A case of pagetoid reticulosis treated with topical photodynamic therapy

A 70-year-old male presented with reddish brown, keratotic plaque on his left leg which had grown slowly for ten years. The histopathological examination revealed acanthosis and bands of lymphocytes with significant epidermotropism. The intraepidermal lymphocytes showed large, pleomorphic and hyperchromatic nuclei with distinct nucleoli and perinuclear halos, positive for CD3, CD4 and CD30, negative for CD8, CD20 and high in Ki67 index. Accordingly, the diagnosis of Pagetoid reticulosis was made. The patient was then treated with topical photodynamic therapy once a week sequential to partial in-situ resection and preliminary skin dermabrasion and finally achieved complete remission without obvious scars or recurrence after four sessions.