Differential diagnosis of a mass in the upper lateral neck
Authors: Solem B. S. , Schrøder K. E. , Mair I. W. S. 
Published: November 2007

The differential diagnoses and the duration of symptoms are presented for a group of 288 patients encountered over a ten-year period with a mass in the region of the neck behind and below the angle of the mandible. While infections constituted the largest aetiological group (48·3 per cent), 109 cases (37·9 per cent) had some form of neoplasia, with malignancy being found in 48 (16·6 per cent). The duration of symptoms varied widely, only the acute infections having an acceptably short delay prior to hospital admission. The mean symptom duration for all the neoplastic cases was in excess of five months.

The patient with a lump in the neck is a frequently encountered problem in ear, nose and throat practice. An important precept, which has long been recognized in the literature, is that any persistent asymmetrical mass in the neck of an adult must be regarded as malignant until definite proof to the contrary is obtained (Martin and Romieu, 1952; Slaughteret al., 1956; Skolniket al., 1965; Shaw, 1976). Differential diagnostic possibilities in all age groups are however numerous, and pre-operative conclusions must often be revised following histopathological examination. A simple and rational approach, which is frequently of considerable value in the clinical assessment of these patients, is a combination of topographical and temporal classifications.

In 1960, Skandalakiset al.proposed a rule-of-7, in which the average duration of symptoms for cervical masses caused by infections was 7 days; for neoplasms, 7 months; while an interval of 7 years was characteristic of developmental anomalies. The topographical approach involves subdividing the neck into anatomical regions. The most posterior area, covered by the trapezius muscle is, in this context, of minimal clinical interest, since the overwhelming majority of neck masses lies anterior to this muscle. The clinically important part of the neck is subdivided into the anterior and posterior triangles by the sternocleidomastoid muscle. The posterior triangle is much less frequently the site of a neck mass, although malignancy is relatively more common in this region (Moussatos and Baffes, 1963). The anterior triangle is further subdivided by the digastric and omohyoid muscles into four smaller triangles, readily recognizable in the living neck, since both muscles are attached to the hyoid bone which can be palpated in the vast majority of cases.

The thyroid and submandibular glands are the most frequent source of neck masses in the inferior carotid, or muscular, and the digastric triangles respectively, and involvement of these organs can usually be readily recognized in the clinic (Beahrs, 1955; Slaughteret al., 1956; Skandalakiset al., 1960). The small submental triangle contains few structures of importance, and the majority of swellings in this region are either thyroglossal cysts or enlarged lymph nodes.

The situation is radically different in the carotid triangle, the region of the neck posterior and inferior to the angle of the mandible, where a wide variety of anatomical structures is congregated, and the differential diagnostic possibilities are consequently greater. The present study is a review of swellings in the neck confined to this area.