A pinealoma is a tumor of the
pineal gland
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep, sleep patterns in both circadian rhythm, circ ...
, a part of the brain that produces
melatonin
Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle.
In vertebrates ...
. 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. In a minority of childr ...
.
Signs and symptoms
The pineal gland produces the hormone
melatonin
Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle.
In vertebrates ...
which plays a role in regulating
circadian rhythms
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to ...
. A pinealoma may disrupt production of this hormone, and
insomnia
Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...
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 an inability to move the eyes up and down. It is caused by compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). The eyes lose the ability to move upward and ...
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 forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...
tectum
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', "m ...
at the level of the
superior colliculus
In neuroanatomy, the superior colliculus () is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form ''tectal'' is commonly ...
and
cranial nerve III
The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements o ...
. 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 an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...
,
gait disturbance
Gait deviations are nominally referred to as any variation of standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Lower-limb amputees are unable to maintain the characteristic walking pattern ...
s, and
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. In a minority of childr ...
.
Cause
Pinealomas can be due to proliferation of primary
pineocytes (
pineocytomas
Pineocytoma, 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. a brain biopsy.They consist of:
* Cytopathology, cytological ...
, pineoblastomas),
astrocyte
Astrocytes (from Ancient Greek , , "star" + , , "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 endo ...
s (
astrocytoma
Astrocytomas are a type of brain tumor. 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 usu ...
), or
germ cell
Germ or germs may refer to:
Science
* Germ (microorganism), an informal word for a pathogen
* Germ cell, cell that gives rise to the gametes of an organism that reproduces sexually
* Germ layer, a primary layer of cells that forms during embry ...
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 pro ...
).
Germinomas are the most common tumor in the pineal gland.
Image:Tumor_Pineocytoma2.JPG,
Image:Tumor_Pineocytoma3.JPG,
Diagnosis
Treatment
Prognosis
Of the different types of pinealomas, the type with the most favorable prognosis is the
pineocytoma
Pineocytoma, 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. a brain biopsy.They consist of:
* Cytopathology, cytological ...
.
References
External links
*
{{Endocrine gland neoplasia
Endocrine neoplasia
Brain tumor