Salivary gland tumors among atomic bomb survivors, 1950-1987

Salivary gland tumors: an audit from a tertiary care centre in Northern India

Salivary gland tumors are relatively rare and can exhibit various clinical behaviors. The study aims to understand the natural history, pathology, diagnostic workup, and treatment strategies for these tumors to improve patient outcomes. The audit included patients with salivary gland tumors detected through radiology or cytology. Patients underwent surgery, with some receiving adjuvant treatment. Demographic information, treatment interventions, and survival outcomes were analyzed using SPSS software. A total 89 as malignant salivart gland tumours were audited Malignant tumors were predominantly found in the parotid gland, with fewer cases in the minor salivary gland and submandibular gland.The median age of presentation was 47 years, and the majority of patients were male. The study examined various pathological and clinical factors, including tumor stage, nodal status, and the presence of facial palsy. Surgical procedures and histological types of tumors were documented. Adverse histological features like positive margins, lymph node positivity, lympho-vascular invasion, extracapsular spread, and perineural invasion were noted. POSTOP RT was administered to high-risk patients. Most malignant salivary gland tumors were found in the parotid gland, while minor salivary gland tumors were underrepresented in the audit. Surgical practices were diverse. Radiotherapy protocols were relatively standardized. The study found that certain histological features, such as lymph node positivity, margin positivity, lympho-vascular invasion, perineural invasion, and extracapsular spread, were associated with adverse effects on DFS and OS. The findings suggest that specific histological features, including LVI and ECE have emerged as independent prognostic factors for DFS and OS.

Pathogenesis of Warthin's Tumor: Neoplastic or Non-Neoplastic?

Warthin's tumor is the second most frequent neoplasm next to pleomorphic adenoma in the salivary gland, mostly in the parotid gland. The epithelial cells constituting a tumor are characterized by the presence of mitochondria that undergo structural and functional changes, resulting in the development of oncocytes. In addition to containing epithelial cells, Warthin's tumors contain abundant lymphocytes with lymph follicles (germinal centers) that are surrounded by epithelial cells. The pathogenesis of Warthin's tumor is not fully understood, and several hypotheses have been proposed. The risk factors for the development of Warthin's tumor, which predominantly occurs in males, include aging, smoking, and radiation exposure. Recently, it has been reported that chronic inflammation and aging cells promote the growth of Warthin's tumor. Several reports regarding the origin of the tumor have suggested that (1) Warthin's tumor is an IgG4-related disease, (2) epithelial cells that compose Warthin's tumor accumulate mitochondria, and (3) Warthin's tumor is a metaplastic lesion in the lymph nodes. It is possible that the pathogenesis of Warthin's tumor includes mitochondrial metabolic abnormalities, accumulation of aged cells, chronic inflammation, and senescence-associated secretory phenotype (SASP). In this short review, we propose that DNA damage, metabolic dysfunction of mitochondria, senescent cells, SASP, human papillomavirus, and IgG4 may be involved in the development of Warthin's tumor.

Salivary Duct Carcinoma Arising in a Warthin Tumor of the Parotid Gland: A Rare Case Report with Review of Literature and PD-L1 Expression

Warthin's tumor is the second most common neoplasm of the parotid gland and consists of 2 components, including lymphoid stroma and glandular epithelium. Malignant transformation in this tumor is mostly seen in the lymphoid component; however, the carcinomatous transformation of the epithelial component is extremely rare. Cases of latter reported in the literature include squamous cell carcinoma, adenocarcinoma, mucoepidermoid carcinoma, oncocytic carcinoma, Merkel cell carcinoma, and undifferentiated carcinoma. We describe an extremely rare case of salivary duct carcinoma arising in a Warthin tumor in a 64-year-old male. Patient presented with an enlarging left parotid mass, biopsy of which showed salivary duct carcinoma. He subsequently underwent left parotidectomy along with left level II-IV lymph node dissection. Histology revealed both in situ as well as invasive salivary duct carcinoma arising from Warthin tumor. Immunohistochemistry showed tumor cells positive for CK7, AR, and GATA3, while p63 highlighted the myoepithelial cell layer in the in situ component. Her2 was 2+ by immunohistochemistry. In addition, PD-L1 IHC revealed positive expression with a combined positive score of 20%.

J, Rajagopal, Sarada. Huge Recurrent Mucoepidermoid Carcinoma of Parotid - a Rare Presentation

Mucoepidermoid carcinoma is the commonest primary malignant salivary gland tumor in both children and adults and constitutes around 2.8-16% of all salivary gland tumors. There is a wide age range of 3 to 95 years with a mean age of 47 years. We reported a case of 85 years old female patient, who presented to the department of Surgical Oncology, Srinivasan Medical College and Hospital, Trichy, with history of right parotid swelling for past 25 years, who had undergone Superficial parotidectomy 10 years back, followed by recurrence of tumor with huge increase in size, around 20 cm in greatest dimension. Right Completion Radical Parotidectomy with Modified Radical neck dissection type 1 with Cervical Rotation Flap cover was done and histopathological examination of the surgical specimen confirmed as high grade Mucoepidermoid carcinoma. Following surgery, the patient's outcome is better, uneventful with periodic regular follow-up.

