Exploring potential treatment opportunities in a head and neck tumor patient with AdCC: A novel germline ERCC2 mutation case report.

rationaleAdenoid cystic carcinoma (AdCC) is an invasive head and neck malignancy characterized by unpredictable growth, extensive perineural invasion, a high rates of metastasis, and poor survival rates. Genetic alterations, including MYB-NFIB and MYBL1-NFIB fusions, and mutations within the Notch signaling and DNA damage repair pathways, have been identified. PATIENT CONCERNS: A 58-year-old female presented with a space-occupying lesion of the anterior cranial fossa floor during a physical examination and sought further consultation in July 2022.In our case, a 58-year-old woman was incidentally found to have an anterior cranial fossa lesion during a routine physical examination, which was subsequently confirmed as AdCC following postoperative immunohistochemistry. DIAGNOSES: Based on these imaging and histopathological findings, a diagnosis of AdCC was established. Integrating the genetic test results, the case was diagnosed as MYB or MYBL1 fusion-negative AdCC. This case report highlights a rare molecular signature of ERCC2 and BRCA2 inactivation in AdCC, in the absence of MYB or MYBL1 fusions.

interventionsThe patient underwent postoperative radiotherapy (RT) to the primary site approximately 2.5 months postsurgery. The concurrent presence of germline ERCC2 and somatic BRCA2 mutations offers novel insights into potential treatment strategies for this rare malignancy. OUTCOMES: To date, no recurrence has been observed during follow-up. LESSONS: We found a novel germline ERCC2 mutation and somatic BRCA2 mutation in a patient with AdCC. Our findings expand the molecular landscape of rare MYB or MYBL1 fusion-negative AdCC patients and provide a potential therapeutic strategy for this rare head and neck tumor.