Ph1-positive acute lymphoblastic leukemia associated with an isochromosome 17q

We report a patient with Ph1-positive acute lymphoblastic leukemia (ALL) having i(17q) in whom bony lesions were the initial clinical manifestation. The patient was a 53-year-old male who began to have pains in his left hip early in March 1985. Relevant findings on admission included: WBC 21,300/microliters; blast cells 73.5%; peripheral blood blast cells, peroxidase (-), PAS (-) and esterase (-); cytoimmunologic markers, Ia(+) cells 49.1%, CD10(+) cells 67.1%, CD20(+) cells 75.1%; positivity for TdT, and Ph1(+); and i(17q) upon chromosomal analysis. These findings led to a diagnosis of ALL with Ph1(+),i(17q). This case seems to represent an exceedingly rare instance of Ph1(+),i(17q) ALL in which the differential diagnosis between blast transformation of CML and Ph1(+) ALL was initially difficult to make.