Diagnostic approaches to carcinoma of unknown primary of the head and neck

Abstract

Squamous cell carcinoma in cervical lymph nodes arising from an undetected primary tumour, termed carcinoma of unknown primary (SCCUP), accounts for 2.0%-5.0% of all head and neck cancers (Strojan et al., 2013;Waltonen et al., 2009). The most common presentation is an enlarged cervical lymph node with carcinoma identified by needle biopsy, without evidence of a primary tumour on physical examination or imaging. SCCUP is a common clinical presentation for patients with human papillomavirus-mediated oropharyngeal cancer (HPV + OPSCC), as patients with HPV + OPSCC are more likely to present with small primary tumours and more advanced nodal disease (Stenmark et al., 2017). Given the rising incidence of HPV + OPSCC in many countries (Chaturvedi et al., 2011;Sturgis & Cinciripini, 2007), there is likely to be an increasing number of patients who present with SCCUP. Meticulous work-up of the SCCUP patient is central to the management of these patients as identification of the primary site improves overall survival and allows for definitive oncologic resection or more focused radiation when indicated (

Updates in the management of unknown primary of the head and neck

“…A primary tumor is often difficult to detect on physical examination, but small primaries can sometimes be identified using distal chip flexible laryngoscopy. Flexible endoscopy with narrow band imaging (NBI) is a new technology that highlights neo-angiogenesis to provide superior visualization of mucosa compared to standard endoscopy ( 2 , 12 ). Studies report successful primary detection using NBI in SCCUP cases where traditional workup did not localize a primary site, with a pooled detection rate of 35%, sensitivity of 83%, and specificity of 88%.…”

“…Studies report successful primary detection using NBI in SCCUP cases where traditional workup did not localize a primary site, with a pooled detection rate of 35%, sensitivity of 83%, and specificity of 88%. ( 2 , 13 ) Ebisumoto et al. ( 14 ) specifically demonstrate increased detection of HPV-related oropharyngeal primary tumors when using transoral NBI endoscopy, highlighting its non-invasiveness and feasibility in outpatient settings.…”

“…Another study reports accuracy, sensitivity, and specificity values of CNB as 94%, 92% and 100%, respectively ( 18 ). CNB is also useful in additional histopathological analysis, such as determining p16 or HPV status ( 2 ).…”

“…Some studies suggest that excisional biopsies result in a “violated neck” which may be associated with wound compilations and higher recurrence ( 19 ), although this has not been uniformly reported ( 20 , 21 ). If proceeding with excisional biopsy, the surgeon must be prepared to perform a complete neck dissection if pathology demonstrates carcinoma ( 2 ).…”

Rare cancers and cancer of unknown primary: Here's what you should know!

“…The only consistent, but not statistically significant, association observed was a moderately increased CUP risk in participants who reported a sibling with cancer compared to those who did not. Ye et al (2021) addressed head and neck cancers, specifically squamous cell carcinoma in cervical lymph nodes arising from an undetected primary tumour (SCCUP), in their commentary. Moreover, they emphasise that clinicians who treat head and neck cancer patients should be familiar with diagnostic approaches to SSCUP, and they highlight several techniques.…”