[A case of sarcoid myopaty with external ocular muscle involvement--diagnosis and follow-up study with 99mTc pyrophosphate scintigraphy].

A 62-year-old woman was admitted to our hospital because of diplopia and muscular weakness. She had been diagnosed as having sarcoidosis histologically by skin biopsy 5 years before. Although neither CT nor MRI could detect the granulomas, 99mTc-pyrophosphate scintigraphy successfully detected the involvement of sarcoidosis not only in the skeletal muscles but also in the external ocular muscles. After treatment with prednisolone, the symptoms markedly subsided and increased uptake of radionucleotide disappeared. Although 67Ga scintigraphy is also known to be useful in investigating the sites affected by sarcoidosis throughout the body, it was not effective in detecting the involvement of external ocular muscle due to the physiological uptake of 67Ga to the lacrimal grands. While the granulomas are frequently observed histologically in skeletal muscles, usually they are not associated with muscle symptoms. In our study 99mTc-pyrophosphate scintigraphy has proven to be useful in investigating the nodular lesions in skeletal muscles of sarcoidosis than 67Ga scintigraphy.