History of Management of Pineal Region Tumors in Children

Understanding of Disease

• 130-210 AD –pineal gland described by Galen: The pineal gland (Greek Konos, Latin pinus pinea) was first described by the Greek physician Galen of Pergamon (ca. 130-210 AD) (55).  On the basis of his observation in cadaveric studies, he likened the small, tan structure to the appearance of a pine nut.   Given its deep-seated intracranial location and proximity to vital neurovascular structures, Galen theorized that the pineal gland functioned to protect the contents of cerebral blood by controlling the flow of psychic pneuma, a vaporous substance contained by the cerebral ventricular system that constituted the material of consciousness, or “instrument of the soul.” 
• Modern times –neurosecretory organ: In modern times, the pineal gland was originally believed to be a vestigial remnant due to its neuroepithelial composition (16, 54).  It was not until anatomists traced fiber pathways from the optic apparatus to the pineal gland that the concept of a specialized neurosecretory organ with biological response to photic stimulation took shape.  With the discovery of the hormone melatonin in 1958 and improved histological techniques, scientists were able to characterize the biology of primary parenchymal cells and connected the function of the gland with hormone release in response to light and sleep-wake cycles (16,55).

Technological Development

• Neuroimaging:  The development first of CT scanning and then MRI has allowed for the diagnosis of pineal region lesions without invasive testing.
• Tumor markers: The development of laboratory assays for serum and CSF hormones that “mark” the presence of a pineal tumor has greatly advanced our ability to diagnose many pineal tumors without a tissue biopsy.  In some cases this information allows for treatment without an invasive procedure.
• Surgical technology:  Advances in image guidance or neuronavigation, magnified vision, and surgical instrumentation have allowed for safe access to the pineal region for tissue sampling and tumor resection.  Surgery has, consequently, become an important tool in the treatment of these tumors.
• Hydrocephalus management: Improved tools and techniques for diagnosis and management of obstructive hydrocephalus, including improved shunting devices, and the use of neuroendoscopy, have improved outcomes for patients with pineal region tumors.

Surgical Technique

Development of surgical approaches

• 1921 – Dandy’s interhemispheric transcallosal approach: In 1921, Dandy described the parietal interhemispheric, transcallosal approach to the pineal region (17).  Variations of this procedure are used today for certain types of tumors.
• 1937 – Horrax’s occipital transtentorial approach: In 1937 Horrax, and later Poppen in 1966, described an occipital transtentorial approach through a supratentorial craniotomy (38, 69). This procedure has evolved to become one of the most commonly used approaches to the pineal region.
• 1962– Krause’s infratentorial supracerebellar approach: An infratentorial supracerebellar approach was first described by Krause in 1962 and was later popularized by Stein during the 1970s (51, 84).  This approach is still widely used today.