Expression of Periostin in Benign Salivary Gland Tumors.

Parotid tumors present a wide range of histological features, from benign to malignant. Periostin, an extracellular matrix protein specifically expressed in the periosteum and periodontal ligament, is isolated from osteoblast cell lines. It regulates fibrosis and collagen deposition and plays an important role in myocardial repair after myocardial infarction. It is also known to be involved in otorhinolaryngological-diseases. This study included 36 patients [38 specimens; 16 men and 20 women, mean age 59.2 (range 26-82) years] who underwent parotid tumor resection at the Division of Otorhinolaryngology, Tohoku Medical and Pharmaceutical University, between April 2017 and March 2022 and were clinically and pathologically diagnosed as having benign parotid tumors. Formalin-fixed, paraffin-embedded sections from the surgical specimens were autoclaved and immunostained with anti-periostin antibodies to evaluate the expression and distribution of periostin. Histologically, the tumors were diagnosed as pleomorphic adenomas in 15 cases (15 specimens), Warthin's tumors in 13 cases (15 specimens), basal cell adenomas in 2 cases (2 specimens), oncocytomas in 4 cases (4 specimens), and myoepitheliomas in 2 cases (2 specimens). An increased expression of periostin was found in 32 of 38 samples (84.2%) in the stroma of benign parotid tumors. Four distinct patterns of periostin expression were observed in benign parotid gland tumors: negative, superficial, infiltrative, and diffuse. Statistically significant differences were found between periostin expression patterns and histological classification of the tumors. Our results suggest that periostin may be involved in the pathogenesis of benign parotid tumors and could serve as a new biomarker for these tumors.

Increase in Chymase-Positive Mast Cells in Recurrent Pleomorphic Adenoma and Carcinoma Ex Pleomorphic Adenoma of the Parotid Gland.

Incomplete excision of pleomorphic adenoma (PA) may result in recurrent pleomorphic adenoma (RPA). Furthermore, long-term neglected PA may become carcinoma ex pleomorphic adenoma (CXPA). In the present study, the relationships between mast cell-derived chymase and these tumors were examined. The tumor tissues of PA consisted of either or both glandular and fibrotic structures. Histological features of RPA were almost similar to those of PA, except that they showed multinodular structures. CXPA is composed of a mixture of PA and carcinoma. The main stromal cells in PA were myofibroblasts, whereas fibroblasts constituted the main cellular portion in the stromal tissue of RPA. Cancer-associated fibroblasts (CAFs) were present abundantly in CXPA. With increased VEGF expression, neovascularization tended to increase in RPA or CXPA. Compared with PA, chymase-positive mast cells, as well as chymase gene expression, were increased in the tumor tissues from patients with RPA or CXPA. SCF, TGFß1, and PCNA-positive staining was widely observed in these tumor tissues. The above results suggest that mast cell-derived chymase through its direct or cooperative effects with other mediators may participate in the pathophysiology of RPA and CXPA.

A case of "ETV6-FISH-negative" secretory carcinoma of the parotid gland: immunohistochemical study.

Secretory carcinoma of the salivary glands is a relatively new disease concept, and is characterized by "morphological resemblance to mammary secretory carcinoma and ETV6-NTRK3 gene fusion." Herein we describe a confusing case and briefly discuss practical diagnostic problems. The patient was a 71-year-old Japanese man who had a tumor consistent with secretory carcinoma at the microscopic and immunohistochemical levels. Immunohistochemically, EMA and S100 protein were noted to be positive along with various cytokeratins as well as mammaglobin and pSTAT5. Moreover, vimentin was focally positive. Smooth muscle actin, p63, p40, and androgen receptor were negative. However, a search using fluorescence in situ hybridization did not reveal a definite split signal for the ETV6 gene. It is presumed that confirming the diagnosis of secretory carcinoma without genetic retrieval will be accepted as a diagnostic method, and we hope that worldwide general recognition may earlier reach "gradual acceptance."

Diagnostic Value of Superb Microvascular Imaging in Parotid Tumors.