Solitary Scalp Metastases of Parotid Pleomorphic Adenoma: A Case Report

Pleomorphic adenoma (PA) of the parotid gland is considered one of the commonest benign salivary gland neoplasms in both adults and pediatrics. However, metastatic pleomorphic adenoma (MPA) is extremely rare. In the past three decades, multiple cases were reported in the literature of MPA, where the metastatic phase has been preceded by a local recurrence for the majority of the cases. Metastases to the lungs, liver, bone, head and neck were reported. This paper will discuss a rare case presentation of MPA that metastasised solely to the face and scalp subcutaneous tissue with no other sites of metastases in a male adult.

Adamantinoma-like Ewing sarcoma of the salivary glands: a case report and systematic literature review

Adamantinoma-like Ewing sarcoma (ALES) of the salivary glands is an exceedingly rare malignancy defined by the t(11,22) EWSR1::FLI1 fusion, with complex epithelial differentiation. To identify features that can allow for better recognition of this disease entity, we reviewed all published reports of molecularly confirmed ALES of the salivary glands and explored epidemiological, clinical, radiological, pathological, and therapeutic characteristics of a population of 21 patients including a single newly reported patient from our group. We searched the English-language literature indexed in PubMed, Medline, Scopus, and Web of Science using the keyword 'Adamantinoma-like Ewing sarcoma' published up to June 2022. The median age at diagnosis was 46 years, and a slight female sex predilection was observed. Most tumors originated in the parotid gland (86%) and presented as a painless palpable mass with a median diameter of 3.6 cm. Metastatic dissemination was reported only in one patient (5%), and after a median follow-up of 13 months the 1-year overall survival rate was 92%. Salivary gland ALES were frequently misdiagnosed at presentation (62% of cases) and were pathologically characterized by the presence of highly monomorphic small round blue cells with infiltrative pattern and positive immunostaining for CD99 and high- and low-molecular weight cytokeratins. Epidemiological and clinical features of salivary gland ALES raise questions on the incorporation of this malignancy in the Ewing sarcoma family tumor group.

Risk of subsequent primary oral cancer in a cohort of 69,460 5-year survivors of childhood and adolescent cancer in Europe: the PanCareSurFup study

BACKGROUND

Survivors of childhood cancer are at risk of subsequent primary malignant neoplasms (SPNs), but the risk for rarer types of SPNs, such as oral cancer, is uncertain. Previous studies included few oral SPNs, hence large-scale cohorts are required to identify groups at risks.

METHODS

The PanCareSurFup cohort includes 69,460 5-year survivors of childhood cancer across Europe. Risks of oral SPNs were defined by standardised incidence ratios (SIRs), absolute excess risks and cumulative incidence.

RESULTS

One hundred and forty-five oral SPNs (64 salivary gland, 38 tongue, 20 pharynx, 2 lip, and 21 other) were ascertained among 143 survivors. Survivors were at 5-fold risk of an oral SPN (95% CI: 4.4-5.6). Survivors of leukaemia were at greatest risk (SIR = 19.2; 95% CI: 14.6-25.2) followed by bone sarcoma (SIR = 6.4, 95% CI: 3.7-11.0), Hodgkin lymphoma (SIR = 6.2, 95% CI: 3.9-9.9) and soft-tissue sarcoma (SIR = 5.0, 95% CI: 3.0-8.5). Survivors treated with radiotherapy were at 33-fold risk of salivary gland SPNs (95% CI: 25.3-44.5), particularly Hodgkin lymphoma (SIR = 66.2, 95% CI: 43.6-100.5) and leukaemia (SIR = 50.5, 95% CI: 36.1-70.7) survivors. Survivors treated with chemotherapy had a substantially increased risk of a tongue SPN (SIR = 15.9, 95% CI: 10.6-23.7).

CONCLUSIONS

Previous radiotherapy increases the risk of salivary gland SPNs considerably, while chemotherapy increases the risk of tongue SPNs substantially. Awareness of these risks among both health-care professionals and survivors could play a crucial role in detecting oral SPNs early.

Pathology Mimicking Orofacial Pain

A case of a 64-year-old woman is reported, who developed new-onset pain over a preexisting area of right mandibular fullness. Clinical examination, MRI, and fine-needle aspiration cytology confirmed the diagnosis of a benign parotid gland tumor-pleomorphic adenoma, which was treated by total parotidectomy with complete removal of the tumor. When evaluating a patient with orofacial pain, oral health care providers should be cognizant of all potential differential diagnoses, especially in the setting of red flags such as persistent or enlarging facial swelling/fullness.

Radiation induced mucoepidermoid carcinoma of the parotid gland following post-operative radiotherapy to the earlobe for keloid prophylaxis

Radiation-induced malignancies (RIMs) are rare but well-documented late toxicities associated with exposure to radiation or radiotherapy. A keloid scar is a common benign proliferation of scar tissue which commonly develops at the site of an injury, such as on the earlobe after ear-piercing. While typically reserved for management of malignancies, radiotherapy is often utilized in the management of some benign conditions, including keloids. Given the benign nature of keloids, any theoretical late toxicity from radiotherapy, particularly a life-threatening toxicity such as a RIM, is particularly concerning. Here, we report a case of a 34-year-old male who presented with a radiation induced mucoepidermoid carcinoma of the parotid gland which developed in a previously irradiated field ten years after the patient received electron radiotherapy for a keloid of the earlobe. Using available literature, we estimate the risk of a RIM of the parotid gland from a typical course of radiotherapy to the earlobe as 0.007% per year.

