Biopsy of parotid masses: Review of current techniques

Abstract

Definitive diagnosis of parotid gland masses is required optimal management planning and for prognosis. There is controversy over whether fine needle aspiration cytology (FNAC) or ultrasound guided core biopsy (USCB) should be the standard for obtaining a biopsy. The aim of this review is to assess the current evidence available to assess the benefits of each technique and also to assess the use of intra-operative frozen section (IOFS). Literature searches were performed using pubmed and google scholar. The literature has been reviewed and the evidence is presented. FNAC is an accepted and widely used technique. It has been shown to have variable diagnostic capabilities depending on centres and experience of staff. USCB has a highly consistent diagnostic accuracy and can help with tumour grading and staging. However, the technique is more invasive and there is a question regarding potential for seeding. Furthermore, USCB is less likely to be offered as part of a one-stop clinic. IOFS has no role as a first line diagnostic technique but may be reserved as an adjunct or for lesions not amenable to percutaneous biopsy. On balance, USCB seems to be the method of choice. The current evidence suggests it has superior diagnostic potential and is safe. With time, USCB is likely to supplant FNAC as the biopsy technique of choice, replicating that which has occurred already in other areas of medicine such a breast practice.

Keywords: Parotid, Biopsy, Fine needle aspiration cytology, Mass, Fine needle aspiration, Cytology, Core-biopsy, Ultrasound, Diagnosis

Core tip: Definitive diagnosis of parotid gland masses is important for management and prognosis. There is a move toward a triple assessment but there remains some uncertainty about the best method for obtaining biopsy. We discuss the advantages and disadvantages of each technique and propose that ultrasound guided core biopsy should be the technique of choice. Fine needle aspiration cytology is an accepted and widely used technique although the diagnostic accuracy is low. Intra-operative frozen section does not have a role as a first line diagnostic technique but may be reserved as an adjunct or for lesions not amenable to percutaneous biopsy.