BACKGROUND The aim of this study was to evaluate the clinical diagnostic value of superb microvascular imaging (SMI) in assessing vascular distribution, vascularity, and vessel morphology of parotid tumors (PTs). MATERIAL AND METHODS PT patients confirmed by postoperative histopathological detection and who underwent color Doppler flow imaging (CDFI), microvascular imaging (MVI), and SMI examination were recruited. PTs were classified into 3 groups: pleomorphic adenoma (PA), Warthin tumor (WT), and malignant PT (MT). The tumor vascular distribution, vascularity, and vessel morphology recorded by CDFI, MVI, and SMI were compared among PA, WT, and MT group. PT diagnosis was performed using histopathological detection. Fisher's exact test was used to compare the diagnostic sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy between SMI and MVI examination in PTs. RESULTS We enrolled 198 PTs consisting of 114 PAs, 56 WTs, and 28 MTs into our study. CDFI examination found no significant differences in vascular distribution and vascularity among the PA, WT, and WT groups. SMI examination found significant differences in vascular distribution and vascularity among the 3 groups. MVI found significant differences in vessel morphology, including uneven distribution of blood flow, arborization, and irregular blood flow among the PA, WT, and MT groups. SMI found significant differences in arborization and irregular blood flow, but none of the differences in uneven distribution of blood flow among the 3 groups were significant. The diagnostic sensitivity, specificity, and accuracy of SMI and MVI in PTs showed no significant differences. CONCLUSIONS SMI more accurately evaluated the vascular distribution and vascularity of PTs than CDFI. SMI might be a potential non-invasive diagnostic method for PTs in clinical practice.

Clinical characteristics of acinic cell carcinoma and secretory carcinoma of the parotid gland.

PURPOSE: Mammary analogue secretory carcinoma (SC) of the parotid gland is a relatively uncommon cancer associated with the ETV6-NTRK3 fusion product similar to breast cancer. The clinical characteristics and outcome of treatment were reviewed for patients with this tumor at our hospital. METHODS: In this retrospective case series, 24 patients with a diagnosis of acinic cell carcinoma (AcCC) of the parotid gland were classified as having either SC or AcCC based on analysis of the ETV6-NTRK3 fusion gene. These two groups were compared with respect to their clinical and imaging characteristics (MRI/US), cytologic findings, accuracy of fine-needle aspiration cytology and frozen section, treatment outcomes, and immunohistochemical findings. RESULTS: Based on re-classification by ETV6-NTRK3 fusion gene analysis, the diagnosis was SC in 14 patients and AcCC in 10 patients. The SC group had a significantly higher proportion of male patients and was also significantly younger than the AcCC group. Imaging studies revealed that SC was significantly more likely to show internal heterogeneity. Correct grading of both tumors was comparable by fine needle aspiration, with the rate being 60% for AcCC and 50% for SC. Diagnosis by frozen section biopsy diagnosis obtained the correct grade in 90% of the AcCC group and 93% of the SC group. CONCLUSIONS: In 24 patients previously diagnosed with AcCC, re-analysis of the ETV6-NTRK3 fusion product indicated that 14 patients actually had SC. Although AcCC and SC show similarities of their biological aggressiveness and prognosis, patients with SC were significantly more likely to be male and younger.

Recurrent Dermatofibrosarcoma Protuberans of the Parotid: A case report and review of literature.

In 1924, Darier and Ferrand described Dermatofibrosarcoma Protuberans as a progressive and recurring dermatofibroma. It is a locally aggressive sarcoma originating from dermal and subdermal tissue of the skin. It usually begins as a small plaque that grows over a period and later manifests as multiple small subcutaneous nodules. It is more commonly found in females as compared to males and typically occurs in between 2nd and 5th decades of life. Most frequently involved regions of the body are torso and proximal ends of extremities and very rarely head and neck region is the site of involvement. The mainstay of treatment of this entity is surgery. The rate of recurrence of this disease is very high in about 50% of the cases and it may also express rare distant metastasis. It is a radiosensitive tumour and radiation may play a role in reducing risk of recurrence. We present a case of a 35 years old male with recurrent Dermatofibrosarcoma Protuberans of right parotid gland.

