(0654) Heads or Tails: Does Location of Paratid Mass Predict Likelihood of Malignancy?

Introduction: Most parotid masses are benign, however, rate of non-diagnosis on FNA remains significant (4-19%). Understanding features that suggest malignancy can guide prompt management. Here we examine clinical characteristics, including location of the mass within the parotid, and association with tumor pathology.

Methods: Consecutive adult patients undergoing parotidectomy between August 2018-September 2023 at a tertiary academic medical center were reviewed retrospectively. Patients with bilateral, recurrent, or non-primary parotid disease were excluded. Mass location was categorized as tail-of-parotid, body-of-parotid, or both based on preoperative physical exam; if exam insufficient, then imaging and operative notes aided categorization. Additional data included demographics, preoperative symptoms, greatest tumor dimension, and pathology. Analyses included frequency statistics and multivariate logistic regression.

Results: Of 341 patients, 129 met inclusion criteria (mean age at surgery 57 years, 47% female). At preoperative exam, 26 (20.2%) were symptomatic (e.g. pain, numbness, facial weakness, skin changes). Of the masses, 81 (62.5%) were located in the tail, 38 (29.5%) body, and 10 (7.8%) encompassing both body and tail (“both”). Overall, 35 (27.1%) masses demonstrated malignant final pathology. Masses in the tail were less likely to be malignant (p = 0.004). Malignant tumors were more often symptomatic (48.6% vs 9.6%, p < 0.001) and had larger greatest tumor dimension (3.9 vs 2.8 cm, p < 0.001). In multivariate regression, the odds of malignant pathology increased with the presence of preoperative symptoms (OR = 8.6 p < 0.001), location in the parotid body/both (OR = 3.6, p = 0.008), and larger tumor size (OR = 1.5, p = 0.009); gender and age did not have an effect.

Conclusions: In adults with primary presentation of unilateral parotid mass, presence of symptoms, location in the parotid body (vs tail), and greater tumor size independently increased the likelihood of malignant diagnosis. Improved understanding of characteristics that distinguish malignant parotid lesions is critical to ensuring expeditious management.