rarely used term for a disorder in which the seminiferous tubules exhibit an abnormal cytoarchitecture and extensive hyalinization; the testes are small, and few spermatozoa are formed; the body habitus may be eunuchoid, and gynecomastia may be present; urinary gonadotropin output is usually high, and the incidence of mental deficiency and illness increased; sex chromatin may be male or female, and androgen secretion ranges from subnormal to normal. It is a constant feature of (and the term may be used synonymously with) Klinefelter syndrome. SYN: germinal aplasia.