Comparative Role of Matrixins in Diagnostics of Parotid Gland Tumors.

The benign and malignant neoplasms in parotid gland have similar clinical presentations despite different tumor growth rates. The study compared the clinical and morphological data as well as the results of ELISA for MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2 in salivary fluid yielded during primary examination of the patients with pleomorphic adenoma and adenocarcinoma of parotid gland. The examined biomarkers detected in salivary fluid in patients with various cancer types differed significantly (p≤0.05). The correlations between clinical identification of adenoma or adenocarcinoma, on the one hand, and the levels of MMP-8, TIMP-1, and TIMP-2, on the other hand, makes it possible to use the latter as biomarkers for early detection and comprehensive noninvasive differential diagnostics of these neoplasms.

Assessment of BRAF V600E (VE1) protein expression and BRAF gene mutation status in codon 600 in benign and malignant salivary gland neoplasms.

BACKGROUND: The role of BRAF mutations in cancerogenesis has been demonstrated in several solid tumor types. However, in salivary gland tumors, this genetic alteration is very uncommon, and its role still remains unclear. Thus, the aim of this study was to analyze BRAF V600E (VE1) protein expression with BRAF mutation status in codon 600, in malignant and benign salivary gland tumors. METHODS: Studies were performed on archived formalin-fixed paraffin-embedded tissue sections derived from 95 patients who underwent surgery for tumors of the salivary gland. Immunohistochemical staining (IHC) on tissue microarray slides was performed for evaluation of BRAF V600E (VE1) protein expression, and the automatic molecular diagnostics platform was used for the evaluation of mutations in codon 600 of BRAF gene. RESULTS: IHC cytoplasmic expression of BRAF V600E (VE1) protein was found in two of 95 cases: one case of adenocarcinoma NOS (one of three; 33%) and one case of carcinoma ex pleomorphic adenoma (one of five; 20%). Although, in IHC studies, nuclear BRAF V600E (VE1) protein expression was found in 14 (15%) of the analyzed cases: nine of 28 (32%) cases of pleomorphic adenoma, three of five (60%) cases of ductal carcinoma, one of nine (11%) case of mucoepidermoid carcinoma, and in one of five (20%) case of carcinoma ex pleomorphic adenoma. All cases were negative for polymerase chain reaction PCR-based analyses of BRAF mutations in codon 600. CONCLUSIONS: In studied salivary gland cancers, no PCR-based prove mutations of BRAF V600 were detected. Further molecular analyses are necessary to rapid molecular arrays for the identification of specific mutations, optimal for individualized targeted therapies.

Carcinoma ex basal cell adenoma of the parotid gland: A report of an extremely rare case.

Malignant non-basaloid tumors that arise from basal cell adenoma (BCA) are extremely rare. The patient was a 72-year-old Japanese male, who had noticed swelling of the left parotid region 21 years ago. A superficial lobectomy was performed. About 60% of the tumor was made up of cribriform and trabecular tissue composed of basaloid cells, which exhibited mild atypia and nuclear expression of ß-catenin. This portion of the tumor was considered to be a BCA. In the other part of the tumor, the proliferation of large eosinophilic atypical cells, most of which formed intraductal structures, was observed. These tumor cells displayed cellular atypia, and some of them formed Roman bridge structures or contributed to intracapsular invasion. Immunohistochemically, these cells were positive for cytokeratin 7, gross cystic disease fluid proten-15 (GCDFP-15), androgen receptor (AR), and mammaglobin (MMG) and exhibited a high Ki-67 labeling index. So, this portion of the tumor was considered to be a salivary duct carcinoma (SDC). The tumor's final diagnosis was SDC ex BCA (intracapsular type), which is extremely rare. GCDFP-15, AR, MMG, and Ki-67 are useful immunohistochemical markers for diagnosing SDC ex BCA.

