Adenoid cystic carcinoma (ACC) is the most common malignant salivary gland tumour of the maxillary sinus. The present study describes 24 cases seen over a period of 10 years at the Brazilian National Cancer Institute. Socio-demographic, clinical, pathological, and follow-up data were retrieved from the medical files for the period 1997–2006. The mean age of the patients was 51.1 years. Twenty-one (87.5%) presented advanced tumours. The main signs and symptoms found were a tumour mass (87.5%), pain (50%), nasal obstruction (25%), and epistaxis (20.8%). Most cases (62.5%) were treated with surgery and radiation therapy. Follow-up data showed two patients (8.3%) with residual disease, local recurrences in four (16.7%) patients, and distant metastasis in five (20.8%). The overall 5- and 10-year survival rates were 72.61% and 62.11%, respectively. Maxillary sinus ACC has an aggressive but indolent behaviour, typically presenting at an advanced T stage that reflects a poor prognosis for patients.
Adenoid cystic carcinoma (ACC) is the most common malignant salivary gland tumour in the maxillary sinus and sino-nasal tract in general. It also constitutes the second most common non-squamous malignancy affecting the maxillary sinus, accounting for 45–60% of all cases of non-squamous malignancy at this location.
Clinically, maxillary sinus ACC (MSACC) has a slow but not indolent behaviour and is associated with local recurrences, late metastasis, and long-term death. Pain, nasal obstruction, and epistaxis are the most frequent complaints and symptoms become worse as the tumour grows.
MSACC, as with ACC of the minor salivary glands, tends to behave more aggressively than its counterparts in the major salivary glands or minor salivary glands in other locations. Therefore, treatment usually relies on a combination of different modalities, especially surgery and radiation therapy, and even so the prognosis remains poor.
Only a few series of MSACC have been described over the past 40 years and conclusive information regarding the clinical and behavioural characteristics of these tumours are relatively lacking in the literature. This is reinforced by the fact that MSACC has been studied as part of a major sample of sino-nasal carcinomas, making the interpretation of its individual characteristics difficult. The present study aimed to describe 24 cases of ACC affecting the maxillary sinuses, all diagnosed during a 10-year period at a single institution in Rio de Janeiro, Brazil.
Patients and methods
All cases of maxillary sinus malignancy occurring during the period 1997 through 2006 were retrieved from the files of the head and neck surgery department of a single institution. Only cases in which the maxillary sinus was shown to be the epicentre of the tumour, as confirmed in the surgical registers, on imaging examination, and/or on pathological analysis, were included in this study. Cases in which an antral origin could not be established completely, as well as those that were not diagnosed at the study institution, had incomplete files, or were identified as metastatic to the maxillary sinus, were excluded from the study.
All cases were confirmed histologically in accordance with the latest World Health Organization (WHO) classification of salivary gland tumours, based on routinely stained tissue sections. The histological diagnoses of the cases included in this study were revised by three of the authors (MFA, ALAE, AML), two of whom are general pathologists and the other an oral pathologist. Tumours were clinically re-staged in accordance with Sobin and Wittekind’s UICC TNM Classification of Malignant Tumours, for nasal and paranasal sinus tumours.
The following data were collected and reviewed: demographic (age, sex, smoking, and alcoholism), clinical (site of origin, size of the tumour, complaints, signs and symptoms, and TNM classification), pathological (histological diagnoses and classification, presence of residual disease, and local recurrence or distant metastasis), imaging (computed tomography (CT) or magnetic resonance imaging (MRI)), and follow-up; the results were described and analyzed. Follow-up was calculated as the time from the first appointment at the institution for the primary sinus tumour to the date of either the last contact (lost patient) or death. All cases were followed up for a minimum of 5 years (patients diagnosed in 2006) or until recurrence or death; the maximum period of follow-up was 16 years.
Overall survival curves for different clinico-pathological factors were constructed using the Kaplan–Meier method and compared by the log-rank test and Cox proportional hazard model. A P -value of less than 0.05 was considered significant. The statistical analysis was conducted using Stata statistical software, version 10 (StataCorp LP, College Station, TX, USA).
This study was approved by the institutional committee on human research and was conducted and developed in accordance with international rules for ethics in research.