We treated a 43-year-old woman who had multiple thyroid cysts and coexistent toxic nodules localized to the left lobe. After surgical excision of this lobe, the patient's right lobe proceeded to function normally, displaying no evidence of nodules, cysts, or hyperfunction. Since toxic multinodular goiter is usually a diffuse process involving the whole gland, this case is unique and underlines the wide variability in the manifestation of this disorder.
