Introduction: The pathophysiology of mycosis fungoides remains uncertain but HTLV I or a similar virus could be involved. We observed a couple who developed mycosis fungoides suggesting the infectious hypothesis might indeed be valid.
Case report: A 70-year-old man who had often travelled in foreign countries developed parapsoriasis en plaques, lymphomatoid papulosis and mycosis fungoides successively over a thirty year period. Several years after the first manifestation of mycosis fungoides, his wife also developed a single plaque of mycosis fungoides. The diagnosis was confirmed on pathology slides and immunohistochemistry tests as well as on the basis of T-receptor gene rearrangement in both patients. Search for HTLV I was negative using serology tests and PCR on circulating lymphocytes.
Comments: The epidemiological situation in our observation (several trips in foreign countries and the delayed development of mycosis fungoides in the wife) favours the hypothesis of an infectious mechanism. Search for HTLV I was unsuccessful with classical virology methods. Certain recent work suggests a virus similar but different from the HTLV I virus could be involved in the pathogenesis of mycosis fungoides.