Head and neck cancer

Head and neck cancer is the seventh most common type of cancer worldwide and comprise of a diverse group of tumours affecting the upper aerodigestive tract. Although many different histologies exist, the most common is squamous cell carcinoma. Predominant risk factors include tobacco use, alcohol abuse, and oncogenic viruses, including human papillomavirus and Epstein-Barr virus. Head and neck malignancies remain challenging to treat, requiring a multidisciplinary approach, with surgery, radiotherapy, and systemic therapy serving as key components of the treatment of locally advanced disease. Although many treatment principles overlap, treatment is generally site-specific and histology-specific. This Seminar outlines the current understanding of head and neck cancer and focuses on treatment principles, while also discussing future directions to improve the outcomes of patients with these malignancies.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

Therapeutic challenges in radiation-induced salivary gland cancers

PURPOSE OF REVIEW

To give an overview of recent advances in therapeutic approaches of radiation-induced salivary gland cancers (ri-SGCs).

RECENT FINDINGS

Reirradiation with protons and carbon ions demonstrated to be feasible, safe and to offer good local control rates, with the possibility of overcoming radioresistance and dosimetric issues in previously irradiated cancer patients. Chromosomal rearrangements, gene fusions and expression profiles are important to identify specific cancer subtypes and can guide tailored systemic therapy.

SUMMARY

Ri-SGCs are rare and heterogeneous. Patients are often heavily pretreated and at risk of toxicities, and their management remain challenging. A multidisciplinary approach in referral centers is mandatory. Knowledge about SGCs cellular and molecular mechanisms is constantly evolving. In the last years, novel advances in therapeutic approaches, such as carbon ion radiotherapy, are emerging as safe and effective options in active treatment, but further efforts are needed to offer tailored personalized treatments and to improve survival.

Multidisciplinary Management of Radiation-Induced Salivary Gland Carcinomas in the Modern Radiotherapy Era

Simple Summary

Etiopathogenesis of salivary gland cancers [SGCs] is largely unknown, even if exposition to ionizing radiation is a recognized risk factor for SGCs development. To date, exhaustive data to guide clinicians in managing patients with radiation-induced [ri] SGCs are scarce and their treatment remains challenging. The purpose of this work is to describe and to analyze clinical and histopathological features, delivered treatments, and outcome of a series of patients with ri-SGCs treated at two Italian cancer referral sites. Given the rarity of ri-SGCs, this retrospective analysis conducted on a case series of 13 patients adds further knowledge to the paucity of literature. The management of these malignancies is extremely complex requiring a multidisciplinary treatment approach.

Abstract

Clinical data of ri-SGCs patients treated between 2015 and 2019 at a tertiary cancer center and a national hadron therapy facility were reviewed. Latent time (LT) from first RT to ri-SGCs diagnosis, overall (OS), and disease-free survival (DFS) were assessed. Thirteen patients developed 14 ri-SGCs (one patient had 2 synchronous ri-SCGs), after a median LT of 23 years (range 16–34). Parotid was the primary site in 8 cases (57%) and salivary duct carcinoma was the most frequent histotype (29%). Nine patients (69%) underwent surgery (Sx). Among them, 4 patients (31%) underwent Sx alone, 5 received post-operative treatments: 3 (23%) photon-based (X) reRT, one (8%) protons and carbon ions, one (8%) carbon ions only. One patient (8%) received definitive XRT. The remaining 3 patients (23%) received androgen deprivation therapy. With a median follow-up of 48 months (range 24–72), median OS and PFS were 74 and 24 months, respectively. In the subgroup of AR⁺ ri-SGCs, median PFS and OS were 12 and 74 months, respectively. Given the rarity of ri-SGCs, this work adds further knowledge to the paucity of literature. The management of these malignancies is extremely complex requiring a multidisciplinary treatment approach.

Acinic cell carcinoma of the parotid gland: from pathogenesis to management: a literature review

PURPOSE

Acinic cell carcinoma (ACCs) is uncommon malignant epithelial neoplasm of the salivary glands; the most common presentation is a well-defined painless solid mass. Diagnosis of ACCs is frequently complicated, due to its similarity with benign tumors.

METHODS

A review of the literature available on ACCs was carried out. Studies were sourced from PubMed with searching of relevant headings and sub-headings and cross-referencing.

RESULTS

There are no clear characteristics of ACCs found on CT, MRI and ultrasound imaging. The management of the ACC, a rare malignancy of the parotid gland, is often difficult and controversial. Radical surgery is the best treatment option. The role of radiotherapy remains controversial: the precise indications and oncologic effects of adjuvant radiotherapy in ACC of the parotid gland are not well known. There is insufficient literature regarding the chemotherapy for metastatic ACC.

CONCLUSION

Knowledge about ACC, a rare malignancy of parotid gland, has changed over the past few decades. More clinical randomized works would be needed, both to assess the real effectiveness of radio and chemotherapy and to have an unanimous consensus about their indications.

