[Segmental anhidrosis associated with Adie's pupil: an incomplete case of Ross syndrome].

We present the case of a 43-year-old woman who presented with a localized area of anhidrosis on the upper left trunk and ipsilateral upper limb. It was associated with Adie's tonic pupil and an area of compensatory hyperhidrosis on the contralateral side. After 9 years of follow up, the alterations have remained stable. These alterations of the autonomous nervous system correspond to an incompletely expressed Ross syndrome.