Chromosome changes in mycosis fungoides in an XYY male.

A 32-year-old white male was diagnosed as having mycosis fungoides in 1976; bone marrow biopsy and aspiration in August 1984 revealed infiltration with neoplastic cells. Cytogenetic analysis of the cells from the bone marrow specimen showed that 48 of 50 metaphases contained an extra Y chromosome (i.e., 47,XYY). The remaining two cells were hypotetraploid and hyperpentaploid, respectively, with a common marker derived from chromosome #2. The metaphases obtained by PHA stimulation of peripheral blood cells showed a 47,XYY pattern. An interleukin 2 (IL-2) dependent T-cell line was established from the patient's blood mononuclear cells; all metaphases of this line had an extra Y chromosome. Thus, this case is one of a mycosis fungoides developing in an XYY male.