Histological Assessment of the Carotid Sheath in Patients With Oral Squamous Cell Carcinoma

Abstract

Purpose: During surgical management of the neck using various types of neck dissection, the carotid sheath is removed, in particular, the part adjacent to the jugular lymph node chain, with the intention of preventing recurrence from the lymphatics present within it. The role of the carotid sheath as a potential origin for nodal recurrence has not been proved thus far. Working in a tissue plane between the carotid sheath and the neurovascular structures of the neck can lead to a greater chance of damage to these structures. Also, the carotid sheath is a strong fibroelastic tissue barrier that shields the internal jugular vein and carotid artery from saliva and local infection during the postoperative period. Thus, this study investigated the histopathology of the carotid sheath in patients with oral squamous cell carcinoma (OSCC) and assessed the pathologic infiltration of the carotid sheath when grossly uninvolved.

Patients and methods: Pathologic infiltration and histopathologic characteristics of the entire length of the carotid sheath were assessed in 30 biopsy-proved cases of OSCC; these patients underwent surgical excision of the lesion in addition to neck dissection from 2013 to 2015 in the craniofacial unit of the authors' institution.

Results: The carotid sheath consisted of fibrofatty tissue and interspersed nerve bundles. Neutrophilic infiltration and dilated lymphatic channels were seen in all 30 cases. Miniature lymph nodes adherent to the carotid sheath were seen in 5 cases and some lymphoid aggregates were seen in 15 cases. The carotid sheath in all 30 cases (metastatic and nonmetastatic) was free from tumor deposit and lymphatic tumor emboli, which are indicators of tumor cell infiltration.

Conclusion: Indicators of tumor cell infiltration were not found in any of the 30 cases. The result did not vary with the age or gender of the patient, tumor size, location, staging or grading of the tumor, or even when there were metastatic lymph nodes in the gross specimen. Hence, the role of the carotid sheath as a potential origin for nodal recurrence is questionable and its removal needs reconsideration.