Metastatic Tumors in Adults
Although virtually any cancer of the internal organs, hematopoietic system, or skin can metastasize to the orbit, most orbital metastases derive from lung, breast, and prostate tumors. The presence of pain, proptosis, inflammation, bone destruction, and early ophthalmoplegia suggests the possibility of metastatic carcinoma.
Some 75% of patients have a history of a known primary tumor, but orbital metastasis is the presenting sign of cancer in 25% of patients. The extraocular muscles are frequently involved because of their abundant blood supply. The second most common site is the bone marrow space of the sphenoid bone because of the relatively high volume of low-flow blood in this area (Fig 5-26). Lytic destruction of this part of the lateral orbital wall is highly suggestive of metastatic disease. Elevation of serum carcinoembryonic antigen levels also may suggest a metastatic process. Fine-needle aspiration biopsy can be performed in the office and may obviate the need for orbitotomy and open biopsy.
Figure 5-26 Metastatic prostate cancer. A, Left proptosis and orbital congestion in a patient with prostate carcinoma. B, CT scan shows a left posterior orbital mass with adjacent bony destruction, confirmed by biopsy to be metastatic prostate cancer.
(Courtesy of Roberta E. Gausas, MD.)
The most common primary source of orbital metastases in women is breast cancer. Metastases may occur many years after the breast lesion has been removed; thus, the history should always include inquiries about previous cancer surgery. Breast metastasis to the orbit can elicit a fibrous response that causes enophthalmos and, possibly, restriction of ocular motility (Fig 5-27).
Some patients with breast cancer respond favorably to hormone therapy. This response usually correlates with the presence of estrogen and other hormone receptors in the tumor tissue. Estrogen receptor assay results from orbital metastases may differ from those of the primary lesion; thus, orbital tissue studies should include this assay. Hormone therapy is most likely to help patients whose tumors are receptor positive.
The most frequent origin of orbital metastasis in men is bronchogenic carcinoma. The primary lesion may be quite small, and CT of suspicious lung lesions may be performed in patients suspected of having orbital metastases.
Figure 5-27 Metastatic breast carcinoma. A, Left enophthalmos (arrows) secondary to breast carcinoma metastasis to the orbit. Coronal (B) and axial (C) MRI images show medial infiltration of the orbit (arrows).
(Courtesy of Hakan Demirci, MD.)
Metastatic prostate carcinoma can produce a clinical picture resembling that of acute nonspecific orbital inflammation. Typically, an osteoblastic bone lesion is identified on imaging.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.