[Clinical characteristics and surgical management of primary intralabyrinthine tumor]

Objective: To analyze the clinical characteristics of primary intralabyrinthine tumors and to explore effective diagnostic and therapeutic strategies. Methods: A retrospective analysis was conducted on the clinical data of 41 patients with primary intralabyrinthine tumors diagnosed and treated at Shandong Second Provincial General Hospital (Shandong Provincial ENT Hospital) from August 2011 to December 2024. There were 16 males and 25 females, with a mean age of (49.6±11.4) years (mean±standard deviation); 20 cases occurred on the left side and 21 on the right side. All cases were diagnosed by high-resolution magnetic resonance imaging (HR-MRI), and 19 of them underwent surgical treatment, with the diagnosis confirmed by postoperative pathology. Imaging follow-up was performed for the surgical patients, and their clinical symptoms, imaging features, intervention methods, and therapeutic outcomes were summarized and analyzed. Results: Among the 41 patients, the most common symptom was hearing loss (39/41, 95.1%), followed by tinnitus (35/41, 85.4%), vertigo/dizziness (16/41, 39.0%), and ear fullness (15/41, 36.6%). The pure tone average (PTA) at 500, 1 000, 2 000, and 4 000 Hz was (97.1±29.0) dBHL. According to the WHO hearing loss classification, there were 1 case of mild hearing loss, 1 case of moderate hearing loss, 5 cases of moderately severe hearing loss, 5 cases of severe hearing loss, 5 cases of profound hearing loss, and 24 cases of total hearing loss. According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification, there were 1 case of Class A, 1 case of Class B, 2 cases of Class C, and 37 cases of Class D. Classification by tumor invasion site showed 24 cases of intracochlear type, 8 cases of vestibulocochlear type, 5 cases of transotic type (2 of which invaded the cerebellopontine angle), 3 cases of intravestibular type, and 1 case of transmodiolar type. For treatment modalities, 22 patients opted for follow-up observation, and 19 patients underwent surgical treatment (4 out of 5 transotic patients received staged surgery; 5 patients underwent simultaneous cochlear implantation; and 3 patients underwent tumor resection via the transcanal promontory approach under otoendoscopy). Postoperative pathological results revealed that 18 cases were schwannomas, and 1 case was neurofibroma. The follow-up duration for surgical patients ranged from 6 months to 10 years. Only 1 patient had residual tumor recurrence in the cochlea 3 years after surgery, and achieved complete recovery after reoperation; no recurrence was observed in the other surgical patients. Conclusions: Intralabyrinthine tumors are mainly characterized by hearing loss, most of which are sensorineural hearing loss of severe degree or above. Enhanced thin-slice MRI of the temporal bone is the most valuable imaging examination method. The treatment strategy can be either imaging follow-up or surgical intervention. The selection of surgical approach and whether to perform hearing reconstruction should comprehensively consider factors such as tumor size, invasion site, hearing status of the contralateral ear, and patient needs.