ENOPHTHALMOS DUE TO METASTATIC BREAST ADE NOCARCINOMA

Background Orbital metastatic disease usually leads to exophthalmos bu t rarely to enophthalmos. We report a case of a metastasis causing eno phthalmos. Patient A 68-year-old woman had mastectomy for breast cance r six years prior to presentation. She complained of double vision whe n looking sideways. The right eye showed a motility reduction in all d irections and a slight ptosis. She had 4 mm enophthalmos and the eyeli ds were sunk into the orbit. There were no signs of optic nerve damage . Magnetic resonance imaging showed a retobulbar mass sur rounding the optic nerve and infiltrating the muscles. The space of the orbital fa t was reduced. A biopsy confirmed the diagnosis of metastatic breast c arcinoma. Histologically, the connective tissue was infiltrated by lym phocytes. and the nuclei of the tumor cells where aligned in a linear ''indian file'' pattern. 30% of the tumor cells contained the estrogen -receptor protein, 40% the progesteron-receptor protein. The CA-1513 a nd CEA levels were elevated. The patient underwent orbital radiation w ith 50 Gy. During the following 2 months, the enophthalmos encreased t o 6 mm. Discussion We suggest the following hypothesis as the cause of enophthalmus in orbital metastases: The tumor growth goes along with fibrosis. Subsequent shrinkage of the connective tissue pulls the eye back into the orbit. The ensuing elevation of tissue pressure leads to atrophy of the retrobulbar fat. The increase of turner volume is too slow to compensate for the fat atrophy. Slowly progressive enophthalmo s with reduced motility is nearly pathognomonic of metastatic scirrhou s breast carcinoma. In rare cases, a diffusely infiltrating carcinoma of the gastrointestinal tract may cause a similar picture.