Molecular chaperones in tumors of salivary glands

The salivary glands are key components of the mouth and play a central role in its physiology. Their importance may be appreciated considering their number, occurrence in pairs, and distribution in the mouth: two parotids, two submandibular, two sublingual, and many other small ones scattered throughout the mouth. They produce saliva, without which ingestion of non-liquid nutrients and speech would be practically impossible. Nevertheless, the physiology and pathology of salivary glands are poorly understood. For instance, tumors of salivary glands occur, and their incidence is on the rise, but their etiology and pathogenesis are virtually unknown, although some risk factors have been identified. Likewise, the role of the chaperoning system in the development, normal functioning, and pathology, including carcinogenesis, remains to be determined. This scarcity of basic knowledge impedes progress in diagnosis, disease monitoring, and therapeutics of salivary gland tumors. We are currently involved in examining the chaperoning system of human salivary glands and we performed a search of the literature to determine what has been reported relating to oncology. We found data pertaining to six components of the chaperone system, namely HSP27, HSP60, HSP70, HSP84, HSP86, and GRP78, and to another HSP, the heme-oxygenase H-O1, also named HSP32, which does not belong in the chaperoning system but seemed to have potential as a biomarker for diagnostic purposes as much as the HSP/chaperones mentioned above. The reported quantitative variations of the six chaperones were distinctive enough to distinguish malignant from benign tumors, suggesting that these molecules hold potential as biomarkers useful in differential diagnosis. Also, the quantitative variations described accompanying tumor development, as observed in cancers of other organs, encourages research to elucidate whether chaperones play a role in the initiation and/or progression of salivary gland tumors.

Mucoepidermoid Carcinoma in Warthin Tumor of the Parotis in Childhood: A Case Report and Review of the Literature

Mucoepidermoid carcinoma arising in Warthin tumor of the parotid gland is an extremely rare entity. This is so far described only in the adult age group, and only one patient has been reported in the pediatric age group until today. Herein, we describe our patient and review the literature. This was a case of a 9-year-old girl admitted with a painless swelling in the left side of her face for at least 2 weeks. Histopathologic examination of total parotidectomy specimens revealed mucoepidermoid carcinoma arising in the Warthin tumor. This case is the youngest patient reported to date.

Characteristics of 5015 Salivary Gland Neoplasms Registered in the Hiroshima Tumor Tissue Registry over a Period of 39 Years

Salivary gland neoplasms are uncommon, and their epidemiology in Japan has not been well described. We conducted a retrospective review of salivary gland tumors registered in the Hiroshima Tumor Tissue Registry over a period of 39 years. The subjects were 5015 cases ranging in age from 6 to 97 (mean, 54.3) years old. The incidence of both benign tumors and malignant tumors increased with age until 60-69 years and then declined. Among the 5015 salivary gland neoplasms, 3998 (80%) were benign and 1017 (20%) were malignant. Pleomorphic adenoma (PA) was the most frequent benign tumor (68%), followed by Warthin tumor (26%). Adenoid cystic carcinoma (ACC) (27%) and mucoepidermoid carcinoma (MEC) (26%) were the two most frequent malignant tumors. Characteristically, there was a very low incidence of polymorphous adenocarcinoma in Japan. The average annual age-adjusted incidence rate per 100,000 population was 3.3 for benign tumors and 0.8 for malignant tumors. This is the large-scale multi-institutional analysis to describe the characteristics of salivary gland neoplasms, based on the pathological tissue registry data. We hope that the present data can contribute to early diagnosis and effective treatment of salivary gland tumors and to cancer prevention.

Salivary gland neoplasms in non-human primates: A case series and brief literature review

BACKGROUND

Salivary gland neoplasms are rare in non-human primates.

METHODS

Thirty-five years of pathology records were reviewed at the Southwest (SNPRC) and Yerkes (YNPRC) National Primate Research Centers. An in-depth literature search for salivary gland neoplasms in non-human primates was performed.

RESULTS

Seventeen salivary gland neoplasms (nine from SNPRC and YNPRC, eight from published literature) were identified. There were seven malignant, nine benign, and one of undetermined behavior identified in eight rhesus macaques, six baboons, a chimpanzee, a bonnet macaque, and a moustached tamarin. Parotid gland was the most frequent origin (n = 7), followed by mandibular (n = 4) or minor salivary glands (n = 2). Two animals with salivary gland adenoma had a history of prior radiation exposure.

CONCLUSIONS

Parotid glands are the most common origin for salivary gland neoplasms. Salivary gland neoplasms should be considered in the differential diagnoses of head and neck masses in non-human primates.

Infarcted Warthin tumor with mucoepidermoid carcinoma-like metaplasia: a case report and review of the literature

Background

Warthin tumor is a common, benign, painless salivary gland neoplasm. Rarely, Warthin tumors show large areas of squamous metaplasia; such Warthin tumors are called metaplastic or infarcted Warthin tumors because they are occasionally accompanied with tumor necrosis. The histological distinction between mucoepidermoid carcinomas and the metaplastic portions of Warthin tumors can be challenging; without a genetic study, mucoepidermoid carcinomas can be misdiagnosed as metaplastic Warthin tumors. We report a case of infarcted Warthin tumor partly showing mucoepidermoid carcinoma-like epithelial metaplasia. Only two cases of infarcted Warthin tumor similar to our case have been reported.

Case presentation

A 69-year-old Japanese man presented with a right parotid tumor. He had noticed the swelling on his right buccal region 1 year previously; the lesion had rapidly enlarged, with associated pain, 1 month previously. A radiological examination revealed a mass in the tail of the right parotid gland. Superficial parotidectomy was performed. On histological examination, the mass showed typical focal features of Warthin tumor; other areas showed coagulation necrosis of the tumor. These areas were surrounded by non-oncocytic epithelium comprising squamous and mucinous epithelial cells. Although cellular atypia of the non-oncocytic epithelium was not observed, a mixture of squamous and mucinous cells and lack of abundant lymphoid tissue mimicked low-grade mucoepidermoid carcinoma. Based on the results of fluorescence in situ hybridization, MAML2 gene rearrangement was not present in the typical portions of Warthin tumor and the mucoepidermoid carcinoma-like lesion. Therefore, a metaplastic or infarcted Warthin tumor was diagnosed. Our patient was disease-free 8 months after surgery.

