A vase-like shape characterizes the epidermal-mononuclear cell collections seen in spongiotic dermatitis.

Collections of mononuclear cells are seen within the epidermis in both mycosis fungoides and spongiotic dermatitis. Criteria have been proposed to differentiate between such Pautrier microabscesses or collections, and thier spongiotic mimics. We noted that the collections often assume a vase-like shape when spongiosis is present, with the lips of the vase situated at the interface between granular and cornified layers. Vase-shaped collections were present in five of 49 consecutive biopsy specimens of spongiotic dermatitis, but in none of 50 specimens of mycosis fungoides. These collections can, however, be seen in mycosis fungoides when pronounced spongiosis is present and should be considered as a marker of the process, spongiosis, rather than being diagnostic of spongiotic dermatitis.