Our new N classification proposed three categories: N0 (0 LN+), N1 (1 LN+), and N2 (≥2 LN+ or ENE). The C-index of our N classification showed improvement in OS prediction (0.768) compared with the AJCC seventh (0.743) and eighth (0.756) edition N classifications., Conclusions: Our proposed N classification incorporating LN+ number and ENE may improve prediction of post-treatment survival and recurrence in patients with SGC., (© 2020 Wiley Periodicals, Inc.)

Background: Lymphadenoma (LA) of the salivary gland, nonsebaceous type, is an uncommon benign lymphoepithelial neoplasm. The histogenesis of the lymphoid component of LA is under debate as in Warthin's tumor. A recent study has described immunoglobulin (Ig) class switching to IgG4 in a subset of Warthin's tumors. The aim of this study is to evaluate IgG4 status of LA and presume the role of IgG4 status in pathogenesis of LA., Materials and Methods: The distribution of IgG-positive and IgG4-positive cells was compared by immunohistochemistry among 15 lymphoepithelial lesions of the salivary gland (8 LAs, 3 lymphoepithelial carcinomas, and 4 lymphoepithelial cysts). Epstein-Barr virus in situ hybridization was also performed., Results: IgG-positive and IgG4-positive plasma cells were observed in all cases, but to a remarkable degree (IgG4>100/hpf) in 2 of 8 LAs. The IgG4 plasma cells in LA were distributed in interfollicular areas and in the vicinity of epithelial nests. Among all cases, the mean number of IgG4 plasma cells was not correlated with the presence of germinal centers (12/15) or Epstein-Barr virus positivity (2/15)., Conclusions: Increased IgG4 plasma cells in LA suggest involvement of an immune reaction in the pathogenesis of LA similar to Warthin's tumor.

Objective: Histological grade is the most important factor for defining treatment strategies and predicting prognosis for salivary gland carcinoma (SGC). We examined factors affecting long-term recurrence and survival among intermediate-grade SGC (IGSGC) patients to define optimal treatment modalities and outcomes., Methods: We reviewed the clinical and pathological data on 108 IGSGC patients who underwent definitive surgery with or without postoperative radiotherapy. We compared treatment outcomes by treatment strategies such as surgical extent for the primary tumor, neck dissection, or postoperative radiotherapy., Results: During a 103-month median follow-up, local, regional, and distant recurrences were detected in 14 (13.0%), 3 (2.8%), and 21 (19.4%) patients, respectively. The 10-year locoregional control (LRC), distant metastasis-free survival (DMFS), and overall survival (OS) rates were 83.1, 76.0, and 80.1%, respectively. Multivariate analyses identified a nonparotid primary site as an independent prognostic factor for LRC (p = 0.018). Adenoid cystic carcinoma and a positive pN classification were significantly unfavorable prognostic factors for DMFS (p = 0.025 and p = 0.030, respectively); overall advanced stage was an independent prognostic factor for OS (p = 0.020). Surgical extent, elective neck dissection, and postoperative adjuvant radiotherapy did not significantly affect treatment outcomes., Conclusion: Patients with early-stage IGSGC of parotid origin can achieve favorable treatment outcomes with conservative surgery alone., (© 2017 S. Karger AG, Basel.)

Background: Management of the neck in patients with salivary gland cancer is controversial. This study aimed to identify clinicopathologic characteristics associated with regional metastases and regional recurrence in patients with salivary gland carcinoma., Methods: Of 363 study patients, 51 underwent therapeutic neck dissection (TND) and 312 underwent either elective neck dissection (END, n = 110) or no neck dissection (NoND, n = 202). Univariate and multivariate analyses were performed to identify clinicopathologic characteristics associated with regional metastases and recurrence., Results: Pathologic neck metastases were identified in 17/110 (15.5%) END patients and neck recurrence was identified in 5/202 (2.5%) NoND patients. Histologic grade (P < 0.001), tumor site (P = 0.008), and lymphovascular invasion (P < 0.001) were independent risk factors for neck metastases. Nodal metastases were more common in high-grade tumors (P < 0.001), at levels I-III in END patients and levels I-V in TND patients. Multivariate analyses identified histologic grade (P = 0.020), clinical N2 classification (P = 0.007), and extranodal extension (P = 0.005) as independent factors for regional recurrence after treatment., Conclusions: Patients with high-grade cancers should receive END involving levels I-III, whereas patients with node-positive salivary cancers should receive comprehensive TND involving all levels (I-V)., (© 2015 Wiley Periodicals, Inc.)

