OBJECTIVETo investigate the value of narrow band imaging (NBI) endoscopy in the detection of unknown primary tumor site with cervical lymph node metastases of squamous cell carcinoma.

METHODSFifty-three patients with cervical lymph node metastases of squamous cell carcinoma treated in our department between June 2009 and December 2011 were enrolled in this study. Their primary tumor site was not detected by routine computed tomography, magnetic resonance imaging and laryngoscopy. The nasopharyngolarynx was examined by NBI endoscopy to explore the primary tumor site.

RESULTSA total of 53 cases with cervical lymph node metastasis of squamous cell carcinoma from an unknown primary were examined under NBI endoscopy. The primary tumor site was confirmed by NBI examination in 47.2% (25/53) of patients, significantly better than routine radiology and endoscopy (0, P < 0.001). These primary tumors were small and superficial, with characteristic mucosal vascular morphologies. The superficial nasopharyngeal carcinomas under NBI examination showed the superficial thin branch-like or torturous line microvessels. The notable characteristics of the squamous cell carcinoma of oropharynx, hypopharynx and larynx was the well demarcated brownish area and scattered brown dots.

CONCLUSIONThe NBI endoscopy can provide better visualization of the morphology of superficial mucosal vasculature and improve the ability to detect possible primary cancer in patients with primary unknown cervical lymph node metastasis.