Mixed gonadal dysgenesis and cell line differentiation. Case presentation and literature review.

A male patient with mixed gonadal dysgenesis, involving a streak gonad on the right and a histologically normal testis in the left, was found to have a 45,X/46,X,dic(Yp) chromosome constitution on peripheral blood cultures. Fibroblasts grown from both gonads showed the "normal" testicular tissue to have e 45,X/46,X,dic(Yp), whereas the cells from the streak gonad were all 45,X. The structure of the dic(Yp) chromosome was confirmed using non-isotopic in situ hybridization with Y centromere and Yp specific probes. On hormonal stimulation, testosterone levels rose by 50%. The "normal" testis was left in situ, but close follow up will be required in view of the malignant potential.