Background: To investigate the role of lymph node density (LND) as an independent prognostic factor in high-grade salivary gland cancers., Methods: All 87 patients with high-grade salivary gland cancers underwent curative surgery combined with neck dissection and most of them received postoperative radiotherapy or chemoradiotherapy. LND was calculated as the ratio of positive lymph nodes to total lymph nodes harvested. Clinicopathologic variables associated with cancer-specific survival (CSS) and overall survival (OS) were identified by univariate and multivariate analyses using the Cox-proportional hazards model., Results: Salivary duct carcinoma was the most common tumor (54%), followed by carcinoma ex pleomorphic adenoma (22%), and others. The 5-year CSS and OS were 50.9% and 49.6%, respectively, during a median follow-up of 61 months. In univariate analysis, tumor site, pathologic nodal stage, overall tumor-node-metastasis (TNM) stage, primary tumor size > 3 cm, lymphovascular invasion, perineural invasion, extranodal extension, number of metastatic lymph nodes, and LND > 4.0 were significant prognostic factors for CSS and OS (P < 0.05 each). Tumor site, perineural invasion, and LND were independent prognostic factors for both CSS and OS in multivariate analysis (P < 0.01)., Conclusion: Our findings support the prognostic value of LND for high-grade salivary gland cancers., (© 2015 Wiley Periodicals, Inc.)

Background: Aspiration cytologic findings of mammary analogue secretory carcinoma (MASC), a newly established salivary gland neoplasm defined by a t(12;15)(p13;q25) ETV6-NTRK3 translocation, are not fully characterized to date. We report cytologic descriptions of nine cases of molecularly confirmed MASC, including two with unusual findings., Methods: Aspiration smears from nine MASCs of the salivary glands were retrospectively reviewed and analyzed according to the cellular and structural features of the corresponding surgical specimens., Results: Aspiration smears of MASC generally reflected the histologic diversity of the tumors. Among usual histologic findings, a micropapillary pattern was associated with a predominance of vacuolated individual cells on aspiration smears, a papillary-cystic pattern with a predominance of thin branching papillary structures, and a microcystic pattern with a predominance of irregular sheets of eosinophilic cells. There were two unusual cases, one with three-dimensional groups of high-grade atypical cells, and one with epithelial clusters floating in a notably mucinous background. These cases represented MASC with high-grade transformation and MASC with cystadenocarcinoma-like features, respectively. The secretory activity of MASC was not prominent in the aspiration specimens., Conclusions: Although unusual cases were present, most MASC cases showed characteristic cytologic findings, which could aid the cytologic diagnosis of MASC. And knowledge of the histologic spectrum of MASC, including high-grade transformation, could be valuable for cytological differential diagnoses of salivary gland tumors, and the management of patients with MASC., (© 2014 Wiley Periodicals, Inc.)

Importance: Second primary cancers (SPCs) are common in patients with head and neck squamous cell carcinoma, while the incidence and risk factors of SPC in patients with salivary gland cancers (SGCs) are largely unknown. This study aimed to examine the incidence of and risk factors for SPC in patients with SGC., Objective: To report the risk factors and incidence of SPC in patients with SGC and compare them with the values of newly developed cancers (NDCs) in a healthy population., Design, Setting, and Participants: A retrospective case-control study conducted at a university teaching hospital. The study population comprised 184 patients with SGC, without a history of cancer, who were treated between 2000 and 2010 and followed up for at least 2 years, and 200 healthy individuals (control group) who underwent medical examinations in health promotion programs during the same period., Interventions: All individuals received the diagnostic scrutiny including endoscopic and radiological examinations at initial staging and at follow-up. Individuals suspected of having SPC or NDC underwent histological confirmation., Main Outcomes and Measures: Risk factors of SPC development and cumulative incidence of SPC (or NDC) in each group., Results: The cumulative 2-, 5-, and 10-year rates of SPC were 4.4%, 8.3%, and 12.4%, respectively, and those of NDC were 1.1%, 3.4%, and 10.5%, respectively (P = .29). Except for the thyroid gland, SPC and NDC were located outside the head and neck region. Univariate analysis was unable to identify any variable significantly predictive of SPC or NDC., Conclusions and Relevance: In the present study, there was no statistical difference in the SPC cumulative incidence between the SGC and control groups, which might result from the possible limitation of a small sample size.

