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 com- 

 paratively 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 dis- 

 tinguished 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 mid- 

 line 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 



I 1 



