Cutaneous infiltration in T-cell prolymphocytic leukaemia.

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive leukaemia accounting for over 30% of all mature T-cell malignancies. We describe the clinical manifestations and histology of cutaneous involvement in a series of 92 patients with T-PLL. Of the 92 patients, 26 (28%) had cutaneous involvement, and in 23 this was present at the time of the diagnosis of the leukaemia. Skin manifestations included a diffuse infiltrated erythema, infiltration localized to the face and ears, nodules and erythroderma. Histology showed a perivascular and periappendageal dermal infiltrate of lymphoid cells with the morphology of prolymphocytes. An early skin biopsy in these patients should help to reveal the underlying diagnosis