Pineocytoma Pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2] Homa Najafi, M.D.[3]

## Overview[edit | edit source]

The exact pathogenesis of [disease name] is not fully understood.

It is thought that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].

[Pathogen name] is usually transmitted via the [transmission route] route to the human host.

Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.

[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].

The progression to [disease name] usually involves the [molecular pathway].

The pathophysiology of [disease/malignancy] depends on the histological subtype.

## Pathophysiology[edit | edit source]

### Physiology[edit | edit source]

The normal physiology of [name of process] can be understood as follows:

### Pathogenesis[edit | edit source]

* The exact pathogenesis of [disease name] is not completely understood.

* It is understood that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
* [Pathogen name] is usually transmitted via the [transmission route] route to the human host.
* Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
* [Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].
* The progression to [disease name] usually involves the [molecular pathway].
* The pathophysiology of [disease/malignancy] depends on the histological subtype.

## Genetics[edit | edit source]

[Disease name] is transmitted in [mode of genetic transmission] pattern.

Genes involved in the pathogenesis of [disease name] include:

* [Gene1]
* [Gene2]
* [Gene3]

The development of [disease name] is the result of multiple genetic mutations such as:

* [Mutation 1]
* [Mutation 2]
* [Mutation 3]

## Associated Conditions[edit | edit source]

Conditions associated with [disease name] include:

* [Condition 1]
* [Condition 2]
* [Condition 3]

## Gross Pathology[edit | edit source]

On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].

## Microscopic Pathology[edit | edit source]

On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].

## Pathophysiology[edit | edit source]

### Pathogenesis[edit | edit source]

* Due to the pineal gland's location, any tumor or cyst formation would lead to the compression of the aqueduct of Sylvius.
* The aqueduct of Sylvius allows the cerebrospinal fluid to circulate out.
* When there is a blockage in aqueduct of Sylvius by an abnormal pineal gland, the passage of the duct is blocked, and CSF pressure builds up, leading to hydrocephalus.
* Results in nausea, vomiting, visual changes, headaches, seizures, and memory changes.
* Increase in intracranial pressure can even be life-threatening, prompting emergency treatment.
* The hydrocephalus can be relieved by the placement of a VP shunt or ventriculostomy.
* Vision changes would also occur due to an involvement of the tectal region.
* The tectal region helps dictate eye movements.
* Fault in the tectal region causes double vision, an issue with focusing on objects, and eye movement impairment.
* The pineal gland can cause Parinaud syndrome due to the increasing size of the gland compressing the pretectal area and superior colliculi of the midbrain.
* Parinaud syndrome prevents a person from moving his or her eyes up and down.
* The thalamus can be affected, and if so, there can be disturbances on that side of the body which would result in weakness and loss of sensation.
* The tumor's effect on the hypothalamus will lead to weight gain, disruption of sleep, disruption of temperature control, and water regulation.
* Cerebellar involvement would result in motor impairment.
* If the tumor of the pineal gland is present in childhood, then endocrine dysfunctions can also result such as precocious pseudopuberty, diabetes insipidus, and a slowed growth rate.

### Gross Pathology[edit | edit source]

On gross pathology, pineocytoma is characterized by solid, sometimes with focal areas of cystic change, gray, well-circumscribed mass with or without hemorrhage.[1][2]

### Microscopic Pathology[edit | edit source]

On microscopic histopathological analysis, pineocytoma is characterized by:[3]

* Cytologically benign cells (uniform size of nuclei, regular nuclear membrane, light chromatin)
* Pineocytomatous/neurocytic rosette, which is an irregular circular/flower-like arrangement of cells with a large meshwork of fibers (neuropil) at the center.

Intermediate magnification micrograph of a pineocytoma. HPS stain.[4]

### Immunohistochemistry[edit | edit source]

Pineocytoma is demonstrated by positivity to tumor markers such as:[5][6][7][8]

* Synaptophysin
* Neuron-specific enolase
* GFAP
* Chromogranin A
* PLAP
* Ki-67
* Beta tubulin III

## References[edit | edit source]

1. ↑ Pathology and radiographic features of pineocytoma. Dr Bruno Di Muzio and Dr Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/pineocytoma. Accessed on November 18, 2015
2. ↑ Gross description of pineocytoma. Pathology Outlines 2015. http://pathologyoutlines.com/topic/cnstumorpineocytoma.html. Accessed on November 20, 2015
3. ↑ Microscopic features of pineocytoma. Libre Pathology 2015. http://librepathology.org/wiki/index.php/Pineal_gland#Pineocytoma. Accessed on November 18, 2015
4. ↑ Microscopic images of pineocytoma. Libre Pathology 2015. http://librepathology.org/wiki/index.php/Pineal_gland#Pineocytoma. Accessed on November 18, 2015
5. ↑ Microscopic description of pineocytoma causing hydrocephalus. Dr Frank Gaillard. Radiopaedia 2015. http://radiopaedia.org/cases/pineocytoma-causing-hydrocephalus. Accessed on November 20, 2015
6. ↑ Histology of pineocytoma. Dr Frank Gaillard. Radiopaedia 2015. http://radiopaedia.org/cases/pineocytoma-with-astrocytic-differentiation-1. Accessed on November 20, 2015
7. ↑ IHC features of pineocytoma. Libre Pathology 2015. http://librepathology.org/wiki/index.php/Pineal_gland#Pineocytoma. Accessed on November 20, 2015
8. ↑ Hirato, Junko; Nakazato, Yoichi (2001). Journal of Neuro-Oncology. 54 (3): 239–249. doi:10.1023/A:1012721723387. ISSN 0167-594X. Missing or empty `|title=` (help)

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