UNREPORTED ANATOMICAL VARIATION OF SEPTUM PELLUCIDUM

During gross anatomy dissections of the brain, a developmental abnorma lity of the septum pellucidum was found in a 31-year-old male cadaver. Other parts of the central nervous system in this cadaver were normal in every aspect. Histological samples were taken from the neighboring areas of this abnormality, and they were examined under light microsc ope and scanning electron microscope. In this abnormality of the septu m pellucidum, the two laminae of the septum pellucidum were fused toge ther and there was a hole located 1 cm anterior to its apex. The maxim um diameter of the hole was 0.5 cm in the sagittal plane and 0.6 cm in the vertical plane. In the light microscopic and scanning electron mi croscopic examinations, the free margin of this foramen was regular, a nd the surrounding tissue was intact and histologically unique to the septum pellucidum. Ependymal cells were present at the free margin of the foramen. Cavum vergae, cavum septum pellucidum and agenesis of the septum pellucidum are described in the literature. These three abnorm alities are seen in cadavers usually with histories of schizophrenia a nd other psychiatric or neurologic disorders. In a retrospective study , the cadaver with this abnormality had a history of schizophrenia and no history or signs of any kind of brain or head operation. As far as we could ascertain, the abnormality described here has not been repor ted previously. (C) 1997 Wiley-Liss, Inc.