Disappearance of Plasma Melatonin after Removal of a Neoplastic Pineal Gland

ALTHOUGH tumors of the pineal gland are not the most common brain tumors, their treatment is among the most controversial. The controversy relates in part to the fact that current neurodiagnostic techniques can detect very small lesions but cannot identify the type of tumor cell.¹ Consequently, we^{2 3 4} and others⁵ have called into question the standard treatment for lesions of the pineal gland: radiotherapy without a tissue diagnosis.⁶ In Japan, where the highly radiosensitive germinoma is by far the most common pineal-gland tumor, this controversy may be less pertinent.⁷ However, in the United States up to 40 per cent of tumors.