Ovotestes

An ovotestis is a gonad that contains both ovarian and testicular tissue. This can occur as part of normal biology in some hermaphroditic species, and in humans it refers to a rare form of intersex variation or ovotesticular disorder of sex development (DSD).

In non-human animals, ovotestes are found in a variety of species with hermaphroditic or flexible-sex reproductive strategies, including certain mollusks and fish, where the organ can produce both oocytes and sperm and function as a single or paired gonad.

In humans, ovotestis describes a gonad that contains both ovarian and testicular components, which may be present in one gonad (unilateral) or in both (bilateral). Histology typically shows ovarian tissue adjacent to testicular tissue, sometimes in discrete areas within the same gonad. Individuals may have a range of external genitalia and secondary sexual characteristics, reflecting diverse patterns of gonadal function and hormonal exposure. The condition is a subset of disorders of sex development (DSD); karyotypes can be 46,XX, 46,XY, or mosaic (for example 46,XX/46,XY). Causes are heterogeneous and may involve atypical gonadal differentiation, presence of Y chromosome material with associated germ cell tumor risk, or other genetic and developmental factors.

Diagnosis typically involves clinical assessment, karyotyping, hormonal evaluation, imaging, and, when indicated, histopathological examination of gonadal tissue. Management is multidisciplinary and individualized, balancing gender identity considerations, potential fertility, and cancer risk—particularly the risk of germ cell tumors in gonads containing Y material.