Is There a Role for PET/CT Parameters to Characterize Benign, Malignant, and Metastatic Parotid Tumors?

OBJECTIVE: Assessment of benign and malignant lesions of the parotid gland, including metastatic lesions, is challenging with current imaging methods. Fluorine-18 FDG PET/CT is a noninvasive imaging modality that provides both anatomic and metabolic information. Semiquantitative data obtained from PET/CT, also known as PET/CT parameters, are maximum, mean, or peak standardized uptake values (SUVs); metabolic tumor volume; total lesion glycolysis; standardized added metabolic activity; and normalized standardized added metabolic activity. Our aim was to determine whether FDG PET/CT parameters can differentiate benign, malignant, and metastatic parotid tumors. MATERIALS AND METHODS: Thirty-four patients with parotid neoplasms underwent PET/CT before parotidectomy; maximum SUV, mean SUV, peak SUV, total lesion glycolysis, metabolic tumor volume, standardized added metabolic activity, and normalized standardized added metabolic activity were calculated on a dedicated workstation. Univariate analyses were performed. A ROC analysis was used to determine the ability of PET/CT parameters to predict pathologically proven benign, malignant, and metastatic parotid gland neoplasms. RESULTS: Fourteen patients had a benign or malignant primary parotid tumor. Twenty had metastases to the parotid gland. When the specificity was set to at least 85% for each parameter to identify cut points, the corresponding sensitivities ranged from 15% to 40%. Assessment of benign versus malignant lesions of parotid tumors, as well as metastasis from squamous cell carcinoma versus other metastatic causes, revealed that none of the PET/CT parameters has enough power to differentiate among these groups. CONCLUSION: PET/CT parameters, including total lesion glycolysis, metabolic tumor volume, standardized added metabolic activity, and normalized standardized added metabolic activity, are not able to differentiate benign from malignant parotid tumors, primary parotid tumors from metastasis, or metastasis from squamous cell carcinoma and nonsquamous cell carcinoma metastasis.

The role of Nrf2 in pathology of pleomorphic adenoma in parotid gland.

BACKGROUND: Pleomorphic adenoma (benign mixed tumor) is one of the most common salivary gland tumors. However, the processes involved in its carcinogenesis are not well defined. This study aimed to define the contribution of Nfr2 (nuclear factor (erythroid-derived 2)-like 2) to pleomorphic adenoma pathology. The Nrf2-controlled gene system is one of the most critical cytoprotective mechanisms, providing antioxidant responses. MATERIAL AND METHODS: The study was carried out in pleomorphic adenoma and control parotid gland tissues, investigating gene expression of NFE2L2, as well as KEAP1 (Kelch-like ECH-associated protein 1) and NQO1 (quinone oxidoreductase), at mRNA and protein (immunohistochemistry) levels. Functional evaluation of Nrf2 system in the parotid gland was evaluated in HSY cells (human parotid gland adenocarcinoma cells). RESULTS: Pleomorphic adenoma specimens showed cytoplasmic and nuclear Nfr2 expression in epithelial cells, as well as more variable lower Nrf2 level in mesenchymal cells. In the parotid gland, Nrf2 was expressed in cytoplasm of serous, mucous, and duct cells. Nuclear Nrf2 expression was predominantly seen in serous cells, whereas mucous and duct cells were mostly negative. Comparable mRNA levels of NFE2L2 and NQO1 genes and significantly higher expression of KEAP1 in pleomorphic adenoma were seen. HSY cell incubation with oltipraz demonstrated significant elevation of NFE2L2 after 24 and 48 hours of stimulation, whereas NQO1 was elevated, but significantly only after 24 hours, and KEAP1 expression remained unchanged. CONCLUSIONS: Summarizing both in vitro and in vivo observations, it can be stated that Nrf2 may play a role in the pathology of pleomorphic adenoma.

PRDM1 expression on the epithelial component but not on ectopic lymphoid tissues of Warthin tumour.

