Cobblestoned ankles in Graves disease: koebnerized elephantiasic pretibial myxoedema

A 61-year-old man with Graves disease presented with bilateral perimalleolar cobblestoned plaques, elephantiasic pretibial myxoedema, with a linear koebnerized tract. Biopsy confirmed thyroid dermopathy (compact orthokeratosis, acanthosis, abundant interstitial dermal mucin on Alcian blue–PAS). This vignette spotlights the dermatology–internal medicine interface: a distinctive cutaneous sign of thyroid autoimmunity with atypical ankle/foot involvement and trauma/friction as a cofactor.