Parietal foramina are not synonymous with giant parietal foramina

Introduction: Enlarged parietal foramina have historically been described as merely the normal parietal foramina (which usually transmit emissary veins connecting the occipital veins to the superior sagittal sinus) in which the diameter exceeds approximately 5.0 mm. Methods: We have observed well over 500 cadaveric wet and dry specimens for simultaneous bilateral enlarged and normal parietal foramina. Results: We have found two bony adult calvaria, which demonstrate both enlarged parietal 'foramina' and the normally appreciated parietal foramina. Conclusions: Although a rare occurrence, enlarged parietal foramina occur in conjunction with the normally sized and positioned parietal foramina. This dismisses earlier hypotheses that enlarged parietal foramina are merely parietal foramina that are increased in their diameter.