The rare familial occurrence of mycosis fungoides of exceptionally long duration in a brother and sister is reported. In the sister, the illness lasted for 39 years in the premycotic and infiltrative stages, and an acute myeloblastic leukemia developed three weeks before her death. The skin lesions of the brother lasted for 18 years and displayed the three classical stages of mycosis fungoides. Neither clinically nor at autopsy could a visceral involvement be detected. The slow development of the condition from subacute dermatitis to the tumoral stage is demonstrated in the illustrations of the skin biopsies.
Sandbank M, Katzenellenbogen I. Mycosis Fungoides ofProlonged Duration in Siblings. Arch Dermatol. 1968;98(6):620-627. doi:10.1001/archderm.1968.01610180064008