OBJECTIVE: To determine the role of PRDM1, a key molecule for modulating the immune cells, in Warthin tumour (WT) pathogenesis. SUBJECTS AND METHODS: Forty paraffin-embedded parotid tissues of patients (mean age: 62.08 ± 11.90) with WT were retrieved from the pathology archives of Qindu Hospital from January 2012 to December 2012. The PRDM1 expression was investigated in a cohort of WT by immunohistochemistry. RESULTS: PRDM1 was expressed only on the epithelial component but not on ectopic lymphoid tissue of the tumour. Statistically, PRDM1 expression rates between WT glandular epithelial cells (40/40 cases) and the tumour-adjacent tissues (0/9 cases), and WT germinal centres (0/34 cases) and tonsil tissues (10/10 cases) were significantly different (P < 0.001), respectively. CONCLUSIONS: The PRDM1 expression appeared to play an essential role in WT pathogenesis. A better understanding of it might give options for revealing possible novel management strategies.

A pediatric case of mammary analogue secretory carcinoma within the parotid.

Mammary analogue secretory carcinoma (MASC) is a recently described entity in the differential diagnosis of salivary gland tumors. It is notable for a characteristic t(12;15)(p13;q25) translocation that results in a unique fusion protein, ETV6-NTRK3. While several studies have retrospectively identified this translocation in cases previously diagnosed as a different salivary malignancy, there have been relatively few cases where this translocation was identified on initial pathology results, and fewer still in a pediatric population. We present a case of a 15 year old female with a slowly enlarging, painless, left facial mass. MRI demonstrated a cystic mass extending into the deep lobe of the parotid, and she underwent parotidectomy. The tumor cells stained positive for S100 and CK19. ETV6 translocation was present, confirming the diagnosis. Mammary analogue secretory carcinoma is a recently described tumor of the salivary glands, which often masquerades as more common primary salivary gland tumors and cysts. More research is needed to characterize the typical behavior of this neoplasm and the optimal treatment regimen. With identification of its characteristic translocation, mammary analogue secretory carcinoma can be easily differentiated from its more prevalent counterparts, and should therefore remain within the differential of the pathologist and head and neck surgeon.

Myoepithelial carcinoma of the parotid gland.

Myoepithelial carcinomas exhibit a wide spectrum of cytomorphologic features and diverse clinical outcomes. As a result of their morphologic heterogeneity, they can be confused easily with many tumours. Herein we report the morphological features of myoepithelial carcinoma in a 74-year-old female clinically presenting with a parotid mass. FNAB revealed hypercellular, three-dimensional clusters with considerable overlapping and crowding of pleomorphic neoplastic cells which consisted predominantly of spindle cells, with oval to elongated to spindle shaped nuclei showing considerable variation in size. The excised tumour was solid, with cells arranged in trabeculae, nests and cords. Tumour cells were mixed epithelioid and spindle with eosinophilic or clear cytoplasm, with eccentric nuclei and prominent nuclei. Neoplastic cells were found in blood vessels, in the skin and facial nerve. Tumour cells were immunopositive for PAS, PAS-D, S-100 protein, GFAP, P63, CK5/ CK6, CK7, and CK14. This case illustrates that cytological features in FNAB generally reflect the histology. FNAB was able to confirm the diagnosis and guide patient management.

[Patient-derived parotid gland pleomorphic adenoma organoid model and its preliminary histological and functional characterization].