Background: We compared clinical outcomes between patients with salivary gland carcinomas preoperatively misdiagnosed as benign lesion and properly diagnosed as malignant lesion., Methods: The outcomes were compared between patients with benign lesion and malignant lesion (44 each) on preoperative fine-needle aspiration cytology diagnosis who underwent conservative or radical surgery., Results: Five-year lesion-free survival (DFS) rates were 86.8% for benign lesion and 76.3% for malignant lesion (p = .128). Surgical extent did not significantly affect locoregional recurrence and DFS (p = .360). Univariate analysis showed that sublingual gland tumor, positive resection margin, and extraparenchymal extension (EPE) were significantly associated with DFS (p < .05 each). On multivariate analysis, EPE remained an independent variable (p = .047, hazard ratio = 6.621, 95% confidence interval = 1.393-31.474)., Conclusions: The clinical outcomes of patients with salivary gland carcinomas misdiagnosed as benign are relatively favorable. Conservative surgery may be sufficient for patients with low-grade and T1-2 salivary gland carcinomas., (Copyright © 2013 Wiley Periodicals, Inc., A Wiley Company.)

Background: It is often difficult to diagnose salivary gland tumors that exhibit basaloid features differentially. The aim of this study was to identify additional morphological and immunohistochemical characteristics that can aid the diagnosis of basal cell adenocarcinoma (BCAC) of the salivary gland., Methods and Results: In total, 29 basal cell neoplasms [eight BCACs, 11 basal cell adenomas (BCAs) with capsular invasion, and 10 BCAs without capsular invasion] and 10 cases of adenoid cystic carcinomas (ACCs) were subjected to histopathology and immunohistochemical analyses for CK7, CK5/6, SMA, p63, calponin, p53, c-erbB2, CD117, β-catenin, EGFR, VEGF, Ki-67, and S100P protein expression. Compared to BCA without capsular invasion, the BCACs and BCAs with capsular invasion were more likely to be larger and have solid or cribriform patterns. Most BCACs and BCAs exhibited nuclear β-catenin expression. In all basal cell neoplasm cases, the clinical course after surgery with or without radiotherapy was indolent. β-catenin, CK5/6, CD117, and S100P protein were helpful for differentiating basal cell neoplasms from ACC., Conclusions: BCAs with capsular invasion shared several pathological features with BCACs, including a large size and frequent cribriform patterns but the malignant potential of these tumors seems highly limited and should be reexamined. β-catenin immunostaining may aid the differential diagnosis between basal cell neoplasms and ACCs., Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9637819101988153.

Unlabelled: Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various human cancers. This study examined the prognostic value of these metabolic tumor parameters measured by pretreatment (18)F-FDG PET/CT in patients with salivary gland carcinomas., Methods: Forty-nine patients with intermediate- or high-grade salivary gland carcinomas who underwent definitive surgery with or without radiotherapy or chemoradiotherapy were evaluated preoperatively by (18)F-FDG PET/CT. Maximum standardized uptake values (SUV max), MTV, and TLG were measured for each patient. Univariate and multivariate analyses were used to identify clinicopathologic and imaging variables associated with progression-free survival (PFS) and overall survival (OS). Univariate analyses included the following variables: age, sex, pT and pN classifications, overall pTNM stage, histologic grade, resection margin, tumor lymphovascular invasion and perineural invasion, postoperative adjuvant therapy, gross total volume, SUV max, MTV, and TLG., Results: The 3-y PFS and OS rates for all study patients were 66.9% and 81.6%, respectively. The median SUV max, MTV, and TLG were 5.1 (range, 1.7-21.5), 16.2 mL (1.0-115.1 mL), and 24.4 g (2.1-224.4 g), respectively. Univariate analyses showed that there were significant correlations between pT classification, pN classification, MTV, and TLG and both PFS and OS (P < 0.05). However, SUV max was not associated with either PFS (P = 0.111) or OS (P = 0.316). Multivariate analyses revealed that MTV (P = 0.011; hazard ratio, 11.50; 95% confidence interval, 1.45-91.01) and TLG (P = 0.038; hazard ratio, 3.55; 95% confidence interval, 1.07-11.76) were independent variables for PFS., Conclusion: Pretreatment values of MTV and TLG are independent prognostic factors in patients with intermediate or high-grade salivary gland carcinomas.

