Granulosa cell pyknosis in the dominant follicle of monkeys

One of the primary morphologic criteria used as the first sign of degeneration of an antral follicle is the presence of a pyknotic nucleus in granulosa cells lining the lumen. This study was undertaken to determine whether granulosa cells with a pyknotic nucleus are also present in the putative dominant follicle. Dominance was verified by elevations of estradiol either following luteectomy or during the later stages of the follicular phase of the menstrual cycle. Some pyknosis is normal even in the viable dominant follicle at cycle day 8 or 12. Therefore, when evaluating the morphologic status of a follicle, one should examine several areas to assure proper evaluation.