Conclusions

Clinicians need to know that pain is a clinical symptom of infarcted/metaplastic Warthin tumor. Pathologists should be aware that a metaplastic Warthin tumor can mimic a low-grade mucoepidermoid carcinoma. Our case showed a mucoepidermoid carcinoma-like lesion that was confined near the area of tumor necrosis, and neither cytological atypia nor apparent invasive growth was present. These findings appeared to be histological clues of a metaplastic Warthin tumor rather than a mucoepidermoid carcinoma. Careful clinicopathological evaluation as well as genetic studies are needed to clarify the distinction between mucoepidermoid carcinoma and metaplastic portions of Warthin tumors.

AHNS series: Do you know your guidelines? Diagnosis and management of salivary gland tumors

This article is the next installment of the series "Do you know your guidelines" presented by the Education Committee of the American Head and Neck Society. Guidelines for the workup and management of tumors of the major and minor salivary glands are reviewed.

Mucoepidermoid carcinoma of the posterior-lateral border of tongue: a rare presentation

Mucoepidermoid carcinoma (MEC) is the most common malignant tumour of the major and minor salivary glands. Minor salivary glands are scattered in different areas of the oral cavity such as palate, retromolar area, floor of the mouth, buccal mucosa, lips and tongue, but so far, only a few lingual MEC cases have been documented in the literature and most of the studies have shown a predilection for base and dorsum of the tongue. We report a rare case of MEC involving the posterior-lateral border of the tongue.

Heterogeneous impact of smoking on major salivary gland cancer according to histopathological subtype: A case-control study

BACKGROUND

Major salivary gland cancers (M-SGCs) are rare, and have distinct heterogeneous histopathological subtypes. To the authors' knowledge, no consistent evidence of an association between cigarette smoking and the risk of M-SGCs has appeared to date. Furthermore, evidence of potential heterogeneity in the impact of smoking on histopathological subtypes is scarce, despite the fact that the histopathological subtypes of M-SGC exhibit different genetic features.

METHODS

The authors conducted a case-control study to investigate the association between smoking and M-SGC by histopathological subtype. Cases were 81 patients with M-SGCs and the controls were 810 age-matched and sex-matched first-visit outpatients without cancer treated at Aichi Cancer Center Hospital from 1988 to 2005. Odds ratios (OR) and 95% confidence intervals (95% CI) were assessed by conditional logistic regression analysis with adjustment for potential confounders.

RESULTS

Smoking was found to be associated with a significantly increased risk of M-SGC overall, with an OR of 3.45 (95% CI, 1.58-7.51; P =.001) for heavy smokers compared with never-smokers. A significant dose-response relationship was observed (P for trend, .001). When stratified by histological subtype, no obvious impact of smoking was observed among patients with mucoepidermoid carcinoma (MEC). In contrast, smoking demonstrated a significantly increased risk of M-SGCs other than MEC, with an OR of 5.15 (95% CI, 2.06-12.87; P<.001) for heavy smokers compared with never-smokers. The authors observed possible heterogeneity with regard to the impact of smoking on risk between MEC and M-SGCs other than MEC (P for heterogeneity, .052).

CONCLUSIONS

The results of the current study demonstrate a significant positive association between cigarette smoking and the risk of M-SGC overall. However, the impact of smoking appeared to be limited to M-SGCs other than MEC. Cancer 2018;124:118-24. © 2017 American Cancer Society.

Radiation-associated neoplasia: clinical, pathological and genomic correlates

Ionizing radiation is an established risk factor for the development of benign and malignant tumours. The epidemiology of radiation-associated neoplasia has been studied over the decades in diverse populations, including Japanese atomic bomb survivors, exposed communities following the Chernobyl nuclear power plant disaster, and paediatric and adult populations receiving therapeutic irradiation. Radiation has been associated with an increased risk of neoplasia throughout the human body, with some sites showing a markedly increased relative risk of developing tumours (thyroid; soft tissues), depending on patient age and the context of exposure. Although the mechanisms of cellular injury and repair resulting from ionizing radiation are well described, the genomics of radiation-induced tumours are still relatively poorly understood, with some exceptions, such as RET rearrangement in thyroid carcinomas following iodine-131 exposure and MYC amplification in cutaneous angiosarcoma following chest wall irradiation for breast cancer. This review will provide a general overview of the epidemiology, molecular mechanism, pathology and genomics of radiation-associated neoplasia in humans.

Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland

Malignant parotid tumors are heterogeneous and diverse. Accurate diagnosis requires a pathologist familiar with the various histologic subtypes, immunohistochemistry stains, and common translocations. Clinical course varies according to tumor subtype, ranging from indolent, slow-growing adenoid cystic carcinoma to rapidly progressive, possibly fatal, salivary ductal carcinoma. Histologic grade is important in prognosis and therapy. Surgery remains the mainstay of treatment when negative margins can be achieved. Radiation improves locoregional control of tumors with high-risk features. Chemotherapy for parotid tumors can be disappointing. Studies of new targeted therapies have not offered significant benefits.

