Presentation

The pineal gland produces the hormone melatonin

Melatonin

Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...

 which plays a role in regulating circadian rhythms. A pinealoma may disrupt production of this hormone, and insomnia

Insomnia

Insomnia is most often defined by an individual's report of sleeping difficulties. While the term is sometimes used in sleep literature to describe a disorder demonstrated by polysomnographic evidence of disturbed sleep, insomnia is often defined as a positive response to either of two questions:...

 may result.

Frequently, paralysis of upward gaze along with several ocular findings known collectively as Parinaud's syndrome

Parinaud's syndrome

Parinaud's Syndrome, also known as dorsal midbrain syndrome is a group of abnormalities of eye movement and pupil dysfunction. It is caused by lesions of the upper brain stem and is named for Henri Parinaud , considered to be the father of French ophthalmology...

 are the only physical symptoms seen. This is caused by the compression of the vertical gaze center in the midbrain tectum at the level of the superior colliculus and cranial nerve III. Patients may also present with pupillary disturbances and eyelid retraction (Collier's sign).

A pinealoma may cause interruption of hypothalamic inhibiting pathways, sometimes leading to beta-hCG secretion and consequent Leydig's cell stimulation.

Other symptoms may include hydrocephalus

Hydrocephalus

Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

, gait disturbances, and precocious puberty

Precocious puberty

As a medical term, precocious puberty describes puberty occurring at an unusually early age. In most of these children, the process is normal in every respect except the unusually early age, and simply represents a variation of normal development. In a minority of children, the early development is...

.

Etiology

Pinealomas can be due to proliferation of primary pineocytes (pineocytomas, pineoblastomas), astrocyte

Astrocyte

Astrocytes , also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord...

s (astrocytoma

Astrocytoma

Astrocytomas are a type of neoplasm of the brain. They originate in a particular kind of glial-cells, star-shaped brain cells in the cerebrum called astrocytes. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs...

), or germ cell

Germ cell

A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate near the gut of an embryo and migrate to the developing gonads. There, they undergo cell division of two types, mitosis and meiosis, followed by...

s (germinoma

Germinoma

A germinoma is a type of germ cell tumor which is not differentiated upon examination. It may be benign or malignant.-Classification:The term germinoma most often has referred to a tumor in the brain that has a histology identical to two other tumors: dysgerminoma in the ovary and seminoma in the...

). Germinomas are the most common tumor in the pineal gland.

Prognosis

Of the different types of pinealomas, the type with the most favorable prognosis is the pineocytoma

Pineocytoma

Pineocytoma, also known as a pinealocytoma, is a benign, slowly-growing tumor of the pineal gland. Unlike the similar condition pineal gland cyst, it is uncommon.-Diagnosis:Pineocytomas are diagnosed from tissue, i.e...

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