Acinic cell carcinoma of the parotid gland: Timeo Danaos et dona ferentes? A multicenter retrospective analysis focusing on survival outcome.

OBJECTIVES: To analyze the demographic data, surgical and adjuvant treatment data and the survival outcomes in adult patients affected by acinic cell carcinoma of the parotid gland (AciCC). METHODS: A retrospective multicenter analysis of patients treated for AciCC of the parotid gland from 2000 to 2021 was performed. Exclusion criteria were pediatric (0-18 years) patients, the absence of follow-up and patients with secondary metastatic disease to the parotid gland. Multivariable logistic regression was used to determine factors associated with survival. RESULTS: The study included 81 adult patients with AciCC of the parotid gland. The median age was 46.3 years (SD 15.81, range 19-84 years), with a gender female prevalence (F = 48, M = 33). The mean follow-up was 77.7 months (min 4-max 361, SD 72.46). The 5 years overall survival (OS) was 97.5%. The 5 years disease-free survival (DFS) was 60%. No statistical differences have been found in prognosis for age (< 65 or ≥ 65 years), sex, surgery type (superficial vs profound parotid surgery), radicality (R0 vs R1 + Rclose), neck dissection, early pathologic T and N stages and adjuvant therapy (p > 0.05). CONCLUSION: This study did not find prognostic factor for poorest outcome. In contrast with the existing literature, our results showed how also high-grade tumours cannot be considered predictive of recurrence or aggressive behaviour.

Management of Parapharyngeal Space Tumor Using Transoral Robotic Surgery: The Tonsillar Fossa Battlefield.

INTRODUCTION: The management of parapharyngeal space (PPS) tumors is surgical, but the approach remains a challenge. Attention should be paid to avoid intra-operative bleeding, cranial nerves damage, and external scars. PRESENTATION OF CASE: The authors report a case of a 23-year-old female, with complaint of progressive, painless swelling just below the right angle of the mandible of 6-month's duration. Magnetic resonance imaging images reported the presence of an oval-shaped expansive lesion (maximum diameter 3 cm), from the lower polar region of the parotid gland while fine needle aspiration cytology (FNAC) was not diagnostic. We performed a Trans Oral Robotic surgical excision of the tumors with Da Vinci Robot. DISCUSSION: Thanks to a detailed magnification, the authors were able to reach the PPS region through the tonsillar fossa saving the palatine tonsil without any significant bleeding or nerve lesions. The histological examination confirmed the diagnosis of pleomorphic adenoma of parotid gland. The decision on which surgical approach to be used is determined by site, size vascularity, histology of the tumor, and knowledge of radiological images. CONCLUSION: There is not only 1 surgical approach for PPS tumors but the surgeon must know all the different options and possible outcomes. Transoral Robotic Surgery approach with Da Vinci could represent a valid option with a good knowledge of Robot surgical instruments and a detailed preoperative plan.

A Retrospective Multicenter Italian Analysis of Epidemiological, Clinical and Histopathological Features in a Sample of Patients with Acinic Cell Carcinoma of the Parotid Gland.

BACKGROUND: The acinic cell carcinoma (AciCC) of the parotid gland is a rare tumor with an indolent behavior; however, a subgroup of this tumor presents an aggressive behavior with a tendency to recur. The aim of this multicenter study was to identify and stratify those patients with AciCC at high risk of tumor recurrence. METHODS: A retrospective study was carried out involving 77 patients treated with surgery between January 2000 and September 2022, in different Italian referral centers. Data about tumor characteristics and its recurrence were collected. The histological specimens and slides were independently reviewed by a senior pathologist coordinator (L.C.) and the institution's local head and neck pathologist. RESULTS: The patients' age average was 53.6 years, with a female prevalence in the group. The mean follow-up was 67.4 months (1-258, SD 59.39). The five-year overall survival (OS) was 83.2%. The 5-year disease-free survival (DFS) was 60% (95% CI 58.2-61.7). A high incidence of necrosis, extraglandular spread, lymphovascular invasion (LVI), atypical mitosis, and cellular pleomorphism was observed in the high-risk tumors compared to the low-risk ones. CONCLUSION: AciCC generally had an indolent behavior, optimal OS, DFS with few cervical node metastases, and rare distant relapses. This multicenter retrospective case series provides evidence of the need for clinical-epidemiological-histological stratification for patients at risk of poor outcomes. Our results suggest that the correct definition of high-risk AciCC should include tumor size, the presence of necrosis, extraglandular spread, LVI, atypical mitosis, and cellular pleomorphism.