Background: The precise diagnosis of cervical lymph node metastasis (CLNM) of salivary gland cancer is important to determine the surgical extent and adjuvant therapy. This study assessed the clinical utility of (18)F-FDG PET in identifying CLNM in such patients., Methods: Fifty-four patients with intermediate or high-grade salivary gland cancer were preoperatively evaluated with (18)F-FDG PET/CT and CT/MRI. Histopathologic analysis of neck dissection tissues was used as the gold standard for assessing imaging techniques. Tumor and nodal maximum standardized uptake values (SUVmax) were measured for each patient. Univariate and multivariate analyses were used to identify CLNM predictive factors., Results: Of the 54 patients, 24 patients (44%) had CLNM. On a per-patient basis, the sensitivity and specificity of (18)F-FDG PET/CT and CT/MRI were not significantly different (92 vs. 83%, P = 0.625 and 93 vs. 97%, P = 1.000, respectively). On a per-level basis, (18)F-FDG PET/CT was significantly more sensitive and accurate than CT/MRI in the ipsilateral neck (96 vs. 54%, P < 0.001 and 92 vs. 83%, P < 0.001, respectively). The mean nodal SUVmax values of patients with and without nodal metastasis were 4.9 and 2.1, respectively (P = 0.008). Histologic grade was a significant predictor of CLNM (P = 0.014, odds ratio 14.46, 95% confidence interval 1.73-120.79)., Conclusions: (18)F-FDG PET/CT imaging and histologic grade are useful for detecting CLNM in patients with salivary gland carcinoma. This finding may guide preoperative planning for the necessity and extent of neck dissection in these patients.

In carcinoma ex pleomorphic adenoma (CXPA), pleomorphic adenoma (PA) and diverse carcinoma components showing luminal (ductal) or non-luminal (myoepithelial) differentiation coexist. To elucidate the clinicopathological implications of cellular differentiation in CXPA and the potential role of p53, vascular endothelial growth factor (VEGF), c-erbB-2, c-kit, and glucose transporter 1 (Glut-1) in carcinogenesis, we analyzed 11 CXPAs with luminal differentiation (CXPAs-LD) and 6 CXPAs with non-luminal differentiation (CXPAs-NLD) and compared protein expressions in residual PAs and carcinomas by immunohistochemistry. Among the CXPAs-LD, 5 were invasive and 8 were histologically high-grade tumors. The 5-year survival rate was 72.7%. P53, c-erbB-2, VEGF, and Glut-1 were more immunoreactive in carcinoma components than in PAs (P = 0.008, 0.004, 0.002, and 0.024, respectively); c-erbB-2 overexpression was associated with high histological grade (P = 0.024). Carcinoma components frequently lacked c-kit expression (P = 0.009). CXPAs-NLD were all low-grade and invasive with a larger mean tumor size (5.2 cm) than CXPAs-LD (3.3 cm) (P = 0.040). The patients remained disease-free without significant immunohistochemical expression. The immunoprofiles and clinical course of CXPA differed according to cellular differentiation. Therefore, it is important to report the histological subtype and to assess potential biomarkers in diagnostic and therapeutic trials.