Cross-sectional imaging in cancers of the head and neck: how we review and report

Cancer of the head and neck is the sixth most frequent cancer worldwide and associated with significant morbidity. The head and neck area is complex and divided into various anatomical and functional subunits. Imaging is performed by cross-sectional modalities like computed tomography, magnetic resonance imaging, ultrasound and positron emission tomography-computed tomography, usually with fluorine-18-deoxy-D-glucose. Therefore, knowledge of the cross-sectional anatomy is very important. This article seeks to give an overview of the various cross-sectional imaging modalities used in the evaluation of head and neck cancers. It briefly describes the anatomy of the extracranial head and neck and the role of imaging as well as the imaging appearance of tumours and their extension to lymph nodes, bone and surrounding tissue. The advantages and disadvantages as well as basic requirements of the various modalities are described along with ways of optimizing imaging quality. A general guideline for prescription of the various modalities is given. Pitfalls are many and varied and can be due to anatomical variation, due to pathology which can be misinterpreted and technical due to peculiarities of the various imaging modalities. Knowledge of these pitfalls can help to avoid misinterpretation. The important points to be mentioned while reporting are also enumerated.

Salivary acinic cell carcinoma: reappraisal and update

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.

Genetic variants in DNA double-strand break repair genes and risk of salivary gland carcinoma: a case-control study

DNA double strand break (DSB) repair is the primary defense mechanism against ionizing radiation-induced DNA damage. Ionizing radiation is the only established risk factor for salivary gland carcinoma (SGC). We hypothesized that genetic variants in DSB repair genes contribute to individual variation in susceptibility to SGC. To test this hypothesis, we conducted a case-control study in which we analyzed 415 single nucleotide polymorphisms (SNPs) in 45 DSB repair genes in 352 SGC cases and 598 controls. Multivariate logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Rs3748522 in RAD52 and rs13180356 in XRCC4 were significantly associated with SGC after Bonferroni adjustment; ORs (95% CIs) for the variant alleles of these SNPs were 1.71 (1.40-2.09, P=1.70 × 10^-7) and 0.58 (0.45-0.74, P=2.00 × 10^-5) respectively. The genetic effects were modulated by histological subtype. The association of RAD52-rs3748522 with SGC was strongest for mucoepidermoid carcinoma (OR=2.21, 95% CI: 1.55-3.15, P=1.25 × 10^-5, n=74), and the association of XRCC4-rs13180356 with SGC was strongest for adenoid cystic carcinoma (OR=0.60, 95% CI: 0.42-0.87, P=6.91 × 10^-3, n=123). Gene-level association analysis revealed one gene, PRKDC, with a marginally significant association with SGC risk in non-Hispanic whites. To our knowledge, this study is the first to comprehensively evaluate the genetic effect of DSB repair genes on SGC risk. Our results indicate that genetic variants in the DSB repair pathways contribute to inter-individual differences in susceptibility to SGC and show that the impact of genetic variants differs by histological subtype. Independent studies are warranted to confirm these findings.

Genome-wide association study identifies common genetic variants associated with salivary gland carcinoma and its subtypes

BACKGROUND

Salivary gland carcinomas (SGCs) are a rare malignancy with unknown etiology. The objective of the current study was to identify genetic variants modifying the risk of SGC and its major subtypes: adenoid cystic carcinoma and mucoepidermoid carcinoma.

METHODS

The authors conducted a genome-wide association study in 309 well-defined SGC cases and 535 cancer-free controls. A single-nucleotide polymorphism (SNP)-level discovery study was performed in non-Hispanic white individuals followed by a replication study in Hispanic individuals. A logistic regression analysis was applied to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). A meta-analysis of the results was conducted.

RESULTS

A genome-wide significant association with SGC in non-Hispanic white individuals was detected at coding SNPs in CHRNA2 (cholinergic receptor, nicotinic, alpha 2 [neuronal]) (OR, 8.55; 95% CI, 4.53-16.13 [P = 3.6 × 10(-11)]), OR4F15 (olfactory receptor, family 4, subfamily F, member 15) (OR, 5.26; 95% CI, 3.13-8.83 [P = 3.5 × 10(-10)]), ZNF343 (zinc finger protein 343) (OR, 3.28; 95% CI, 2.12-5.07 [P = 9.1 × 10(-8)]), and PARP4 (poly(ADP-ribose) polymerase family, member 4) (OR, 2.00; 95% CI, 1.54-2.59 [P = 1.7 × 10(-7)]). Meta-analysis of the non-Hispanic white and Hispanic cohorts identified another genome-wide significant SNP in ELL2 (meta-OR, 1.86; 95% CI, 1.48-2.34 [P = 1.3 × 10(-7)]). Risk alleles were largely enriched in mucoepidermoid carcinoma, in which the SNPs in CHRNA2, OR4F15, and ZNF343 had ORs of 15.71 (95% CI, 6.59-37.47 [P = 5.2 × 10(-10)]), 15.60 (95% CI, 6.50-37.41 [P = 7.5 × 10(-10)]), and 6.49 (95% CI, 3.36-12.52 [P = 2.5 × 10(-8)]), respectively. None of these SNPs retained a significant association with adenoid cystic carcinoma.

CONCLUSIONS

To the best of the authors' knowledge, the current study is the first to identify a panel of SNPs associated with the risk of SGC. Confirmation of these findings along with functional analysis of identified SNPs are needed.

