Neck Mass Came Back Cancer... Now What?

It is not uncommon that an adult patient presents with a neck mass to an ENT clinic. Unfortunately, upon workup which typically includes a needle biopsy, the neck mass comes back showing cancer, usually, a type of cancer called squamous cell carcinoma, although lymphoma, mucoepidermoid carcinoma, etc occasionally occurs as well. In this blog article, we will focus specifically on the case of the neck mass being squamous cell carcinoma.

At this point, the patient's main concern is what's next? This situation medically is known as cervical metastasis from squamous cell carcinoma of unknown primary (SCCUP) origin. 

The most important part of treatment is finding the primary source of this cancer such that it is no longer an "unknown primary." The neck mass itself is not the "source," rather it is the result of a cancer found somewhere else in the throat region; it metastasized from somewhere else. The most common primary source of head and neck squamous cell carcinoma with an unknown primary is the tonsil and base of tongue although the cancer can literally occur from any part of the lining of the voicebox, mouth, and back of nose.

Why is it important to (try) and find the primary?

It's because subsequent definitive cancer treatment with surgery, radiation, and chemotherapy can be more focused and therefore less intense with less side effects. If the primary cancer location is not able to be identified, then treatment with radiation and even chemotherapy requires a wide area of treatment extending from the nose and down to the voicebox region with consequent significant side effects affecting this wide region (radiation burn, trouble swallowing, loss of taste/smell, dental damage, etc).

In the effort to find the primary cancer in order to avoid such a wide field of treatment (beyond nasal endoscopy and a careful physical exam), directed biopsies are performed under general anesthesia which more recently would also include bilateral tonsil removal (if tonsils are still present).  

This situation is one of those in which you definitely WANT the biopsy to come back showing cancer as that would mean the primary site has been identified and subsequent treatment can be de-intensified resulting in less side effects.

If the neck mass is only on one side, why are both tonsils removed? It's because studies have shown that the primary cancer site occurs up to 10% of the time from the side opposite the neck mass!

References:

Role of palatine tonsillectomy in the diagnostic workup of head and neck squamous cell carcinoma of unknown primary origin: A systematic review and meta-analysis. Head Neck. 2019 Apr;41(4):1112-1121. doi: 10.1002/hed.25522. Epub 2018 Dec 21.

Prevalence of synchronous bilateral tonsil squamous cell carcinoma: A retrospective study. Clin Otolaryngol. 2018 Feb;43(1):1-6. doi: 10.1111/coa.12981. Epub 2017 Sep 25.

Investigation and management of the unknown primary with metastatic neck disease: United Kingdom National Multidisciplinary Guidelines. J Laryngol Otol. 2016 May;130(S2):S170-S175.