Salivary Gland Tumor: A Review of 599 Cases in a Brazilian Population

Salivary gland tumors consist of a group of heterogeneous lesions with complex clinicopathological characteristics and distinct biological behaviors. Worldwide series show a contrast in the relative incidence of salivary gland tumors, with some discrepancies in clinicopathological data. The main aim of this study was to describe demographic characteristics of 599 cases in a population from Central Brazil over a 10-year period and compare these with other epidemiological studies. Benign tumors represented 78.3% of the cases. Women were the most affected (61%) and the male:female ratio was 1:1.6. Parotid gland tumors were the most frequent (68.5% of cases) and patient age ranged from 1 to 88 years-old (median of 45 years old). The most frequent tumors were pleomorphic adenomas (68.4%) and benign tumors were significantly more frequent in the parotid (75.9%), while malignant tumors were more frequent in the minor salivary glands (40%) (P < 0.05). In conclusion, women and the parotid gland were the most affected and pleomorphic adenoma was the most frequent lesion, followed by adenoid cystic carcinoma and Warthin’s tumor.     

Unique presentation of adenoid cystic carcinoma in postcricoid region: a case report and review of the literature

Malignant tumors of minor salivary glands are uncommon, representing only 2–4% of all head and neck malignancies. In the larynx, minor salivary gland tumors rarely occur and constitute less than 1% of laryngeal tumors. Most of the minor salivary gland tumors arise in the subglottis; however, they can also occur in the supraglottis in the false vocal cords, aryepiglottic folds, and caudal aspect of the epiglottis. The most common type of malignant minor salivary gland tumor is adenoid cystic carcinoma. In the last 20 years, only 40 cases of adenoid cystic carcinoma arising in variable locations of the larynx have been reported in the English language literature. We present a case of adenoid cystic carcinoma of the larynx arising in the inter-arytenoid and postcricoid region in a 54-year-old woman. To our knowledge, this is the first case of adenoid cystic carcinoma arising in this particular region of the larynx.     

Immunohistochemical Reactivity of Prostate-Specific Membrane Antigen in Salivary Gland Tumors

Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein that is overexpressed in the prostate gland and prostate cancer. PSMA has been recently used in positron emission tomography/computed tomography (PET/CT) imaging and targeted alpha-radiation therapy (TAT) for prostate cancer. Recently, the tubarial gland, a type of minor salivary gland that is described as a new organ situated in the pharynx, is reported to express PMSA. Here, we studied the expression of PSMA in common benign and malignant salivary gland tumors. We performed immunohistochemistry for PSMA in 55 salivary gland tumors comprising 10 pleomorphic adenomas, 10 Warthin tumors, 9 basal cell adenomas, 9 adenoid cystic carcinomas, 9 mucoepidermoid carcinomas, and 8 salivary duct carcinomas. PSMA was expressed in 97% of benign tumors and 77% of malignant tumors. Moreover, PSMA was expressed in 59% of normal salivary glands adjacent to the tumor. PSMA is relatively expressed in salivary gland tumors and salivary glands. Therefore, salivary gland neoplasm, and normal salivary gland, possibly demonstrate the accumulation of PSMA in PET/CT. Thus, we need to monitor the side effects in the salivary glands during TAT for prostate cancer.     

S-100 protein in salivary gland tumors: an immunohistochemical study of 129 cases

Immunohistochemical distribution of S-100 protein was evaluated in 129 tumors from major and minor salivary glands. Also, two sensitive immunoperoxidase avidin-biotin methods using either overnight incubation with primary antibody or pretreatment trypsin digestion and half-hour incubation were compared. Tumors with S-100 protein immunoreactivity were demonstrated in numerous benign and malignant histologic categories. Adenoid cystic carcinomas, carcinomas ex pleomorphic adenoma, clear cell carcinomas, and adenocarcinomas NOS showed inconsistent positive staining, whereas all monomorphic and pleomorphic adenomas and polymorphous low grade adenocarcinomas examined stained positively. No staining was observed in mucoepidermoid carcinomas or acinic cell carcinomas. Mesenchymal-like tumor cells with positive immunostaining were seen only in pleomorphic adenomas and trabecular-tubular adenomas. Equivalent results were found with both overnight and same-day digestion techniques. The consistent S-100 protein staining in some histologic tumor categories (pleomorphic and monomorphic adenoma and polymorphous low grade adenocarcinoma) compared to mucoepidermoid carcinoma that is devoid of S-100 protein immunoreactivity has application to some microscopic differential diagnostic situations. Inconsistent staining of adenoid cystic carcinomas and adenocarcinomas did not allow discrimination from other benign and malignant salivary gland tumors with similar histomorphology.     

