Pineal region tumors: pathophysiological mechanisms of presenting symptoms

Pineal region tumors (PRTs) affect all ages, with a remarkable proportion of cases occurring in children. They are mainly classified into three categories, namely germ cell tumors (GCTs), pineal parenchymal tumors (PPTs), and other tumors such as gliomas and tumors of the surrounding structures. The purpose of this article is to review the current literature regarding pathophysiological mechanisms of the presenting clinical features of patients with PRT. The usual presentation of PRTs is the symptoms of obstructive hydrocephalus and intracranial hypertension, such as headache and vomiting. However, there is a remarkable spectrum of clinical findings that can be caused by such lesions. These include ophthalmologic and endocrinologic disturbances, motor and sensory abnormalities, and cognitive and psychiatric symptoms. The unique anatomic location of the pineal gland, which is close to many vital brain structures, is crucial for the explanation of most of those findings. In rare cases, manifestations of intracranial bleeding may be the presenting feature of a PRT. Tumor histology and patient's age can affect the clinical presentation. Hydrocephalus is the most common clinical syndrome of a PRT because of the location of the pineal gland. Presenting symptoms also include ophthalmologic, endocrinologic, motor, sensory, cognitive, and psychiatric symptoms. Clinicians should be aware of the initial symptoms of PRTs, including the misleading ones, in order to avoid delay in the diagnosis and management of these life-threatening lesions.