LAUSR

A 48-year-old man presented with multiple pruritic dark red papules for 9 months. The lesions started on his hands and subsequently spread to the trunk and limbs within the last 2 months. He also had cyclical low fever with fatigue for a month. The dermatological examination revealed generalized brown papules and plaques distributed on his face, limbs, hands, waist, and feet (Fig. 1a–f). He denied suspicious medication history and family history of malignancy. Laboratory studies also revealed that his peripheral white blood count was 204.3 9 10/L (with 84.6% of lymphocytes) with normal hemoglobin and platelets. Peripheral blood smear revealed an increased number of mediumto large-sized lymphocytes with irregular nuclei. A skin biopsy showed normal epidermis (Fig. 2a). A granulomatous infiltrate composed of histiocytes, lymphocytes, and multinucleated giant cells into degenerated collagen was found in the upper dermis (Fig. 2b,c). Because of his leukocytosis, he was suggested to see a hematologist for further examination. The flow cytometry of peripheral blood revealed lymphocytes positive for CD2, CD3, CD4, CD5, CD7, CD28, and CD52. Electron microscopy showed atypical lymphoid cells with irregular-shaped nuclei and distinct nucleoli. Bone marrow aspirate showed many similar lymphocytes (62.5% of marrow cells), which was phenotypically identical to those in the peripheral blood. From those results, the diagnosis of T-cell prolymphocytic leukemia (T-PLL) was established. (c)