Acquired inflammatory superior oblique tendon sheath syndrome. A clinicopathologic study.

To our knowledge, this is the first reported clinicopathologic study of a patient with acquired inflammatory Brown's syndrome. The superior oblique tendon, trochlea, and anterior superior oblique muscle were surgically removed en bloc and studied by light microscopy. Surprisingly, the entire specimen was normal, without signs of inflammation or intrasheath scarring. The only abnormal finding was found during surgery, which consisted of perisheath adhesions anterior to the trochlea. These findings indicate that the cause of acquired inflammatory Brown's syndrome may, in many cases, be from scarring around the tendon sheath rather than an intrasheath pathologic condition, as proposed by recent literature.