[Stiff-tail or midpiece syndrome].

A rare spermatological malformation was seen in a 40 year old Turkish man with unexplained infertility since 17 years. Most of the spermatozoa were completely stiff, some of them developed a decreased motility confined only to the end of the flagellum. Electron microscopy studies revealed strongly elongated and partly disorganized mitochondrial sheaths; cytoplasma droplets were found frequently.