[Orbital myopathy in metastatic malignant paraganglioma: a paraneoplastic syndrome?].

BACKGROUND: Several disease entities of the orbit are known which display an autoimmunological pathogenesis. Among these disease entities the thyroid-related immune orbitopathy and the idiopathic orbital inflammatory syndrome (orbital pseudotumor). The pathogenesis of these diseases is not well understood; however, an autoimmune inflammatory reaction histologically characterized by a chronic inflammatory cell infiltrate has been suggested. One care of orbital pseudotumor presumably of paraneoplastic origin occurring in a patient with a non-Hodgkin's lymphoma has been reported. We report a patient with a metastatic paraganglioma and a proptosis secondary to enlargement of all extraocular muscles.

CASE REPORT: A 52-year-old woman presented with a recent decline in visual clarity of her left eye and diplopia. Two years ago, the diagnosis of a hormonally inactive paraganglioma has been made. Ophthalmologic examination displayed a lagophthalmos caused by a right-sided facial paralysis secondary to a cerebral metastasis and a bilateral enlargement of all extraocular muscles. Curative therapy for the paraganglioma was not available. Palliative therapy as well as a high-dose corticosteroid therapy for the orbitopathy was refused by the patient. The patient died 18 months later.

DISCUSSION: Our patient developed orbital changes similar to thyroid-related immune orbitopathy; however, there was no dysfunction of the thyroid. We believe that the orbital changes were a paraneoplastic immune reaction caused by the metastatic paraganglioma. We recommend that in patients who do not conform to the prototypical profile of well-known orbital disease entities should undergo further testing to exclude a remote neoplasm.