Accuracy of Diagnostic Methods for Detection of Head and Neck Primary Origin in Metastatic Neck Mass

Abstract

Background and Objectives It is important to localize the primary site when cervical lymph node metastasis is detected. The purpose of this study was to evaluate the accuracy of diagnostic methods to detect the head and neck primary site in patients with metastatic neck mass. Subjects and Method Sixty-six patients who had presented with neck mass and were confirmed to have metastatic carcinoma by fine needle aspiration cytology from January 1998 to June 2016 were enrolled. We analyzed the accuracy of diagnostic modalities that inluded physical and endoscopic examination, CT, MRI, PET/CT, and guided biopsy. Results The mean age of patients was 58.7±12.6 years with the male to female ratio of 55:11. The metastatic lymph nodes were most common at level II (60/66, 90.9%) followed by levels III, IV, I and V. The most common primary site was tonsil (45.5%), followed by the nasopharynx, base of tongue and hypopharynx, and eight patients (12.1%) were diagnosed as metastatic carcinoma of unknown origin. The primary sites were detected by: physical and endoscopic examination in 36/66 (54.5%), CT in 41/66 (62.1%), MRI in 39/52 (75%) and PET/CT in 46/63 (73.1%). The primary sites were additionally detected using PET/CT for nine cases of the 20 cases, where primary sites were not found using physical and endoscopic examination, CT or MRI. Guided biopsy was done in 11 cases, where primary sites were not detected by all of the methods; hence, primary sites for 3 cases were additionally revealed. Conclusion PET/CT is a useful method when physical examination, CT and MRI cannot reveal the primary site of metastatic neck mass. Guided biopsy can be performed when primary site is not founded by any of the physical and imaging examinations. Key words: Diagnosis ㆍ Guided biopsy ㆍ Head and neck cancer ㆍ Metastatic neck mass ㆍ Unknown primary tumor