Thyroid-associated ophthalmopathy is a common manifestation of Graves' disease. Its pathophysiology is not well understood but an antigen shared between the thyroid and orbit is thought to play a role. Using immunohistochemistry, we have demonstrated the presence of the autoantigenic target of Graves' disease, the thyroid-stimulating hormone receptor, in normal human extraocular muscle. These results support previous findings of the full length and splice variant thyroid-stimulating hormone receptor cDNA in extraocular muscle. The observation of the autoimmune target--the thyroid-stimulating hormone receptor protein--being shared between the thyroid and extraocular muscle lends greater support to the notion that an extraocular muscle thyroid-stimulating hormone receptor is also a likely target autoantigen in thyroid-associated ophthalmopathy.

Improved understanding of the pathogenic mechanisms of GO should hopefully lead to new diagnostic and therapeutic approaches to this problematic condition.

Primary nasolacrimal duct malignacy is rare. Only a few tumours have been reported originating from this location including lymphoma, 1 Kaposi's sarcoma, 2 adenocarcinoma, 3 angiofibroma, 4 and squamous cell carcinoma. 5 Mucosal melanoma represents 1-2% of all melanomas, 6 with 25-50% in the head and neck-that is, upper respiratory tract, oral cavity, and pharynx. Other sites include urinary, female genital, and ano-rectal tracts. These tumours are uncommon, present in the fifth to eighth decades, have slight male preponderance and are more common in darker skinned individuals. Cutaneous melanoma presents two decades earlier and is more common in white people and is associated with sun exposure.