A case report of rim enhancing lesion at the orbital apex

An unexpected case report of epidermoid cyst at the oculomotor nerve: mimicking a common cyst on MRI

Intracranial epidermoid cysts are benign lesions and are rarely seen in clinical practice. Owing to similarities in imaging findings to those of common cystic lesions, the preoperative diagnosis is rendered challenging. Here, we present a case report of an epidermoid cyst at the right oculomotor nerve, which was initially misdiagnosed as a common cyst. A 14-year-old female child was admitted to our department due to a previous magnetic resonance imaging scan of a cystic lesion on the right side of the saddle that was suspected to be an oculomotor nerve cyst. In our department, this patient underwent a complete surgical resection of the tumor, and the pathology results revealed an epidermoid cyst. This is the first study that reported an epidermoid cyst at the right oculomotor nerve entering the orbit, mimicking a common cyst in imaging. We hope that this study would allow clinicians to consider this type of lesion as a differential diagnosis. Moreover, we suggest that specific diffusion-weighted imaging scan should be performed to aid in the diagnosis.

Visual Outcomes After Endoscopic Endonasal Resection of Orbital Lesions

BACKGROUND

The endoscopic endonasal approach (EEA) has been increasing in popularity as an alternative to traditional transcranial and transorbital approaches in the treatment of orbital pathological entities. The purpose of the present study was to examine the outcomes of patients who had undergone EEA resection of orbital lesions at our center.

METHODS

We performed a retrospective medical record review of patients who had undergone the EEA for resection of orbital lesions and orbital apex decompression from January 1, 2006 to December 1, 2019. For all the patients, the demographic data, presenting symptoms, symptom duration, imaging data, operative details, and postoperative outcomes were collected and reviewed.

RESULTS

Nine patients underwent endoscopic endonasal resection of orbital lesions and orbital apex decompression at our center, including 6 male patients and 3 female patients. The mean age was 49.4 years, and the mean follow-up period was 3.8 years (range, 1-13.5 years). The orbital pathological lesions that were treated included nasopharyngeal carcinoma, hemangioma, fibrous dysplasia, IgG4 pseudotumor, inverted papilloma, angioleiomyoma, adenocarcinoma, and neuroendocrine paraganglioma metastasis. All the patients presented with exophthalmos of the affected orbit. Of the 9 patients, 5 presented with decreased visual acuity on examination. Postoperatively, 1 of these 5 patients had improved to baseline visual acuity, 3 had stable vision, and 1 had brief improvement before experiencing progressive visual decline 1 month postoperatively. Two patients presented with diplopia, and both improved postoperatively. Three patients experienced new, transient, and self-limiting postoperative diplopia.

CONCLUSIONS

For patients with orbital lesions causing compressive optic neuropathy, the endoscopic endonasal approach can be used as an alternative strategy in appropriately selected patients.