Orbital Cellulitis or Metastasis? Prostate Cancer Masquerading in the Orbit
Author: Elizabeth Leong
Base Hospital / Institution: National University Hospital Singapore
ePoster presentation
Abstract ID: 25-304
Purpose
To report a rare first‐presentation of prostate adenocarcinoma masquerading as orbital cellulitis and to highlight key distinctions between infectious orbital inflammation and metastatic disease.
Methods
We analysed a case of an 86-year-old male who presented with acute left periorbital swelling, pain, chemosis, and reduced vision. Clinical, laboratory, and imaging data were reviewed. He was treated for presumed left orbital cellulitis, but imaging revealed an orbital mass with bone destruction. He underwent anterior orbitotomy with biopsy and histopathology with immunohistochemistry confirmed the diagnosis. A focused literature review on orbital metastases from prostate cancer and on differentiating orbital cellulitis from orbital malignancy was also conducted.
Results
Radiological imaging showed a rim-enhancing preseptal fluid collection and an extra-conal mass with aggressive bony erosion. Persistent inflammation despite antibiotics and atypical imaging prompted biopsy. Histology revealed necrotic tumor strongly positive for NKX 3.1, confirming prostate origin despite negative PSA staining. Subsequent systemic workup revealed metastatic prostate adenocarcinoma with widespread bony involvement. The patient commenced androgen deprivation therapy; orbital inflammation resolved, and post-cataract surgery his vision recovered to 6/9 in the affected eye.
Conclusion
Although prostate cancer commonly metastasizes to bone, orbital involvement is exceedingly rare (<1% of orbital tumors, ~12% of orbital metastases). Our case illustrates how orbital metastases can mimic features of orbital cellulitis. Key distinctions include poor antibiotic response, lack of systemic infection signs, aggressive bony erosion and the presence of a solid mass rather than simple rim-enhancing fluid on imaging. Early imaging and biopsy are critical to avoid treatment delays and to initiate appropriate oncologic therapy. NKX 3.1 is a valuable immunohistochemical marker to identify prostate origin, particularly when PSA is negative.
Additional Authors
| First name | Last name | Base Hospital / Institution |
|---|---|---|
| Maryanne | Romero | National University Hospital Singapore |
| Gangadhara | Sundar | National University Hospital Singapore |
