Cytogenetic analysis of a poorly differentiated adenocarcinoma of the prostate revealed the complex karyotype: 76-86,X, -Y, +X, +X, +del(X)(q24), +t(1;10) (p22;q24), -2, +der(2) t(1;2;?)(p32;q24p13;?), +der(2)t(1;2;?) (p32;dq24p13;?), +3, +3, +4, +5, +5, +6, +7, +del(7) (q22), -8, +der(8)t(8;?)(q24;?), + der(8)t(8;?)(q24;?), +9, +10, +10, +der(10)t (1;10)(q24;q22), +del (10)(q23), +11, +11, +12, +der(12)t(4;12)(q11;p11), +der(12)t(4;12) (q11;p11), +14, +der (15)t(1;15)(q21;p11), +t(16;?) (q21;?), +17, +18, +19, +19, +20, +20, +21, +22, +2-5 mar. The karyotype contains deletions of both 7q and 10q, abnormalities that also have been described previously in prostatic adenocarcinomas, and which hence may represent primary chromosomal rearrangements in this type of cancer.