Multiple Malignant Salivary Gland Neoplasms: Mucoepidermoid Carcinoma of Palate and Adenoid Cystic Carcinoma of Floor of Mouth

Salivary gland tumors usually occur as single lesions. To have more than one tumor is unusual. We report a case of an adult male who presented with a mucoepidermoid carcinoma involving the minor salivary glands of the palate at age 57 years, followed by an adenoid cystic carcinoma of the floor of mouth at age 63 years. The patient later succumbed to non-Hodgkin lymphoma at age 72 years. There are 31 acceptable cases of multiple malignant salivary gland neoplasms reported in the world literature. Multiple malignant tumors of the same histologic type are more common than those of different histologic type. Bilateral acinic cell adenocarcinoma was the most frequent combination of multiple salivary gland malignancy, accounting for 14 cases (10 synchronous and four metachronous). All involved the parotid glands bilaterally with the exception of one case that involved parotid and submandibular gland. Polymorphous low-grade adenocarcinoma accounted for three of the four cases of multiple malignant tumors involving minor salivary glands. Individuals with a history of malignancy are at risk for the development of additional malignant tumors and should receive appropriate clinical follow-up.

Human Kallikrein 8 Expression in Salivary Gland Tumors

The human kallikrein 8 protein (KLK8) is expressed in many normal tissues including esophagus, skin, testis, tonsil, kidney, breast, and salivary gland, and is found in biological fluids including breast milk, amniotic fluid, seminal fluid and serum. It has also been shown to be a biomarker and prognostic factor for breast cancer. The aim of this study was to determine whether KLK8 is expressed in salivary gland tissues and salivary gland tumors (both benign and malignant), in order to compare normal with tumor tissues. Pleomorphic adenomas, adenoid cystic carcinomas, polymorphous low grade adenocarcinomas, acinic cell carcinomas, mucoepidermoid carcinomas, and adenocarcinomas NOS of both minor and major salivary glands were examined. The results of this study indicate that most salivary gland tumors show high levels of expression of KLK8.     

Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study

BackgroundSalivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only.MethodsThis study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019.ResultsA total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin’s tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours.ConclusionsThis multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.     

Synchronous benign and malignant salivary gland tumors in ipsilateral glands: a report of two cases and a review of literature

BACKGROUND: Ipsilateral salivary gland tumors of different histologic types are rare and make up less than 0.3% of all salivary gland neoplasms. Only nine cases of synchronous benign and malignant ipsilateral parotid gland tumors have been described in the literature. METHODS: Two additional cases of synchronous benign and malignant neoplasms in the parotid gland are reported and discussed with a review of literature. RESULTS: Our first case describes a pleomorphic adenoma and a salivary duct carcinoma, an entity not previously reported in the literature. The second case documents the most common benign and malignant ipsilateral parotid gland neoplasm reported in this case series, a Warthin's tumor and a mucoepidermoid carcinoma. CONCLUSIONS: Synchronous salivary gland tumors exhibiting both benign and malignant components are uncommonly observed, with only nine cases published to date. We describe two additional cases of a synchronous benign and malignant ipsilateral parotid gland tumor.     

Neoplasms of the major and minor salivary glands. The diagnostic and therapeutic approaches and case presentations]

Between January 1982 and December 1988, 37 patients with neoplasm of salivary glands have been treated in our Division of Surgical Oncology. The sites of tumors were: parotid 26, submandibular gland 4, minor salivary gland 7. The preoperative diagnostic procedures were: sialogram, ultrasonogram, fine needle aspiration. Malignant tumors were 16:5 adenoca., 4 metastases, 3 adenoid cystic, 2 mucoepidermoid, 1 acinic cells, 1 lymphoma. Twenty-one patients affected by neoplasms and 5 by malignant tumors were treated with surgery only. Nine patients affected by malignant tumors were treated with surgery and RT. Two patients were treated with RT only. The first therapeutic step is surgery; in order to control local evolution of tumor, postoperative irradiation is recommended. Possible indications of preoperative diagnostic procedures and the therapeutic choices are discussed.     

Spinal metastasis of submandibular gland adenoid cystic carcinoma: a case report

BACKGROUND: Adenoid cystic carcinoma is a rare malignant tumor of the salivary glands, with pulmonary metastasis being the most common site of distant metastasis. CASE DESCRIPTION: The author reports an unusual case of intradural adenoid cystic carcinoma metastasis of the lumbar spine in a patient with recent prostate carcinoma suffering from progressive back pain. The primary submandibular tumor was resected 7 years before the appearance of the spine metastasis, and a prostatic carcinoma had been detected 1 year before. The patient died of systemically advanced disease a few months after surgical decompression. CONCLUSION: Late submandibular gland adenoid cystic carcinoma recurrence may present as an intradural lumbar spine metastasis. The case further displays difficulty in diagnosis and differentiation of metastasis in case of metachronous tumors.     

