Pineal yolk sac tumor

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

Synonyms and keywords: Pineal yolk sac tumors; Pineal yolk sac tumour; Pineal yolk sac tumours; Pineal endodermal sinus tumor; Pineal endodermal sinus tumors; Pineal endodermal sinus tumour; Pineal endodermal sinus tumours; Pineal yolk sac carcinoma; Pineal yolk sac carcinomas; Pineal gland tumor; Germ cell tumor; Brain tumor

Overview

• Pineal yolk sac tumor is a rare type of extra gonadal yolk sac tumor. They make up a small fraction of all intracranial germ cell tumors and an even small fraction of pineal masses overall.
• Pure pineal yolk sac tumors secrete AFP.
• On microscopic histopathological analysis, pineal yolk sac tumor is characterized by poorly differentiated endothelium-like, cuboidal, or columnar cells with prominent nucleoli and significant mitotic activity.
• Pineal yolk sac tumor is demonstrated by positivity to tumor markers such as AFP, cytokeratin, and AAT. PAS-diastase positive hyaline globules and Schiller-Duval bodies are the characteristic features of pineal yolk sac tumors.
• In upto 50% of cases, these tumors co-exist with other germ cell tumors.
• Pineal yolk sac tumor may be associated with Down syndrome.
• Common complication of pineal yolk sac tumor includes obstructive hydrocephalus.
• Prognosis of pineal yolk sac tumor is generally poor.
• Symptoms of pineal yolk sac tumor include headache, nausea, vomiting, weakness, confusion, and somnolence.
• Head CT scan and brain MRI may be helpful in the diagnosis of pineal yolk sac tumor.
• On head CT scan, pineal yolk sac tumor is characterized by a hypodense, heterogenous mass in the pineal region with signs of obstructive hydrocephalus.
• On brain MRI, pineal yolk sac tumor is characterized by hypointensity on T1-weighted images and hyperintensity on T2-weighted images. There may be enhancement after contrast administration.
• Biopsy is generally done to confirm the diagnosis of pineal yolk sac tumor.

Historical Perspective

• Tumors of brainstaim as well as pineal gland,were unoperable until late of 20th century.
• Dr Cushing reported one of the first case in 1904.
• Dr Horsley in 1905was the first who did direct surgical intervention,and in 1913 Dr Oppenhein and Krause resected pineal tumor sucssesfully.
• There are only two case Reports of pineal yolk sac tumor that are associated with Down's syndrome in English literature.

Classification

• There is so many classification system for pure pineal tumors.
• The most current system is for World Health Organization(WHO).
• Louis and associates edited classification of Central Nervous System tumors and published in 2007.

Adapted from WHO: Tumor Origin Frequency Germ Cell Tumors Rest of germ cells ~60% GerminomaMature TeratomaImmature TeratomaTeratoma with MalignantTransformationYolk sac tumor (endodermal sinus tumor)Embryonal carcinomaChoriocarcinoma Pineal Parenchymal Tumors Pineal glandular tissue ~30% Pineocytoma (WHO grade I)Pineal parenchymal tumor of intermediate differentiation (WHO grade II or III)Pinealoblastoma (WHO grade IV)Papillary tumor of pineal region Tumors of Supportive and Adjacent Structures ~10% AstrocytomaGlioma (glioblastoma or oligodendroglioma)Medulloepithelioma Glial cells EpendymomaChoroid plexus papilloma Ependymal lining Meningioma Arachnoid cells HemangiomaHemangiopericytoma or blastomaChemodectomaCraniopharyngioma Vascular cells Non-neoplastic Tumor-like Conditions <1% Arachnoid cyst Arachnoid cells Degenerative cysts (pineal cysts) Glial cells Cysticercosis Parasites Arteriovenous malformations Vascularization CavernomasAneurysms of the vein of Galen Metastases Absence of blood-brain barrier <0.1% Lung (most common), breast, stomach, kidney, melanoma

• Overal Intercranial germ cell tumors are classified in two types:

;Germinomas and Non Germinomattous
Yolk sac tomur which the other name is Endodermal sinus tomur is a non germinomatous germ cell tomur.

Pathophysiology

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

OR

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].

OR

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

OR

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

OR

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

OR

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

OR

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

Causes

Disease name] may be caused by [cause1], [cause2], or [cause3].

OR

Common causes of [disease] include [cause1], [cause2], and [cause3].

OR

The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].

OR

The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click here.

Differentiating ((Page name)) from Other Diseases

[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].

OR

[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].

Epidemiology and Demographics

The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.

OR

In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.

OR

In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.

