[Cyto-histological correlation in the management of parotid gland tumors: A retrospective study of 160 cases]

A Cautionary Tale: A Case Report Describing a Benign Parotid Oncocytoma Diagnosed as Metastatic Squamous Cell Carcinoma on Fine Needle Aspirate

Parotid oncocytoma is a rare salivary gland tumour. Management does not require surgical intervention if diagnosed on a preoperative biopsy. A 64-year-old man presented with a parotid mass diagnosed as mcSCC on fine-needle aspiration cytology (FNAC). Surgical histopathology following parotidectomy demonstrated an oncocytoma of the parotid gland. Parotid oncocytomas are rare; therefore, diagnosis can be difficult. An MRI, CT, and US-guided biopsy are required for diagnosis. Ultrasound-guided core biopsy (UGSB) is more sensitive and specific when compared to FNAC for diagnosing malignant tumours. Diagnoses of benign salivary gland tumours on biopsy remain challenging. The aim of this article is to highlight the difficulty of diagnosing salivary gland tumours. We further aim to outline the contributing features that lead to this misdiagnosis and suggest steps to circumvent it in the future. This report describes the challenges in diagnosing salivary gland tumours and outlines the contributing features of this misdiagnosis. We add to the literature an additional case of a parotid oncocytoma.

[Performance of the magnetic resonance imaging in parotid gland tumor histopathology]

Introduction

salivary gland tumors mainly occur in the parotid gland. These tumors are rare but are characterized by histological heterogeneity, thus posing diagnostic challenges. Magnetic resonance imaging (MRI) is currently the most reliable imaging test for the evaluation of these tumors. The purpose of this study was to highlight the diagnostic value of MRI and its role in parotid gland tumor histopathology.

Methods

we conducted a retrospective descriptive and analytical study of 50 patients with parotid gland tumor, operated and treated in the ear, nose and throat (ENT) Department and in the Department of cervicofacial surgery at the Tahar Sfar University Hospital of Mahdia between 2001 and 2019. All patients underwent preoperative MRI of the parotid gland.

Results

out of 50 patients included in the study, 36 (72%) had benign tumor and 14 (28%) malignant tumor. The sensitivity of MRI for the diagnosis of malignant tumor was 92.8% with a specificity of 97.2%, a negative predictive value of 93% and a positive predictive value of 97%. With respect to benign tumor characterization, MRI suggested the diagnosis of Warthin tumor in all cases (13 cases) and of pleomorphic adenoma in 22 out of 23 cases. There were two diagnostic errors: MRI suggested the diagnosis of pleomorphic adenoma instead of adenoid cystic carcinoma in one case and of malignant tumor instead of pleomorphic adenoma due to diffusion restriction.

Conclusion

MRI is highly efficient in the assessment of parotid tumor histology and, especially, after the advent of new functional sequences. However, only histological examination allows to confirm with certainty the diagnosis.

[Ultrasound-guided minimally invasive diagnostics and treatment in the head and neck area]

Tumoral lesions in the head and neck region represent a diagnostic and therapeutic challenge in otorhinolaryngologic routine. High-resolution ultrasound is usually able to guide diagnosis. Nevertheless, a definite differentiation between benign and malignant lesions can only be achieved by tissue biopsy. The various options for obtaining samples for histopathological or cytological examination-from minimally invasive ultrasound-guided fine-needle biopsy to punch biopsy and open surgical biopsy-will be discussed in the first part along with the associated advantages and disadvantages. In the second part of this CME article, minimally invasive ultrasound-guided therapeutic options in the head and neck region which can be performed on an outpatient basis are depicted.