Tumors of the submaxillary gland.

This study reviews a thirty year experience with 217 patients who had a tumor of the submaxillary gland, comprising about 9 per cent of all patients with salivary neoplasms seen during the same period. Most of the tumors were malignant (56 per cent), with adenoid cystic carcinoma predominating, but the histologic type most frequently encountered was benign mixed tumor (43 per cent). Median age was fifty-four years in patients with malignant tumors compared with forty-six years in those with benign tumors, and 58 per cent were women. Asymptomatic swelling was the usual presenting complaint, and the clinical findings are summarized using a staging system recently proposed for patients with parotid tumors. Cervical lymph node metastasis occurred in at least 50 per cent of patients who had an adenocarcinoma or epidermoid, mucoepidermoid, or anaplastic carcinoma. Treatment was surgical and complete gland excision proved adequate in those with benign tumors. Radical neck dissection was performed in conjunction with submaxillary resection in most patients with malignant lesions, but radical en bloc resection was reserved for those few who had extensive or fixed disease. Net determinate "cure" rates at five and ten years (30 and 20 per cent, respectively) are distressingly low and compare unfavorably with those previously reported in patients treated for carcinoma of the parotid. The high local recurrence rate and the greater incidence in the submaxillary gland of more aggressive tumor types which metastasize readily suggest that current treatment should be more radical. It seems reasonable to expect that results might be improved if en bloc resections were more often performed in patients with less advanced disease, possibly in conjuction with intensive postoperative irradiation in selected cases.     

Parotid tumors in children.

Most salivary gland tumors, both benign and malignant, develop within the parotid glands. Although an overwhelming majority of tumors are reported in the adult population, the parotid glands are also the most frequently involved salivary glands in the pediatric age group. This study represents a combination of case material from the Armed Forces Institute of Pathology and our personal experiences. Of approximately 10,000 salivary gland lesions accessioned in all ages, only 124 tumors occurred in the parotid gland in children less than fifteen years old. There were ninety benign and thirty-four malignant lesions. The two most common benign masses were mixed tumors and vascular lesions. The most common malignancies were the mucoepidermoid and acinic cell carcinomas. We recommended that all solid tumors be removed by parotidectomy.     

Malignant salivary tumors—analysis of prognostic factors and survival

A group of 113 patients with malignant salivary gland tumors was retrospectively reviewed to analyze the association of clinical and histologic factors with survival. These factors were patient sex and age, tumor site, clinical stage, histologic diagnosis, tumor grade, and whether or not final surgical margins were clear. There were 57 parotid, 40 minor salivary, and 16 submandibular gland cancers. The histologic groups were mucoepidermoid carcinoma (49 patients), adenoid cystic carcinoma (31), adenocarcinoma not otherwise specified (18), acinic cell carcinoma (7), malignant mixed tumor (5), squamous cell carcinoma (2), and undifferentiated carcinoma (1). Univariate analysis of clinical factors showed that age and clinical stage significantly influenced survival. At 10 yr the predicted cumulative survival rates for Stage I, II, III, and IV tumors were 74%, 56%, 32%, and 10%, respectively. Tumor grade was the only significant histologic factor. This was most obviously reflected among patients with mucoepidermoid carcinomas. Cumulative survival at 5 yr was 94% for those with low-grade tumors and 26% for high-grade tumors. By multivariate analysis, clinical stage, age, and tumor grade remained highly significant. Analysis of patients with only Stage I and II disease demonstrated that the significant factors were patient age, tumor site, tumor grade, and whether or not surgical clearance was achieved. These results suggest that clinical stage should not be the exclusive determinant of the extent of surgery and that the selection of patients, for adjuvant therpay may be improved by an awareness of these prognostic factors.     

