Cystic form of cervical lymphadenopathy in adults. Guidelines of the French Society of Otorhinolaryngology (short version). Part 2-etiological diagnosis procedure: Clinical and imaging assessment.

Introduction: The authors present the guidelines of the French Society of Otorhinolaryngology (SFORL) for clinical and radiological assessment of cystic neck lymphadenopathy of unknown primary in adults. Most cases concern head and neck carcinoma metastasis, often in the oropharyngeal area, or less frequently differentiated thyroid carcinoma or non-keratinizing nasopharyngeal carcinoma.

Methods: A multidisciplinary task force was commissioned to carry out a review of the literature on the etiological work-up in cystic neck lymphadenopathy in adults: clinical examination, conventional imaging (ultrasound, CT, MRI) and metabolic imaging. Guidelines were drafted based on the articles retrieved, and graded A, B, C or expert opinion according to decreasing level of evidence.

Results: Oriented clinical examination, cervical and thyroid ultrasound scan and contrast-enhanced neck and chest CT scan are recommended in the assessment of cystic neck lymphadenopathy of unknown primary in adult patients. PET-CT is recommended prior to panendoscopy, to identify the primary tumor.

Conclusion: Clinical and radiological assessment is fundamental for etiologic diagnosis of cystic neck lymphadenopathy in adult patients, and should be completed by cytological examination before in initiating treatment.