Patients of all age groups may develop [disease name].

OR

The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.

OR

[Disease name] commonly affects individuals younger than/older than [number of years] years of age.

OR

[Chronic disease name] is usually first diagnosed among [age group].

OR

[Acute disease name] commonly affects [age group].

There is no racial predilection to [disease name].

OR

[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].

[Disease name] affects men and women equally.

OR

[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.

The majority of [disease name] cases are reported in [geographical region].

OR

[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].

Risk Factors

There are no established risk factors for [disease name].

OR

The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].

OR

Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].

OR

Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.

Screening

There is insufficient evidence to recommend routine screening for [disease/malignancy].

OR

According to the [guideline name], screening for [disease name] is not recommended.

OR

According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].

Natural History, Complications, and Prognosis

If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].

OR

Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].

OR

Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.

Diagnosis

Diagnostic Study of Choice

The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].

OR

The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].

OR

The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].

OR

There are no established criteria for the diagnosis of [disease name].

History and Symptoms

The majority of patients with [disease name] are asymptomatic.

OR

The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].

Physical Examination

Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].

OR

Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

The presence of [finding(s)] on physical examination is diagnostic of [disease name].

OR

The presence of [finding(s)] on physical examination is highly suggestive of [disease name].

Laboratory Findings

An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].

OR

Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].

OR

[Test] is usually normal among patients with [disease name].

OR

Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].

OR

There are no diagnostic laboratory findings associated with [disease name].

Electrocardiogram

There are no ECG findings associated with [disease name].

OR

An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

X-ray

There are no x-ray findings associated with [disease name].

OR

An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

Echocardiography or Ultrasound

There are no echocardiography/ultrasound findings associated with [disease name].

OR

Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

CT scan

There are no CT scan findings associated with [disease name].

OR

[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

MRI

There are no MRI findings associated with [disease name].

OR

[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

Other Imaging Findings

There are no other imaging findings associated with [disease name].

OR

[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

Other Diagnostic Studies

There are no other diagnostic studies associated with [disease name].

OR

[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].

Treatment

• The mainstay of therapy for pineal yolk sac tumor is radiotherapy and/or chemotherapy. Sometimes, surgical resection may be done.

Management Options of Penial Gland tumors
CSF diversion	The optimal surgical strategy to treat acute hydrocephalus in patients with pineal tumors is uncertain. CSF diversion (ventriculoperitoneal [VP] shunt or third ventriculostomy may be necessary in symptomatic patients, although debulking surgery may obviate the need for this procedure When CSF diversion is necessary, endoscopic third ventriculostomy can be carried out at the same time as the biopsy and is preferred over VP shunts, which can be complicated by infection, shunt malfunction, subdural hematoma, and rarely, tumor seeding
Surgical resection	Some series report long-term survival with surgery alone, even in patients with pineoblastomas. Indeed, for pineoblastomas, gross total surgical resection appears to correlate with improved survival. Patients with symptomatic recurrent pineocytomas should also be considered for surgical resection of the lesion
Radiation	Postoperative adjuvant RT is frequently (but not universally) recommended, and local control is dose-dependent. The incidence of leptomeningeal recurrence was significantly lower among patients receiving CSI compared with those who did not. The five-year survival rates were 86 and 49 percent for pineocytomas and non-pineocytoma PPTs, respectively. Adjuvant RT is not universally recommended after gross total resection of a pineocytoma
Stereotactic radiosurgery	Stereotactic radiosurgery (SRS) is emerging as a useful treatment alternative for pineocytomas, although experience is limited. The precise radiation fields that are defined by MRI or CT-computerized treatment planning minimize damage to the surrounding brain, and the risks of general anesthesia and craniotomy are avoided. SRS is increasingly being used to treat pineal region tumors, either as an additional therapy after conventional treatments or as a primary treatment. Due to the low rate of side effects, IRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant PPTs, IRS may be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.
Chemotherapy as part of multimodality therapy	The similarity of pineoblastomas to medulloblastomas in terms of their clinical behavior and tendency for leptomeningeal seeding has led to the use of similar chemotherapy regimens in patients with pineoblastoma as part of a multimodality approach. Chemotherapy has been used to delay radiation therapy in very young children, for whom the long-term neurocognitive and developmental side effects of craniospinal irradiation (CSI) are a major concern. The importance of radiation therapy as a component of the initial treatment of supratentorial primitive neuroectodermal tumors (PNETs) is also supported by the German HIT-SKK87 and HIT-SKK92 protocols, as well as the Canadian pediatric brain tumor protocol

References

Template:WikiDoc Sources