SLC2A1 and isolated hemihyperplasia: Differential diagnoses include LM, angiokeratoma, venous malformation, capillary-LM, and IH.5, 1, 2, 3, 4 Size, focal GLUT1 immunopositivity, pattern of progressive growth and hyperkeratosis, and proliferation of veins in the dermis and subcutis are key diagnostic features.1, 2, 3, 4 Numerous treatments have been reported, including topical corticosteroids, radiotherapy, pulsed dye or long-pulsed neodymium-doped yttrium aluminum garnet laser therapy with excision, and oral or topical sirolimus.2