[Amyloidosis--a rare differential diagnosis of an orbital tumour].

BACKGROUND: Amyloidosis is a disorder caused by a misfoulding of proteins. The deposition of these proteins in tissues and organs can affect the normal function of those tissues and organs.
MATERIALS AND METHODS: Two patients are presented and an overview over the so far published cases with a localised orbital amyloidosis is given.
RESULTS: The first case is a 50-year-old woman with progressive ptosis since half a year, progressive proptosis since three months and deterioration of motility and deviation of the left globe. The second case is a 68-year-old man with progressive ptosis since four years and with affection of the subtarsal conjunctiva of the right eye. Macroscopically a yellow-brown, gelatinous, easily crumbled material was seen during operation.
CONCLUSION: the histological proof of amyloidosis can be made visually in intense unidirectional polarised light after congo red staining. This should be done in suspected cases every time. The orbita can also be involved in systemic forms of amyloidosis, so a systemic form should be excluded. The localised amyloidosis has no effect on the survival time in contrast to the systemic forms does have an effect. An untreated systemic form may be associuated with a prognosis of only 9 to 13 months. © Georg Thieme Verlag KG Stuttgart · New York.