ESMO Asia Congress 2022

Abstract YO7

Case summary

Introduction:

The orbit is an unusual site for metastatic cancer. Orbital metastasis is believed to occur in approximately 2% to 3% of patients with systemic cancer.

Case Presentation:

A 58-year-old male with history of three month history of on and off orbital swelling presented with right hip pain. He had a history of high-risk prostate cancer July 2019 status post radical prostatectomy, leuprolide and salvage radiotherapy. He was put on androgen deprivation therapy(ADT) break from December 2021 until repeat PSA in April 2022 was 107. A repeat CT-CAP and bone scan on 4/21/2022 which showed diffuse bony metastasis including R iliac wing and calvarium. Patient was started on degarelix and sent to a medical oncologist. He was started on leuprolide and enzalutamide and received palliative radiotherapy for right hip pain. During his radiotherapy patient developed worsening right hip pain for which he had to be admitted.On day 3 of admission patient developed significant chemosis, significant extraocular muscle restriction particularly in abduction. CT Scan of the maxillofacial region showed significant right periorbital swelling with potential post septal involvement noted on the right. Multiple calvarial lesions were also noted. Magnetic resonance imaging (MRI) head showed tumor infiltration of the skull base and frontal bones with intraorbital extraconal subperiosteal tumor and bifrontal epidural tumor extension. Steroids were started. Periorbital swelling resolved on day 6. Biopsy was deferred.

Discussion

The median age for orbital metastasis reported is at 70 years however our patient is younger. In general, patients present with ocular symptoms such as decreased vision, diplopia, proptosis and periorbital edema. Metastatic cancer most commonly develops in the uveal tract. Metastasis to the retina, optic disc, and vitreous are relatively uncommon. Metastasis to the bony orbit although rare, has been reported in the past. Extraconal space is the area outside musculofascial cone in the eye. Although both bony and soft tissue metastasis involving the uveal tract have been reported in the past, extraconal orbital soft tissue metastasis secondary to PC is only reported once and is extremely rare.Treatment options include ADT and cranial irradiation.