A Rare Case of Subconjunctival Nerve Sheath Myxoma Presenting as Orbital Fat Prolapse
Author: Sebastiaan van Meyel
Base Hospital / Institution: Rotterdam Eye Hospital
ePoster presentation
Abstract ID: 24-474
Purpose
Nerve sheath myxomas are extremely rare myxoid peripheral nerve sheath tumors with a predilection for the distal extremities, particularly common in the fingers and knees. Here, we report a 60-year-old male patient with a subconjunctival epibulbar nerve sheath myxoma, which was clinically diagnosed as an orbital fat prolapse. The lesion was successfully debulked without clinical recurrence over more than 3 years. To our knowledge, this is the first case with subconjunctival presentation and fourth orbital reported case.
Methods
A 60-year-old male presented at the outpatient clinic with a 10- to 15-year history of a painless superotemporal epibulbar swelling in the OS, which had drastically increased in size the past year. The patient had no symptoms and on initial examination, visual acuity was 1.20 and 1.00 in the OD and OS, respectively. The painless, subconjunctival mass was palpable in the superior temporal region of the OS, which had a soft cystic aspect and was yellow/pink in color.
Results
The patient was treated with subtotal debulking through a transconjunctival approach. Upon preliminary inspection, the color was not typical of a fat prolapse and looked more cystic than fat. There was no postoperative reduction in visual acuity or other complications or symptoms. Histopathology was most conclusive for an NSM. Microscopy showed a multinodular myxomatous spindle cell lesion with dispersed, somewhat fragmented coarse collagen fiber bundles and scattered mast cells. Additional immunohistochemical analysis showed that the lesional spindle cells uniformly stained positive for S100, SOX9, SOX10, and CD34. Altogether, conjunctival NSM was proposed as the final diagnosis.
Conclusion
The patient was followed up every 6 months as it is known that NSMs often recur. To date, 41 months after excision, no signs of recurrence have been detected. The presentation of (peri)orbital NSM lesion as a subconjunctival orbital mass is, to our knowledge, unreported. This case shows that a broader differential diagnosis should be considered for subconjunctival lesions clinically suggestive of fat prolapse.
Additional Authors
| First name | Last name | Base Hospital / Institution |
|---|---|---|
| Robert | Verdijk | Rotterdam Eye Hospital |
| Nele | Therssen | Rotterdam Eye Hospital |
| Dion | Paridaens | Rotterdam Eye Hospital |
