Cervical lymph node metastasis from squamous cell carcinoma of unknown primary origin: a case report

Abstract

Abstract: 

Carcinoma of unknown primary origin represents 3-5% of malignant tumours in adult patients, and is defined as the presence of an advanced carcinoma (with lymph node/distant metastases) with no evidence of a primary origin even after carrying out exhaustive diagnostic techniques. The histologic type that most frequently affects cervical lymph nodes is the squamous cell carcinoma, which usually presents as the metastasis or infiltration from a clinically occult oropharyngeal carcinoma, generally human papillomavirus (HPV)-positive, in which case they tend to have a better prognosis than their HPV-negative counterpart.

The objective of this presentation is to report the case of a cervical lymph node metastasis from squamous cell carcinoma that originated in the head and neck region, with no possible way of determining the specific location due to the lesion's clinical characteristics.

A 66-year old male patient with no known medical history consulted for trismus, weight loss and a left laterocervical mass over the prior 2 months. An ultrasound revealed multiple laterocervical lymphadenopathies. A fine needle aspiration was then performed, with the diagnosis of carcinoma. The diagnostic tests subsequently effectuated were unable to ascertain the lesion's possible primary origin.  Thereupon,  the lymph node conglomerate was excised and its examination exhibited a squamous cell neoplasm with positive p16 immunostaining.

According to recommendations of the College of American Pathologists in 2018, the confirmation of p16 reactivity in cases of cervical lymph node metastases from squamous cell carcinoma of unknown primary origin would aid in the distinction of an oropharyngeal primary tumour, as well as its association with the human papillomavirus, which carries prognostic value.