Pineal region tumors: Clinical symptoms and syndromes

Abstract

The present paper investigates the clinical picture and the different clinical signs that reveal pineal region tumors or appear during the course of the follow-up. Biological malignancy and tumor extension determine the semiology and its setting up mode. Typical endocrine signs, dominated by abnormal puberty development, are frequently a part of the clinical scene. Bifocal or ectopic localization in the hypothalamic-pituitary region is accompanied by other endocrine signs such as ante- or post-pituitary insufficiencies which occur several months or even years after the first neurological signs appear. Due to a mass syndrome and obstructive hydrocephalus, intracranial hypertension signs are frequent but unspecific. A careful ophthalmologic examination is essential to search upward gaze paralysis and other signs of the Parinaud's tetrad or pentad. Midbrain dysfunction, including extrinsic aqueduct stenosis, are also prevalent. Except for abnormal pubertal signs, hyper-melatoninemia (secretory tumors) or a-hypo-melatoninemia (tumors destructing pineal) generally remains dormant. Some patients present sleep problems such as narcolepsy or sleepiness during the daytime as well as behavioral problems. This suggests a hypothalamic extension rather than a true consequence of melatonin secretion anomalies. Similarly, some patients may present signs of a “pinealectomized” syndrome, including (cluster) headaches, tiredness, eventually responsive to melatonin.

Résumé

Le papier décrit le tableau clinique et les différents signes révélant chez l’enfant ou l’adulte les tumeurs de la région pinéale ou apparaissant au cours de leur évolution. Le degré de malignité et l’extension tumorale déterminent la sémiologie et son mode d’installation. De façon typique, les signes endocrinologiques, avec en terme de fréquence un trouble du développement pubertaire chez l’enfant, inaugurent la scène clinique. Une localisation ectopique ou bifocale dans la région hypophyso-hypothalamique est accompagnée par d’autres signes d’insuffisance ante- ou post-hypophysaire. Les premiers signes neurologiques apparaissent plusieurs mois ou même des années après. Une sémiologie d’hypertension intracrânienne est fréquente, mais non spécifique, du fait de la masse tumorale et de la compression habituelle de l’aqueduc de Sylvius. L’examen ophtalmologique détaillé est essentiel à la recherche d’une paralysie conjuguée du regard vers le haut ainsi que les autres symptômes de la tétrade ou pentade de Parinaud. En effet, malgré l’appartenance de la pinéale au diencéphale, sa proximité anatomique avec les pédoncules fait que la sémiologie d’origine mésencéphalique est prévalente. Si on excepte les signes endocrinologiques, les signes d’hypermélatoninémie (tumeurs sécrétantes) ou d’a-hypo-mélatoninémie (tumeurs détruisant la pinéale) est généralement silencieuse. Quelques patients présentent des troubles du sommeil de type syndrome narcoleptique secondaire ou somnolence diurne, et des troubles du comportement. Cela traduit plus une extension tumorale hypothalamique qu’une conséquence vraie d’une anomalie de sécrétion de mélatonine. Dans le même ordre d’idée, quelques patients présentent des signes du syndrome des « pinéalomectomisés » qui associe céphalées pouvant évoquer une algie vasculaire de la face, fatigue, dysthymie, troubles de l’éveil, éventuellement sensibles à la mélatonine.

Introduction

The pineal gland is so tiny and so deeply buried between the two cerebral hemispheres that it could be easily overlooked during a rapid glimpse of the brain. Traditionally, its central position inside the brain was considered as the “seat of the soul” (Descartes). The appendage of the brain is considered by some esoteric beliefs as the connection point between intellect or mind and body [1]. Pineal pathology constructs this paradox that the gland plays an important physiological role, but its surgical removal – at the same time of a mass lesion – has limited or no clinical effect. Pineal mass lesions are at an anatomically crucial site, at a crossroad between the brainstem and cerebrum, where they can produce various interesting clinical syndromes [except for cranial hypertensive symptoms as in any expansive processes] that hallmark either a posterior cerebral fossa, or a supra-tentorial pathology. Surgical approaches are multiple and still widely discussed [2]. Lesion histopathology and biological malignancy are extensive [3], disproportionate to its diminutive size, and decides on the clinical picture. Multiple tumor types, some recently, have been described. Until fairly recently, not much was known of the gland's physiology and significance. Since the end of the fifties, the advent of radioimmunoassay that detect pineal products and staining techniques that define the complex interconnections between the organ and its near and distant neighbors, and more recently molecular biology [4], have established the physiology and the clinical importance of the pineal. By analogy to phylogenetically lower species, confirms that the pineal gland is indeed a photoreceptor organ, synchronizing many of the hormonal and neurobehavioral activities as regards circadian variations in an environmental light. It also highlights its integration within the entire nervous system.