Malignant salivary tumors--analysis of prognostic factors and survival

A group of 113 patients with malignant salivary gland tumors was retrospectively reviewed to analyze the association of clinical and histologic factors with survival. These factors were patient sex and age, tumor site, clinical stage, histologic diagnosis, tumor grade, and whether or not final surgical margins were clear. There were 57 parotid, 40 minor salivary, and 16 submandibular gland cancers. The histologic groups were mucoepidermoid carcinoma (49 patients), adenoid cystic carcinoma (31), adenocarcinoma not otherwise specified (18), acinic cell carcinoma (7), malignant mixed tumor (5), squamous cell carcinoma (2), and undifferentiated carcinoma (1). Univariate analysis of clinical factors showed that age and clinical stage significantly influenced survival. At 10 yr the predicted cumulative survival rates for Stage I, II, III, and IV tumors were 74%, 56%, 32%, and 10%, respectively. Tumor grade was the only significant histologic factor. This was most obviously reflected among patients with mucoepidermoid carcinomas. Cumulative survival at 5 yr was 94% for those with low-grade tumors and 26% for high-grade tumors. By multivariate analysis, clinical stage, age, and tumor grade remained highly significant. Analysis of patients with only Stage I and II disease demonstrated that the significant factors were patient age, tumor site, tumor grade, and whether or not surgical clearance was achieved. These results suggest that clinical stage should not be the exclusive determinant of the extent of surgery and that the selection of patients, for adjuvant therapy may be improved by an awareness of these prognostic factors.     

Primary intraosseous ACC of mandible of possible salivary origin: A rare clinical entity

INTRODUCTION

Adenoid cystic carcinoma (ACC) is a malignant tumor mainly of salivary origin which is well known for its deceptively benign histologic appearance characterized by indolent, locally invasive growth with high propensity for local recurrence and distant metastasis.

PRESENTATION OF CASE

An unusual case of a 23-year-old woman was reported in our hospital. After investigations, it showed that it is a second primary intraosseous lesion of mandible that occurred subsequently after ACC of parotid gland. After diagnosis was established, resection of tumor and reconstruction with a free fibula flap was performed. Ten months follow-up showed no signs of recurrence or metastasis.

DISCUSSION

Among the salivary neoplasms, adenoid cystic carcinoma is very rare and intraosseous lesions are even rarer. We found a total of 26 cases of primary ACC of the mandible reported in the literature. Pain and swelling were the most frequent symptoms.

CONCLUSION

This case illustrates two key facts. First, not all cystic lesions are necessarily metastatic or recurrence. Second is, even though the exact origin of this tumor is unknown, central salivary gland tumors should be considered in the differential diagnosis of cystic lytic lesions in the mandible.     

Benign metastasizing pleomorphic adenoma of the parotid gland: a clinicopathologic puzzle

BACKGROUND: Pleomorphic adenoma constitutes the most common benign parotid gland tumor. Local recurrence after surgical treatment (lateral or total parotidectomy) has been described in 1% to 5% of cases. Malignant degeneration has been reported in 2% to 9% of cases of pleomorphic adenoma of salivary gland origin. Metastasizing pleomorphic adenomas without histologic evidence of malignancy have rarely been reported. Metastatic lesions have been discovered in bone, lymph nodes, the lung, oral cavity, pharynx, skin, liver, retroperitoneum, kidney, calvarium, and central nervous system. To the best of our knowledge, we hereby report the first case of pleomorphic adenoma of the parotid gland metastasizing to the ipsilateral maxilla. METHODS: We simultaneously examined apoptosis-related protein expression and markers of cell-proliferation activity in our case of benign pleomorphic adenoma metastasis and compared outcome with a control group of primary parotid pleomorphic adenomas. RESULTS: Analysis of p53, Bcl-2, MIB1, CD 105, p27, and p21 expression did not reveal significant differences between metastasizing pleomorphic adenoma of the salivary gland and the control group of primary parotid pleomorphic adenomas. CONCLUSIONS: Clinical rather than pathologic evidence seems to justify inclusion of metastasizing salivary pleomorphic adenoma in the group of low-grade malignant salivary tumors.     

Phase II trial of taxol in salivary gland malignancies (E1394): a trial of the Eastern Cooperative Oncology Group

BACKGROUND: Malignant tumors of the salivary glands make up approximately 5% of head and neck cancers. The Eastern Cooperative Oncology Group (ECOG) initiated a phase II evaluation of paclitaxel in patients with locally recurrent or metastatic salivary gland malignancies. METHODS: Chemo-naive patients with histologically confirmed recurrent or metastatic carcinoma of salivary gland origin (mucoepidermoid, adenocarcinoma, or adenoid cystic) were eligible. Patients were treated with paclitaxel, 200 mg/m(2) IV, every 21 days for a minimum of four cycles. RESULTS: Forty-five patients were treated. Eight partial responses were seen among the 31 patients with mucoepidermoid or adenocarcinoma histologic findings for a response rate of 26%. No responses were seen in the adenoid cystic carcinoma group. No significant difference in overall survival was found among these three histologic subgroups. CONCLUSION: Paclitaxel demonstrates moderate activity in salivary gland tumors of mucoepidermoid and adenocarcinoma histology. The poor response rate in adenoid cystic carcinoma is consistent with prior reports in this chemoresistant histologic subtype.