Conservative or surgical management of orbital schwannomas: a population-based case series.

INTRODUCTION: Orbital schwannomas (OS) are rare occurrences with no more than 500 cases reported in the literature. The tumor's potential to compromise the delicate neuro-ophthalmic structures within the orbit prompts surgical removal. Tumor removal is performed by ophthalmologists, often requiring a multidisciplinary surgical approach. The literature contains a very limited number of cases managed non-surgically. However, the inherent risks of orbital surgery warrant a comparison of the outcomes of conservative and surgical management strategies. AIMS: To review the national Swedish experience with the management of orbital schwannomas. METHODS: The study center is the primary Swedish referral center for the multidisciplinary management of orbital tumors, including schwannomas. During the period of 2005 to 2021, 16 patients with an OS diagnosis were managed at the center. RESULTS: Four patients initially underwent surgery where gross total resection (GTR) was achieved in three (75%) and subtotal resection (STR) in one (25%) case. The remaining 12 patients, who had a low risk of neuro-ophthalmic impairment, were managed conservatively with radiological and clinical examinations at regular intervals. After an average follow-up of 17 months, surgery was performed in three of these cases (25%). No recurrences or tumor growths were detected on radiological follow-ups (mean 50 months), and all patients experienced postoperative improvement at clinical follow-up (mean 65 months). The remainder of the conservatively treated patients (n=9) experienced no clinical progression (mean 30 months). A slight radiological tumor progression was detected in one patient after 17 months. CONCLUSION: There were no differences in long-term outcome between patients who had been managed with early surgery and those operated later after an initially conservative management. Conservatively treated patients had minimal to no symptoms and remained clinically stable throughout the follow-up period. Based on these findings, conservative management may successfully be adopted in cases with mild symptoms, no signs of compressive optic neuropathy and low risk of neuro-ophthalmic impairment. Conversion to surgical management is indicated upon clinical deterioration or tumor growth. Based on the findings of this study a decision tree for the management of orbital schwannomas is suggested.

Fine-Needle Aspiration Biopsy as a Diagnostic Modality for Orbital Adnexal Lymphoma.

Purpose To evaluate fine-needle aspiration biopsy (FNAB) as a diagnostic tool for lymphoproliferative orbital lesions in light of recent improvements in cytomorphological and immunologic analyses. Method Retrospective case series including all orbital FNABs with a lymphoproliferative outcome at Karolinska University Hospital, Stockholm, Sweden during the period 2005-2015. Results Of the 38 patients included, 31 (82%) were conclusively diagnosed as having lymphoma according to the first FNAB. Disease in 20 patients (65%) could be sub-classified. The diagnosis in seven patients (18%) was either inconclusive, suggestive of lymphoma, or reactive lymphatic infiltrate. These seven patients were re-investigated, and the initial suspected diagnosis of malignant lymphoma was confirmed in four. Two of the remaining three patients were initially diagnosed as having non-lymphoproliferative disease, however, this was later changed to a lympho¬proliferative diagnosis following re-investigation, while the results of both reFNAB and incisional biopsy were inconclusive in the third. Conclusion In the majority of the 38 patients, a definitive diagnosis of lymphoma could be made based on FNAB alone, using cytomorphological and immunological workup, and sub-classification was possible in 20 patients (65%). Primary low-grade malignant orbital lymphomas are traditionally treated with low-dose radiotherapy regardless of subtype, and incisional biopsy was not needed to initiate treatment. Our findings suggest that FNAB is a valid first option for the diagnosis of suspected orbital lymphomas due to the minimal risk of complications compared to incisional biopsy, and the fact that it can be performed as an outpatient procedure with no anesthesia.