Novel insight for midline cyst formation in prostate: The involvement of decreased prenatal testosterone suggested by second-to-fourth digit ratio study.
OBJECTIVE
To clarify the relationship between midline cyst formation and second to fourth finger length ratio.


METHODS
The present study included 95 benign prostatic hyperplasia patients and 61 healthy male college students. All midline cysts were identified by transrectal ultrasonography. In the benign prostatic hyperplasia group, 45 midline cyst (+) men (M(age) = 67.2 years) and age-matched 50 midline cyst (-) men (M(age) = 67.1 years) were included. In the university student group, 12 midline cyst (+) men (M(age) = 21.7 years) and age-matched 49 midline cyst (-) men (Mage = 21.1 years) were included. We took photocopies of the participants' bilateral hands, and measured the second and fourth finger length was measured by one examiner in a blind manner.


RESULTS
Second to fourth finger length ratios in the benign prostatic hyperplasia group (right/left mean ± SD) were higher bilaterally in midline cyst (+) (0.95 ± 0.03/0.95 ± 0.03) than those in midline cyst (-) (0.92 ± 0.03/0.92 ± 0.03; P < 0.0001/P = 0.0010). Second to fourth finger length ratios in students were higher only in the right hand in midline cyst (+) (0.96 ± 0.03/0.94 ± 0.03) than those in midline cyst (-) (0.93 ± 0.03/0.94 ± 0.03; P = 0.0018/P = 0.9968). The second to fourth finger length ratio of midline cyst (+) men was significantly higher than that in midline cyst (-) men.


CONCLUSIONS
The second to fourth finger length ratio is higher in subjects with midline cyst of the prostate. It can be speculated that the prostatic utricle dilates in cases less exposed to male hormones during fetal development.
Furuya Hospital, Kitami, Hokkaido, Japan.
Seiji
S
Furuya
Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
Shin-Ichi
S
Hisasue
Department of Urology, School of Medicine, Shinshu University, Matsumoto, Nagano, Japan.
Haruaki
H
Kato
Department of Urology, Sapporo Jieitai Hospital, Sapporo, Hokkaido, Japan.
Shogo
S
Shimamura
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003560:Cysts / Q000000981:diagnostic imaging*; D005385:Fingers / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging*; D013739:Testosterone / Q000097:blood*; D014463:Ultrasonography; D055815:Young Adult
D013739:Testosterone
2D:4D; digit ratio; midline cyst; prostate; testosterone