An epidemiological evaluation of salivary gland cancer in the Netherlands (1989-2010)

BACKGROUND

The relative 5-year survival rate of salivary gland cancer is moderate at best. This study was set up to evaluate whether the improvements in diagnosis and treatment in the last decades impacted the incidence, mortality and survival of salivary gland cancer.

METHODS

Data on patients with salivary gland cancer from 1989 through 2010 were extracted from the Netherlands Cancer Registry (NCR); we examined incidence, mortality and relative survival. Furthermore, information on sex, age, tumor stage, histology, and treatment was taken into account.

RESULTS

A total of 2737 patients were included. Fifty-three percent (53%) were males and 47% were females with a significant higher proportion of early stages in women. In 2010, the incidence rate (European Standardized Rate (ESR)) of salivary gland cancer was 0.9 per 100,000 per year. The estimated annual percentage change in incidence rate since 1989 equaled 0.6% (95%CI: -0.2-1.4). Mortality rates (ESR) decreased in men until 1997 and increased thereafter. Mortality in women remained stable at 1.5 per 100,000. Over time more patients were treated by surgery and radiotherapy (p<0.001). The relative five-year survival rate equaled 69% and did not change in time.

CONCLUSION

We observed no relevant changes in incidence or mortality rates in the last two decades. Despite the increased combined treatment by surgery and radiotherapy, survival did not improve. This implies an urgent need for the development of new effective treatment modalities.

Invasive carcinoma arising from sclerosing polycystic adenosis of the salivary gland

Sclerosing polycystic adenosis is a rare salivary gland lesion. Recently, this entity has been regarded as a neoplastic lesion of low-grade malignant potential but, to date, no invasive carcinoma, metastases, or associated mortality have been reported. We report the first case of an invasive carcinoma component in a recurrent sclerosing polycystic adenosis lesion.

Salivary gland malignancies in children

With an annual incidence of less than 1 per million, salivary gland malignancies in children are rare, constituting less than 10% of pediatric head and neck cancer. Although over 20 histologic types of salivary gland cancer have been reported in adults, a smaller number have been observed in the pediatric population. Mucoepidermoid carcinoma is the most common histologic type, followed by acinic cell carcinoma. Since the majority of salivary gland carcinomas are diagnosed at an early stage, the overall prognosis is often favorable with complete surgical resection. To date, no prospective or retrospective data comparing outcomes of surgery alone versus multimodality therapy in the management of salivary gland malignancies in the pediatric population exists. Consequently, management decisions are made on a case-by-base basis, taking prognosis, treatment-related morbidity, and long-term sequelae into account.

Genetic variation in MDM2 and p14ARF and susceptibility to salivary gland carcinoma

Background

The p14^ARF/MDM2/p53 pathway plays an important role in modulation of DNA damage and oxidative stress responses. The aim of this study was to determine whether genetic variants in MDM2 and p14^ARF are associated with risk of salivary gland carcinoma (SGC).

Methods

Four single nucleotide polymorphisms (SNPs) in MDM2 and p14^ARF (MDM2-rs2279744, MDM2-rs937283, p14^ARF-rs3731217, and p14^ARF-rs3088440) were genotyped in 156 patients with SGC and 511 cancer-free controls. Multivariate logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

MDM2-rs2279744 was significantly associated with a moderately increased risk of SGC (OR, 1.5, 95% CI, 1.1–2.2). There was a trend toward significantly increased SGC risk with increasing number of risk genotypes of the four polymorphisms (P_trend = 0.004). Individuals carrying 3–4 risk genotypes in MDM2 and p14^ARF were at increased SGC risk (OR, 2.0, 95% CI, 1.1–2.7) compared with individuals carrying 0–2 risk genotypes. Moreover, the combined effect of risk genotypes of MDM2 and p14^ARF was more pronounced among young subjects (≤45 years), female subjects, subjects with race/ethnicity other than non-Hispanic white, ever-smokers, and ever-drinkers.

Conclusion

Our results support the involvement of SNPs of MDM2 and p14^ARF, either alone or more likely in combination, in susceptibility to SGC. Larger studies are needed to validate our findings.

An unusual localization of a pleomorphic adenoma in the rhinopharynx

Pleomorphic adenoma is the most common benign tumor of the parotid glands. Rarely it may arise from minor salivary glands of the upper aerodigestive tract. A 57-year-old woman was admitted at our institution presenting with nasal obstruction. Endoscopic evaluation revealed a pedicled mass in the rhinopharynx. After radiological examination, we opted for a transnasal endoscopic-assisted excision of the mass under general anaesthesia. Histological evaluation deponed for pleomorphic adenoma with clear surgical margins. No endoscopic evidence of local recurrence has been shown after 48 months of followup. In the literature, few cases of pleomorphic adenoma arising in the rhinopharynx have been reported. The introduction of endoscopy, as shown by our experience, leads to important benefits in the identification, treatment, and followup of such rhinopharyngeal benign tumors.

Functional single-nucleotide polymorphisms in the BRCA1 gene and risk of salivary gland carcinoma

OBJECTIVES

Polymorphic BRCA1 is a vital tumor suppressor gene within the DNA double-strand break repair pathways, but its association with salivary gland carcinoma (SGC) has yet to be investigated.

