[Morphological studies on abnormal human spermatids and spermatozoa (author's transl)]

Malformed spermatids and spermatozoa in the testes, epididymes, and ejaculates of 29 apparently healthy men and in 171 patients suffering from different andrological diseases were investigated with the electron microscope. The following types of malformations are described: 1) Malformations of the acrosome in contact with the nucleus of the spermatid: Vesicular inclusions in the acrosome vesicle, asymmetric thickenings of the acrosome cap, enfolding of the acrosomal lamina into the spermatid's nucleus, partial separation of the acrosome from the nucleus, apical knob-like thickenings of the acrosome. 2) Malformations of the acrosome independent from the spermatid's nucleus: the acrosomal material is contained in small vesicles, large vacuoles, in ring-like structures, in globular or shell-like laminar structures. The nucleus of such spermatids lacks an acrosome. 3) Malformations of the nucleus: inclusions of vesicles or membranes, excessive packages of membranes, gigantic nuclear vacuoles, lack of condensation of the caryoplasm. 4) Multinucleate spermatids: two or more nuclei within the pericaryon of one spermatid are joined by an acrosome. 5) Duplicate acrosome anlagen. 6) Malformations of the tail: disorganization of the axonema, a lack or excessive numbers of tubules and fibres, doublets of the axial filaments, destruction of the neck region, a lack of the mitochondrial sheath, and enlargement of the fibrous sheath. Malformed germ cells were observed to occur in varying amounts both in apparently healthy men and in those who were apparently infertile. This indicates that germ cell malformations are no absolute indicator of male infertility. However, certain distinct types of malformations (such as round-headed spermatozoa) are definitely associated with infertility, but only if all spermatozoa in the ejaculate of a patient have the same defect.