Objective: To establish patient-derived organoid models of pleomorphic adenomas (PA) of the parotid gland and preliminarily characterize their histology, related biomarkers and functions. Methods: Fresh tumor tissue specimens were collected from surgical procedures of Oral and Maxillofacial Department. The harvested tissues were processed and cultured in a head and neck tumor organoid culture system to establish organoid models from parotid gland pleomorphic adenomas. The in vitro growth of PA organoids was recorded by light microscopy. The successfully established organoids were passaged and cryopreserved, and the cryopreserved PA organoids were revived and re-cultured to observe their viability and organoid regeneration ability. Histological characterization, as well as characterization and detection of related markers and functional proteins, were performed on the organoids, comparing them with the patient-derived tissues. Results: The constructed organoid model of pleomorphic adenoma exhibited a dense and compact three-dimensional spherical structure. Hematoxylin and eosin staining indicated morphological similarities between the organoid and its tissue of origin. Immunohistochemistry showed positive cytoplasmic staining for Calponin, cytokeratin 7, and epithelial membrane antigen in both the organoid and the source tumor tissue, suggesting consistent histopathological characteristics between the organoid and its tissue of origin. Periodic acid-Schiff staining of the organoid showed positive staining for glycogen, with positive staining located in the interior and periphery of the organoid, indicating that the organoid possessed secretory functions like the salivary gland. Conclusions: This study successfully constructed organoids of pleomorphic adenoma derived from patient samples. This model faithfully replicates the tissue morphology and biomarkers of the source tissue and exhibits biological functions associated with mucus secretion. It serves as a valuable in vitro model for studying the development and progression of salivary gland tumors.

[High-grade transformation in adenoid cystic carcinoma: a clinicopathologic study].

OBJECTIVE: To study the clinicopathologic features and possible molecular mechanisms of adenoid cystic carcinoma with high-grade transformation. METHODS: Four cases of adenoid cystic carcinoma with high-grade transformation were enrolled into the study. Immunohistochemical study for smooth muscle actin, p63, p53 and Ki-67 was carried out. C-myc gene status was analyzed by fluorescence in-situ hybridization. RESULTS: There were altogether 3 males and 1 female. The mean age of the patients was 55.5 years. Two patients died 17 months and 29 months after operation, respectively. One patient had distant metastasis 23 months after operation and was still alive at 26-month follow up. The remaining patient remained tumor free at 3-month follow up. High-grade transformation in adenoid cystic carcinoma presented either as poorly differentiated adenocarcinoma or undifferentiated carcinoma. Histologic examination showed sheets of pleomorphic tumor cells occupying more than one low-power field. The high-grade carcinoma cells showed increased nuclear-cytoplasmic ratio, prominent eosinophilic nucleoli and active mitosis (ranging from 8 to 25 per high-power field). Comedo necrosis was observed in 2 cases and multiple foci of calcifications in 3 cases. Immunohistochemical study demonstrated loss of myoepithelial differentiation, overexpression of p53 and high proliferative index by Ki-67. No c-myc translocation or copy-number changes were observed. CONCLUSIONS: High-grade transformation in adenoid cystic carcinoma is rare. The histopathologic features are rather distinctive and the biologic behavior is aggressive. C-myc gene mutation does not seem to play a key role in the pathogenesis.

Prognostic value of proliferating cell nuclear antigen in parotid gland cancer.

Although cell proliferation is related to tumour aggressiveness and prognosis, there are few studies describing the expression of proliferative markers in salivary gland cancer. Our aim was to assess the long-term prognostic value of the proliferating cell nuclear antigen (PCNA) in a large group of histologically different salivary gland cancers. We analysed the expression of PCNA in 159 patients with parotid gland cancer by means of immunohistochemistry. The mean follow-up time was 56.6 months. A high expression of PCNA showed a significant correlation to the patients' pathological lymph node stage (p = 0.004). A high PCNA expression significantly indicated a poor 5-year disease-free (p = 0.046) and overall survival rate (p = 0.018). The PCNA expression was the only prognostic factor for a worse 5-year disease-free and overall survival in acinic cell carcinomas (p = 0.004, p = 0.022). The correlation between PCNA expression and survival probabilities of salivary gland cancer might make proliferation markers helpful tools in patient follow-up, prognosis and targeted therapy in salivary gland cancer in future.

Aggressive meningiomas involving the parotid gland.

Parotid masses remain challenging secondary to the great diversity of primary tumors that may arise in the salivary glands and propensity for regional and even distant metastases to occur in this region. Meningioma must also be considered in the differential diagnosis of parotid masses, whether from direct extension, metastases, or as an extracranial primary. We herein report 4 cases of aggressive meningioma involving the parotid gland and the pathologic considerations in evaluating these tumors.