Four distinct ipsilateral vestibular schwannomas: A case of mosaic NF2-related schwannomatosis.

OBJECTIVES: Distinguishing between sporadic and germline/mosaic NF2-related schwannomatosis is important to ensure that patients have appropriate long-term care. With this report, we describe a unique case of a patient with 4 ipsilateral schwannomas and identify a combination of sequencing modalities that can accurately diagnose mosaic NF2-related schwannomatosis. METHODS: We present a 32-year-old woman with a familial history of vestibular schwannoma in her father and right-sided schwannomas involving the apical and basal turns of cochlea, lateral semicircular canal, and internal auditory canal (IAC). Genetic analysis of blood and frozen tissue from 2 tumors (intralabyrinthine and IAC tumors) was performed using next-generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), and optical genome mapping (OGM). RESULTS: Germline testing for NF2, LZTR1, and SMARCB1 was negative. Tumor genetic testing revealed a shared NF2 pathogenic variant between the 2 tumors ("first hit") but distinct "second hit" NF2 variants, including mosaic loss of chromosome 22 in the IAC tumor seen only with OGM, consistent with mosaic NF2-related schwannomatosis. CONCLUSIONS: Multimodality sequencing, including NGS, MLPA, and OGM, was required to ensure appropriate diagnosis of mosaic NF2-related schwannomatosis in this patient. A similar approach can be used for other patients with multiple ipsilateral tumors and suspected tumor predisposition.

In-office Transoral Hilar Sialolithotomy: A Cost-Effective and Patient-Centered Procedure.

Transoral sialolithotomy performed in-office under local anesthesia is routinely performed for distal submandibular stones. We demonstrate the senior author's novel practice of in-office transoral sialolithotomy for hilar and intraglandular stones. A review of cases performed by the senior author revealed similar rates of complication and stone recurrence as those reported in the literature from removal under general anesthesia. Laryngoscope, 134:4042-4044, 2024.

Confirmatory Auditory Brainstem Responses Testing Results in Discordant Outcomes: Implications for Timely Care.

OBJECTIVES: The purpose of this study is to evaluate for discrepancies in diagnostic auditory brainstem responses (ABR) between Children's National Hospital (CNH), a pediatric medical center, and outside facilities (OSF) that referred patients to CNH for confirmatory evaluation. Such discrepancies impact early hearing detection and intervention (EHDI) timelines. METHODS: A retrospective chart review was conducted from an internal database of patients who underwent diagnostic ABR from 2017 to 2021. Only patients with ABR results from both CNH and OSF were analyzed. Demographic data, external and internal test results, and intervention data were obtained. Hearing loss (HL) severity was graded on a scale of 0 to 8, where 0 indicated normal hearing and 8 indicated profound. Each ear was analyzed separately. RESULTS: Forty-nine patients met the inclusion criteria, and each ear was evaluated separately. Median HL severity was 1.0 [0.0, 4.3] at CNH compared to 3.0 [1.8, 6] at OSF (p = 0.004). Forty-seven ears (48.0%) showed lower severity at CNH. Twenty-seven patients (55%) received hearing amplification devices. The median age at time of hearing intervention was 220 days. CONCLUSION: Our results showed statistical significance in the median severity of HL between CNH and OSF. A substantial proportion (70%) of children in our dataset who received amplification via cochlear implant or hearing aids were shown to have discrepancies in ABR findings from CNH and OSF. These findings have implications with regards to the appropriate usage of health care resources and maintaining EDHI timelines. LEVEL OF EVIDENCE: 4 (Retrospective Cohort Study) Laryngoscope, 133:3571-3574, 2023.