A pinealoma is a tumor of the

pineal gland The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep, sleep patterns following the diurnal c ...

, a part of the brain that produces

melatonin Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cow ...

. If a pinealoma destroys the cells of the pineal gland in a child, it can cause

precocious puberty In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. There is early developm ...

Signs and symptoms

The pineal gland produces the hormone

which plays a role in regulating

circadian rhythms A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment (is entrai ...

. A pinealoma may disrupt production of this hormone, and

insomnia Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...

may result. Frequently, paralysis of upward gaze along with several ocular findings such as convergence retraction nystagmus and eyelid retraction also known as Collier's sign and Light Near Dissociation (pupil accommodates but doesn't react to light) are known collectively as

Parinaud's syndrome Parinaud's syndrome is a constellation of neurological signs indicating injury to the dorsal midbrain. More specifically, compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). It ...

or Dorsal Mid-brain syndrome, are the only physical symptoms seen. This is caused by the compression of the vertical gaze center in the

midbrain The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

tectum The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

at the level of the

superior colliculus In neuroanatomy, the superior colliculus () is a structure lying on the tectum, roof of the mammalian midbrain. In non-mammalian vertebrates, the Homology (biology), homologous structure is known as the optic tectum or optic lobe. The adjective f ...

and cranial nerve III. Work-up usually includes Neuro-imaging as seen on the right. A pinealoma may cause interruption of hypothalamic inhibiting pathways, sometimes leading to beta-hCG secretion and consequent Leydig's cell stimulation (endocrine syndrome). Other symptoms may include

hydrocephalus Hydrocephalus is a condition in which cerebrospinal fluid (CSF) builds up within the brain, which can cause pressure to increase in the skull. Symptoms may vary according to age. Headaches and double vision are common. Elderly adults with n ...

gait disturbance Gait deviations are nominally referred to as any variation of gait (human), standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Amputation, Lower-limb amputees are unable to maintain the charac ...

s, and

Cause

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

astrocyte Astrocytes (from Ancient Greek , , "star" and , , "cavity", "cell"), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical control of en ...

s (

astrocytoma Astrocytoma is a type of brain tumor. Astrocytomas (also astrocytomata) originate from a specific kind of star-shaped glial cell in the cerebrum called an astrocyte. This type of tumor does not usually spread outside the brain and spinal cord, an ...

), or

germ cell A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they unde ...

s (

germinoma A germinoma is a type of germ-cell tumor, which is not differentiated upon examination. It may be benign or malignant. Cause Germinomas are thought to originate from an error of development, when certain primordial germ cells fail to migrate pr ...

). Germinomas are the most common tumor in the pineal gland. Image:Tumor_Pineocytoma2.JPG, Image:Tumor_Pineocytoma3.JPG,

Diagnosis

Treatment

Some pinealomas are treated by

radiotherapy Radiation therapy or radiotherapy (RT, RTx, or XRT) is a treatment using ionizing radiation, generally provided as part of cancer therapy to either kill or control the growth of malignant cells. It is normally delivered by a linear particle ...

, since surgical removal may be impossible due to the location. Radiotherapy can be successful in killing the tumour, and 50% of patients undergoing it survive to old age.

Prognosis

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

References

External links

* {{Endocrine gland neoplasia Endocrine neoplasia Brain tumor