Bullous Sézary syndrome

The clinical course of a patient with Sézary syndrome presenting under bullous form is described. The bullae were flaccid on a non-erythematous base. Indirect and direct immunofluorescence were both negative. In the peripheral blood WBC was high (54,000/mm3) and large cells with T lymphocyte properties and small cells with 'null' cell features were present. Blister fluid contained only large, E-rosette positive and alpha-naphthylacetate esterase-positive Sézary cells. A remarkable spontaneous cyclicity was observed: marked reduction in the number of large circulating Sézary cells each time bullae appeared. This suggests that only the large cells were capable of migrating to the skin and from the skin to peripheral blood.