The role of fine needle aspiration biopsy in deep lobe parotid tumors: Comparison of preoperative cytology and postoperative histopathologic results.

PURPOSE

Major salivary gland tumors constitute almost 3% of head and neck tumors. Tumors located exclusively in the deep lobe are not common and 20% of parotid gland tumors originate from deep lobe under the branches of the facial nerve. Accuracy of fine needle aspiration biopsy (FNAB) procedure in salivary gland tumors have been studied extensively, however there isn't any data regarding usefulness of FNAB in tumors located exclusively in deep lobe of parotid gland. In this study we aimed to assess the use of FNAB in deep lobe parotid tumors.

MATERIALS AND METHODS

We retrospectively analyzed 51 patients with deep lobe parotid tumors who underwent surgery in our clinic between January 2013-December 2018. Characteristics of patients were recorded. Preoperative FNAB results and postoperative final histopathologic diagnosis were compared. Statistical analysis was performed using SPSS 24.0 was used for statistical analysis.

RESULTS

The number of patients that met the inclusion criteria was 51. The mean age of patients were 49.2(14-86). In 40 (78.4) of the patients, tumor was reported as benign and in 11 (21.6) patients FNAB diagnosis was suspicious for malignancy, malignant or non-diagnostic. In final histopathologic diagnosis, 42 of the tumors were benign and 9 were malignant. The most common benign tumor type was pleomorphic adenoma which constitutes 27 of the cases (52.9%). Regarding detection of malignant disease, the sensitivity of FNAB was 90.4%, specificity was 77.7%, positive predictive value was 95%, negative predictive value was 63.6%. There was a substantial agreement between FNAB and final histopathologic diagnosis(kappa = 0,628).

CONCLUSIONS

FNAB is a safe and reliable tool to evaluate deep lobe parotid tumors. It is an important part of preoperative surgical planning and can help the surgeon in patient counseling. FNAB with ultrasound guidance is recommended for deep lobe tumors.