Failure of detection of mucin in the clear halos around the epidermotropic lymphocytes in mycosis fungoides

Epidermotropic lymphocytes in mycosis fungoides typically reside in clear lacunae. The material forming this space is unknown. Thirty specimens from 30 patients with mycosis fungoides were stained with alcian blue, modified Mowry's colloidal iron and mucicarmine to determine if some form of mucin could be identified. Using these stains, no form of mucin was noted in the lacunae surrounding the epidermotropic lymphocytes of mycosis fungoides. The cause of the clear spaces around epidermotropic lymphocytes in mycosis fungoides remains unexplained, but is unlikely to represent mucin deposition.