We describe a female patient with a localized form of syringolymphoid hyperplasia with alopecia and anhidrosis (SLHA). This woman is the eleventh patient with this disease so far reported in the literature. She suffered from a slowly but continuously progressing single lesion on her right ankle. It took 7 years until the diagnosis of SLHA could be established. Many divergent diagnoses were assumed and different treatments were performed during this time. The final diagnosis was established by histopathology revealing syringotropic T-cell infiltrates. Clinical features were scattered brownish papules, which formed a sharply demarcated erythematous patch lacking hairs and sweat production. The progressive course of the disease and the unresponsiveness to treatments support the current view that SLHA is a syringotropic variant of mucinosis follicularis and therefore should be viewed as a facultative precursor lesion of mycosis fungoides. In our patient, during a 7-year follow-up, no T-cell lymphoma occurred. This case emphasizes the difficulties of establishing the diagnosis of SLHA, which requires cooperation between the dermatologist and dermatopathologist. (J Am Acad Dermatol 2001;45:127-30.)