Non-lymphoid mesenchymal neoplasms of salivary gland origin are rare, accounting for 1.9-5% of major salivary gland tumors. We describe the clinico-pathologic features of 18 cases of mesenchymal neoplasms of the major salivary glands experienced at Asan Medical Center, Seoul, Korea, from 1998 to 2004. Mesenchymal neoplasms accounted for 3.4% of the total of 524 major salivary gland tumors. The parotid gland was the preponderant site (15 cases). Thirteen tumors were benign, constituting 3.5% of the total of 371 benign neoplasms. Schwannomas were the most common benign tumors (six cases), followed by lipomas (three cases), plexiform neurofibroma, hemangioma, desmoid tumor, and solitary fibrous tumor (one each). The malignant tumors consisted of one dermatofibrosarcoma protuberans, synovial sarcoma, leiomyosarcoma, pleomorphic liposarcoma and desmoplastic small round cell tumor each. Immunohistochemical analysis for the expression of vimentin, actin, desmin, neuron-specific enolase, keratin, CD34, CD99 and bcl-2 contributed to the differential diagnoses. Genetic analysis for fusion transcripts was conclusive in the diagnosis of desmoplastic small round cell tumor, which is extremely rare at this location. Pre-operative imaging study and fine needle aspiration cytology had limitations in prediction of the mesenchymal nature of the tumors, due to either low index of suspicion, similarities to mixed tumors, or specimen inadequacy. Awareness of the development of various mesenchymal tumors in the major salivary glands could increase the accuracy of preoperative and postoperative diagnosis, and therapeutic efficacy.

Background: Salivary duct carcinoma (SDC) is associated with aggressive clinical behavior., Methods: We examined the prognostic values of clinicopathologic variables and hypoxia biomarker expression in 21 patients with SDC treated by resection with/without neck dissection and radiotherapy. Tissue microarrays constructed from tumor blocks were stained with monoclonal antibodies to hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase-9, glucose transporter-1, and erythropoietin receptor. Locoregional control and survival rates were calculated by the Kaplan-Meier method and prognostic factors were calculated from uni- and multivariate analyses., Results: The cervical nodal metastasis rate was 67% at initial diagnosis and the distant metastasis rate was 71% during follow-up. The only significant predictor of distant metastasis was nodal metastasis (P = 0.006). Actuarial 5-year locoregional control, distant metastasis-free survival, and overall survival rates were 57%, 40%, and 44%. Multivariate analysis showed that lymphovascular and perineural invasion and radiotherapy were independent predictors of overall survival (P < 0.025). None of the hypoxia biomarkers, however, was a significant predictor of locoregional control, distant metastasis, or survival., Conclusions: Lymphovascular and perineural invasion, but not hypoxia biomarkers, were significant prognostic factors for patients with SDC.

Unlabelled: The clinical utility of 18F-FDG PET in evaluating salivary gland malignancies has not been well defined. We therefore evaluated the utility of 18F-FDG PET in management for patients with salivary gland cancers., Methods: Thirty-four patients with newly diagnosed salivary gland cancers underwent CT and 18F-FDG PET before surgical resection with radiotherapy. The diagnostic accuracies of CT and 18F-FDG PET for detecting primary tumors and neck metastases were compared with a histopathologic reference. We determined the relationship between the maximum standardized uptake value (SUV) of the tumor and clinicopathologic parameters such as sex, age, local tumor invasion, T and N categories, TNM stage, and histologic grade, as well as their associations with disease-free survival (DFS)., Results: 18F-FDG PET was more sensitive than CT for the detection of primary tumors (91.2% vs. 79.4%; P < 0.05), cervical metastases (80.5% vs. 56.1%; P < 0.05), and distant metastases in 2 patients at initial staging. High-grade malignancies had higher mean maximum SUVs than did low- and intermediate-grade malignancies (4.6 vs. 2.8; P = 0.011). T and N categories were independent determinants of DFS (P < 0.05), but the maximum SUV (4.0) was not. During a mean follow-up of 25.1 mo, 18F-FDG PET correctly diagnosed local-regional recurrences in 6 patients and new distant metastases in 9 patients., Conclusion: Our findings indicate that, in patients with salivary gland malignancies, 18F-FDG PET is clinically useful in initial staging, histologic grading, and monitoring after treatment but not in predicting patient survival.