Patterns of computed tomography scan findings in patients with suprahyoid neck masses at the Moi Teaching and Referral Hospital

Abstract

Introduction: The neck is divided into two main portions; Suprahyoid Neck (SHN) and Infrahyoid Neck (IHN), each being sub-divided into various neck spaces. These spaces can be affected by congenital anomalies, infection, inflammations, neoplasms, vascular anomalies, and traumatic conditions. Establishing the location of a mass and the space of origin are invaluable steps in developing a differential diagnosis. The use of Computed Tomography (CT) can offer key information for better management of the patients with SHN masses. However, there is a paucity of data regarding its use in Sub-Saharan Africa (SSA). Pathologies of the neck region account for a sizeable proportion of the Ears, Nose and Throat (ENT) admissions in Kenya, with CT imaging done, and the results confirmed with Magnetic resonance imaging (MRI) or histopathological examination. However, in some of these cases, such confirmation is unnecessary if CT can reliably provide the needed diagnosis. But such practices are hindered by lack of data on the agreement between CT and histopathology. Objectives: The study sought to evaluate the types of neck masses of SHN observed on CT scan at Moi Teaching and Referral Hospital, assess their anatomical site, and compare CT diagnosis to histopathological examination results. Methods: Cross-sectional descriptive study was done among patients with SHN masses. Census was used with all the 123 patients with SHN masses presenting at the MTRH Radiology Department for the one-year study period, meeting the inclusion criteria included. CT imaging was done, and the images evaluated for size, location, contour, calcification, type of enhancement, necrosis, and fat planes with the adjoining structures, and other supplementary CT findings. For those where histopathology confirmation was done, histopathology results were abstracted. Descriptive analysis was used with mean and standard deviation used for continuous variables like age, while frequency and percentages were used for categorical variables. The differences in proportions and absolute numbers were used to compare CT and histological findings. The results are presented in the form of tables, CT images, and prose form. Results: Of the 123 patients, 80 (65.0%) were male. The mean age was 44.6 ±16.6 (SD) years. Of the 123 SHN masses, 38 (30.9%) were in the Pharyngeal Mucosal space, 26 (21.1%) parotid space, 13 (10.6%) retropharyngeal space, 13 (10.6%) poststyloid parapharyngeal space, 12 (9.8%) Masticator space, 7 (5.7%) Prestyloid parapharyngeal space, 7 (5.7%) prevertebral space, and one sublingual space. Among them, (55; 44.7%) were malignant, 27 (22.0%) benign, 25 (20.3%) infectious, 7 (5.7%) inflammatory, 6 (4.9%) congenital and 3 (2.4%) traumatic. Most, (60; 48.8%) had heterogeneous enhancement, 28 (22.8%) rim enhancement, and 22 (13.0%) homogenous enhancement. A total of 108 cases had histopathology examination done. There was agreement between CT and histopathology results in 99 (91.7%) cases. Conclusion: Malignant masses were observed to be the common etiologies in the suprahyoid neck spaces. CT findings showed high agreement with those of histopathological examination, hence an indicator that CT can be reliably used in most SHN masses' diagnosis. However, some cases necessitate further histopathological evaluation to provide more information where it is difficult to diagnose on CT. Recommendation: In evaluating the SHN masses, radiologists need to pay attention to the type of enhancement, margins, and presence of necrosis, key features that can aid in CT diagnosis. Multicenter and larger studies are needed to provide more evidence on the reliability, sensitivity and specificity of CT in the diagnosis of SHN masses.