Talk:Book - The Pineal Organ (1940) 1

THE PINEAL ORGAN

CHAPTER I

INTRODUCTION

The pineal organ has interested scientific investigators from the earliest times and much speculation has been expended in attempts to discover what its function might be. But it is only in very recent years that the medical profession has realized that it has a practical importance and that tumours may occur in this small piece of cerebral tissue. It was little more than fifty years ago that the late Sir Rickman Godlee performed the first operation for the removal of a cerebral tumour, yet in the comparatively short period of time which has elapsed since then great advances in both the diagnosis and treatment of such tumours have been made, and among the various types of cerebral tumour which have been distinguished and surgically treated are those which originate in or near the pineal body. The first real discussion on pineal tumours took place at the Royal Society of Medicine in London in 1909, when the subject was introduced by Hinds Howell. At this meeting Gordon Holmes stated that in his opinion surgical removal of pineal tumours arising in the pineal gland was feasible, and Sir Victor Horsley said that he would operate on the first case that came his way, by a supratentorial route. History, however, does not relate whether Horsley ever did operate upon a pineal tumour. Since the first discussion many cases of pineal tumour have been published, and in this short monograph we record nine cases.

The pineal organ after puberty frequently becomes calcified and its shadow can be seen on an X-ray film (Fig. 1). As the organ is a midline structure it is liable to be shifted from this central position if any pressure is brought to bear upon it from either side. Hence a cerebral tumour in the right hemisphere will shift it towards the left, and this " pineal shift " can easily be demonstrated in an antero-posterior skiagram. This in itself, apart from any pathological condition of the pineal body, may be a valuable localizing sign in the diagnosis of cerebral tumours. We have found the pineal gland to be calcified in 65 per cent, of patients over 16 years of age. This occurred in the examination of over 300 adult skulls, and there can be no doubt that with improved technique and better X-ray apparatus the percentage of calcified pineals which are visible and are recorded will gradually rise.

The pineal organ is thus of considerable importance in general medicine, and as the years go by and pineal lesions are more frequently recognized, this importance will become more marked.

As one branch of medicine advances it becomes repeatedly necessary to fall back on the fundamental sciences for help and guidance, and

Fig. i. — Calcification of Pineal Organ.

realizing that the investigation of these pineal tumours proved rather barren some years ago, the authors determined to investigate the whole question of the nature of the pineal organ from the lowest to the highest forms in the animal kingdom and see if this would shed any light on these interesting and little-known tumours of the pineal which so often are not diagnosed in the early stages when complete removal would be much easier than if left to grow large and involve neighbouring structures.