MATERIALS AND METHODS

In a case-control study of 156 SGC patients and 511 controls, we used unconditional logistical regression analyses to investigate the association between SGC risk and seven common functional single-nucleotide polymorphisms (A1988G, A31875G, C33420T, A33921G, A34356G, T43893C and A55298G) in BRCA1.

RESULTS

T43893C TC/CC genotype was associated with a reduction of SGC risk (adjusted odds ratio=0.55, 95% CI: 0.38-0.80, Bonferroni-adjusted p=0.011), which was more pronounced in women, non-Hispanic whites, and individuals with a family history of cancer in first-degree relatives. The interaction between T43893C and family history of cancer was significant (p=0.009). The GATGGCG and AACAACA haplotypes, both of which carry the T43893C minor allele, were also associated with reduced SGC risk.

CONCLUSION

Our results suggest that polymorphic BRCA1, particularly T43893C polymorphism, may protect against SGC.

An overview of the rare parotid gland cancer

Cancer of the parotid gland is relatively rare, but carries poor prognosis owing to its prevailing distant metastases. In addition to the disease's basic epidemiology and pathology, we review some current discoveries of its tumorigenesis molecular mechanism. Based on published salivary gland cancer clinical trial data, non-surgical antitumor efficacies amongst a range of chemotherapy, radiation, and concurrent therapy regimens are compared. We also present the current development status of novel radiation therapy and targeted therapeutics, focusing on intensity-modulated radiation therapy (IMRT), and epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) blockages, which are showing promise for improving parotid gland cancer management.

[SDHB expression in Warthin's tumour]

INTRODUCTION

Succinic dehydrogenase subunit B (SDHB) is an enzyme belonging to the mitochondrial complex II. The aim of this study is to analyse SDHB expression in a series of Warthin's tumours, studying its relationship with oncocytic changes, constantly present in this form of tumour.

MATERIAL AND METHODS

In resection tumour specimens from a series of ten Warthin's tumours (all from the parotid gland), immunohistochemical expression of SDHB was analysed using a commercially-available monoclonal antibody.

RESULTS

The Warthin's tumours studied affected 10 men (mean age: 64.2 yrs, range 40-80), all with smoking habits, and 2 with metachronous bilateral involvement. Two patients presented associated urothelial carcinoma. Our SDHB study showed marked reactivity (++/+++) in all cases in the oncocytic epithelial component and also in striated duct cytoplasm (+) from non-tumorous parotid tissue. Expression was not influenced by age, smoking intensity or bilateral character. One of the tumours showed squamous metaplasia foci with SDHB-negativity at this level.

DISCUSSION AND CONCLUSIONS

Due to the constant and intense SDHB reactivity in oncocytic cells in our observations, oncocytic changes are not considered to be associated with defective enzyme activity in the mitochondrial complex II. Strong SDHB reactivity is an additional marker of oncocytic changes in Warthin's tumour. Neither of these facts has been described previously.

Complication of adenoid cystic carcinoma and sialolithiasis in the submandibular gland: report of a case and its etiological background

The authors report a case of adenoid cystic carcinoma (ACC) complicated with sialolithiasis of the submandibular gland. The patient was a 43-year-old female with a history of papillotubular carcinoma of the breast almost at the same time. She had noticed a swelling in her sublingual area for 10 years, which was later diagnosed by her dentist to be due to a sialolith in the left submandibular gland. After several years of observation, the patient was referred to have her left submandibular gland, containing the stone, surgically removed with a diagnosis of atrophic sialadenitis. Histopathologically, the submandibular gland was extensively replaced with fibrous granulation tissue, in which there were small but invasive foci of ACC. The present case indicates that ACC could arise in the background of chronic sialadenitis. It is suggested that long-standing sialadenitis cases should be carefully examined to exclude suspicion of malignancy before surgery.

Cancer of the parotid gland; long-term follow-up. A single centre experience on recurrence and survival

BACKGROUND

The aim of the study was to investigate the results of treatment of malignant parotid gland tumours at a single centre during a 56 year period, focusing on tumour control and survival.

PATIENTS AND METHODS

At Uppsala University Hospital, Sweden, 144 patients (73 male and 71 female) with parotid cancer were treated between 1948 and 2004. The mean and median ages were 62 and 65 years, respectively (range 16-89 years). Surgery was the primary treatment in 113 (78%) patients followed by radiotherapy in 81. Postoperative radiotherapy in doses of 64-66 Gy, where the intention was curative and delivered with either split course or not, was administered to a majority of patients after 1970. The split-course mode was practised between 1970 and 1989. The median follow-up time was 8.3 years for patients still alive. There were 57 (40%) relapses, of which 40 were local recurrences with 26 inside the treatment volume.

RESULTS

The overall 5-year survival was 53%. The majority of tumour-related deaths appeared in the first 3-5 years after diagnosis. Age, co-morbidity, the presence of lymph node metastases, adenoid cystic carcinoma and extent of disease were important for outcome; gender, however, was not. We found no difference in the survival between patients following split course therapy versus continuous fractionation. No difference could be seen in the survival of patients treated in the 1970s versus the 1990s.

CONCLUSIONS

Age, nodal engagement, a higher T-stage, adenoid cystic carcinoma histopathology, facial palsy and intercurrent disease worsen the outcome of patients, whereas gender does not. Treatment principles at our hospital have been surgery followed by radiotherapy since the early 1970s even though a split course technique was practised during a part of this period. Survival has not improved markedly. Thus, there is scope for improvement for this group of patients.