Primary Adenoid Cystic Carcinoma of the Frontal Sinus: Case Description of a Previously Unreported Entity and Literature Review

Clinical Characteristics and Long-Term Outcomes following Surgery Combined with Adjuvant Radiotherapy for Patients with Frontal Sinus Malignancies

Objectives  Primary frontal sinus malignancies (FSMs) are the rarest sinonasal cancers. This study aimed to determine clinicopathologic characteristics of primary FSMs and provide long-term survival outcomes. Design  This study is a retrospective review. Setting  The study was conducted at a tertiary medical center. Participants  Patients who participated in this study were diagnosed with primary FSMs. Main Outcome Measures  Median survival time is the primary outcome measure of this study. Results  In this series, the median age was 48 years (30-53 years) and all patients were male. There were five cases with squamous cell carcinoma and one with osteosarcoma. All cases presented with locally advanced disease without regional lymphatic metastasis, including five cases of stage III and one case of stage II. The two most common pathways of tumor invasion were as follows: local tumor broke posteriorly through bone wall and invaded dura mater, followed by frontal lobe; local tumor infiltrated downward through the floor of frontal sinus into ethmoid sinus, thereafter invaded laterally orbit and orbital contents. All patients received surgery followed by postoperative radiotherapy at the total doses of 50 to 75.95 Gy. Among them, only one patient underwent R0 resection, the rest of patients underwent R1/R2 resection. With a median survival time of 56 months (32-76 months), two patients receiving R1/R2 resection developed treatment failure and died within 5 years, including one case with local recurrence and one with local recurrence, thereafter distant metastasis. Conclusion  The majority of FSMs presented with peripherally invasive progression lesions which led to a high ratio of R1/R2 resection. Surgery combined with postoperative radiotherapy might result in satisfactory efficacy.

Sinonasal Malignancies Involving the Frontal Sinus: A Mono-Institutional Experience of 84 Cases and Systematic Literature Review

Frontal sinus involvement by malignant tumors is a rare finding. Therefore, a systematic literature review along with a personal case series may contribute to defining more accurately the epidemiology, treatment options, and outcomes of these neoplasms. This is a retrospective review of patients affected by frontal sinus malignancies surgically treated in a tertiary-care referral center over a period of 20 years. Moreover, a systematic literature review of studies describing frontal sinus cancers from 2000 to date was performed according to PRISMA guidelines in order to analyze current evidence about the treatment and outcomes of such a rare disease. Our retrospective review was basedon 84 cases, treated with an exclusive endoscopic approach in 43 cases (51.2%), endoscopic approach with frontal osteoplastic flap in 6 cases (7.1%), and transfacial or transcranial approaches in 35 cases (41.7%). The five-year overall, disease-specific, disease-free, and recurrence-free survivals were 54.6%, 62.6%, 33.1%, and 59.1%, respectively. Age, dural involvement, type of surgical resection, and surgical margin status were significantly associated with the survival endpoints. In conclusion, the involvement of the frontal sinus is associated with a poor prognosis. Multidisciplinary management, including specific histology-driven treatments, represents the gold standard for improving outcomes and minimizing morbidity.