Localized orbital amyloidosis - A varied presentation.

Localized orbital amyloidosis is rare, usually slowly progressive and benign disorder. The most common signs and symptoms include visible periocular mass, ptosis, proptosis, globe displacement, ocular motility disturbances, recurrent periocular subcutaneous hemorrhages, and dry eyes. Herein, we report a case of localized recurrent orbital amyloidosis with strabismus, restricted eye movement, ptosis, and orbital mass as the presentation in a 60-year-old female and managed with debulking and strabismus surgery, resulting in a good cosmetic and functional outcome. Copyright:

Introduction

Amyloidosis is a rare condition involving extracellular deposition of amorphous proteinaceous material that can involve multiple organs (systemic form) or be limited to only the involved organ without systemic circulating monoclonal proteins (local form).[1] Ocular involvement in amyloidosis is most commonly seen in the eyelid, followed by the orbit, conjunctiva, and lacrimal gland.[2] Localized orbital amyloidosis can have a recurrent and varied presentation. Here, we present a rare case of recurrent localized orbital amyloidosis managed with surgical debulking and strabismus surgery.

Case Report

A 60-year-old female presented with left eye downward displacement, gradually progressive drooping of left eyelid, and binocular horizontal, vertical, and torsional diplopia on clearing visual axis for the past 2 years. Levator palpebrae superioris (LPS) repair was done 20 years ago for progressive left eye ptosis. She was diagnosed as a biopsy proved localized orbital amyloidosis. She was lost to follow-up and presented to us several years later. No similar family history and no other significant history of precedent or current systemic illness were present. On ophthalmic examination, her corrected visual acuity was 6/9, N6 in both eyes. She had bumpy swelling involving the left upper lid producing severe ptosis and 3 mm of axial proptosis [Figure 1a]. She had large left hypotropia of around 40 prism diopters (PDs) in primary position for distance with “–”3 elevation limitation in the left eye [Figure 1b]. The rest of the ocular examination including intraocular pressure and fundus examination was unremarkable. Forced duction of the left eye was restricted in elevation. Axial and coronal sections on magnetic resonance imaging (MRI) revealed ill-defined soft tissue seen beneath the left tarsal plate and the superior periocular region around the insertion of the enlarged left superior rectus insertion and superior extraconal fat [Figure 2a]. Systemic workup for amyloidosis which included normal blood count and film examination, biochemical profile, erythrocyte sedimentation rate, liver function tests, coagulation parameters, 24-h urine protein electrophoresis, creatinine and albumin, glomerular filtration rate, ultrasound abdomen, bone marrow trephine biopsy, and aspiration cytology was reported as normal. The patient underwent left eye LPS debulking along with the inferior rectus recession. Biopsy sent for histopathology analysis obtained from the mass revealed an eosinophilic amorphous component. Congo red staining and birefringence proved the presence of amyloid deposits [Figure 2b-h], thus confirming the diagnosis as recurrent localized orbital amyloidosis. Postoperatively, the patient recovered well. On her final examination at 6 months, she had mild ptosis with residual hypotropia of around 14 PDs in primary gaze [Figure 3]. There was an improvement in her elevation, and she was able to fuse with no complaints of diplopia.

Figure 1

(a) External photograph showing bumpy swelling involving left upper lid producing severe ptosis (black arrow). (b) Nine gaze photograph showing large left hypotropia with 3 elevation limitation in the left eye

Figure 2

(a) Axial and coronal magnetic resonance imaging showing ill-defined soft tissue seen beneath the left tarsal plate and superior periocular region around insertion of enlarged superior rectus. (b) Intraoperative photograph of the excised mass sent for histopathology analysis. (c-e) HPE stain showing pale pink, amorphous extracellular, glassy, hyaline eosinophilic amyloid-like substance material mostly deposited in and around vessels (black arrows). (f and g) Congo red stain showing red color amyloid deposits (black arrows). (h) Congo red-stained tissue visualized under polarized light showing apple-green birefringence (black arrow)

Figure 3

Postoperative photograph showing improvement in ptosis and residual small left hypotropia

Discussion

Localized amyloidosis is rare, and orbital involvement is noted in only 4% of the cases with 1.3% of it involving deposition in extraocular muscles (EOMs).[2] Orbital involvement in amyloidosis can have varied and recurrent presentations as in our patient. Clinically, the most common presentation in orbital amyloidosis is a painless, palpable mass.[3] Other presentations include ptosis, proptosis, globe displacement, and diplopia secondary to restricted motility.[3] Our patient presented with orbital mass, ptosis, strabismus, proptosis, and elevation limitation. Ptosis preceded the detection of orbital mass by many years in our patient. Absence of pain differentiates orbital amyloidosis from idiopathic inflammatory orbital diseases.[4] Ptosis may occur due to LPS complex infiltration/stretching and mechanical due to the weight of amyloid itself. Ocular motility limitation occurs due to nodular infiltration of EOM and nearby adnexa.[5] Ptosis and ocular motility limitation can occur concurrently in localized amyloidosis or, as in our case, several years apart. EOM enlargement, soft-tissue infiltration, and calcification are characteristic findings seen on orbital imaging in orbital amyloidosis. On T2-weighted images in MRI, amyloid presents as an area of heterogeneous hypodensity, and on fat-saturated contrast-enhanced images, marked homogeneous enhancement is noted.[6] Diagnosis is a challenge due to its varied clinical presentation and requires a biopsy demonstrating apple-green birefringence on Congo red stain.[7] In the setting of localized orbital amyloidosis, a thorough review of systems and examination should be performed to rule out systemic involvement. Treatment modalities include observation, surgical debulking, and radiotherapy. Surgical debulking is the mainstay treatment modality for large tumors causing ocular motility disturbances, compressive optic neuropathy, and unsightly cosmesis.[8] Our patient underwent debulking of mass by excision along with squint surgery and had a favorable outcome. Although external beam radiation following excision has been noted to halt the progression and decrease recurrence rates in localized amyloidosis,[9] our patient refused this treatment modality as she was concerned about potential side effects of the treatment.

Orbital and periocular amyloidosis, although very rare, can present with a wide spectrum of clinical manifestations and can result in significant ocular morbidity. Although recurrence is common,[10] a long-term follow-up is very important as in our case and a complete surgical excision is not possible in many cases, and the goal of management would be to preserve function and prevent sight-threatening complication along with management of associated manifestation such as strabismus which in our case had quite a gratifying functional and cosmetic outcome.

Conclusion

This case emphasizes that recurrence can occur in amyloidosis and requires close monitoring.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal the identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.