Choroid plexus papilloma

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

Synonyms and keywords: Choroid plexus papillomas; Papilloma of choroid plexus; Papilloma of the choroid plexus; CPP

Overview

Choroid plexus papilloma was first described by Guerard, in 1832.Choroid plexus papilloma may be classified into two groups: typical and atypical.

Historical Perspective

Choroid plexus papilloma was first described by Guerard, in 1832.

Classification

Choroid plexus papilloma may be classified into two groups:

Choroid plexus papilloma

Typical

Atypical

WHO grade I

WHO grade II

Pathophysiology

• Choroid plexus papilloma is neuroectodermal in origin and similar in structure to a normal choroid plexus. They may be created by epithelial cells of the choroid plexus.
• It may be a true congenital intracranial neoplasm.

Choroid plexus papilloma may be associated with:

• Aicardi syndrome
• Von Hippel-Lindau disease
• Li-Fraumeni syndrome
• On gross pathology, choroid plexus papilloma is characterized by a soft, solid, pink to red, capsulated, vascular, and friable cauliflower-like mass.
• Unlike most other brain tumors which are more common in the posterior fossa in children and supratentorial compartment in adults, the relationship is reversed for choroid plexus papillomas:

• Adults: 70% occur in the fourth ventricle
• Children: most often occur in the lateral ventricles, with a predilection for the trigone

• Third ventricular, cerebellopontine angle, parenchymal and even pineal region tumors have also been described.

Gallery

• 

  _{Gross pathological specimen of choroid plexus papilloma.}

Microscopic Pathology

• On microscopic histopathological analysis, choroid plexus papilloma is characterized by papillary structures with a delicate fibrovascular core lined by columnar or cuboidal epithelial cells with vesicular nuclei. Its appearance is very similar to normal choroid plexus.
• If two or more mitoses are present per 10 high power field (HPF), then the tumor is designated an atypical choroid plexus papilloma and is classified as a WHO grade II tumor.

Gallery

• 

  _{Shown above is a micrograph of choroid plexus papilloma (H&E stain).}

Causes

• There are no established causes for choroid plexus papilloma.

Differentiating Choroid Plexus Papilloma from other Diseases

Choroid plexus papilloma may be differentiated from:

• Choroid plexus carcinoma
• Choroid plexus metastasis

Among children, choroid plexus papilloma must be differentiated from:

• Medulloblastoma
• Atypical teratoid rhabdoid tumor (AT/RT)
• Papillary anaplastic ependymoma
• Pineocytoma
• Pineoblastoma

Among adults, choroid plexus papilloma must be differentiated from:

• Intraventricular meningioma
• Subependymoma
• Central neurocytoma

Epidemiology and Demographics

Prevalence

• Choroid plexus papilloma accounts for approximately 1% of all brain tumors, 2-6% of all pediatric brain tumors, and 0.5% of the adult brain tumors.
• They are far more common than the more aggressive choroid plexus carcinoma (WHO grade III), which they outnumber 5:1.

Age

• Choroid plexus papilloma is a rare disease that tends to affect children and adults.
• Approximately 85% of all choroid plexus papilloma occurs in children under the age of 5 years.

Gender

• Males are more commonly affected with choroid plexus papilloma than females. The male to female ratio is approximately 2.8 to 1.

Risk Factors

• There are no established risk factors for choroid plexus papilloma.

Screening

• There is insufficient evidence to recommend routine screening for choroid plexus papilloma.

Natural History, Complications and Prognosis

• If left untreated, patients with choroid plexus papilloma may progress to develop seizures, hydrocephalus, focal neurological deficits, cranioneuropathies, psychosis, and coma.
• Common complications of choroid plexus papilloma include CSF seeding, obstructive hydrocephalus, blindness, psychosis, and coma. The prognosis is excellent, and the 5-year survival rate after complete excision of choroid plexus papilloma is approximately 100%.

Diagnosis

Symptoms

When evaluating a patient for choroid plexus papilloma, you should take a detailed history of the presenting symptom (onset, duration, and progression), other associated symptoms, and a thorough family and past medical history review. Other specific areas of focus when obtaining the history include the review of common associated conditions such as Aicardi syndrome, Von Hippel-Lindau disease, and Li-Fraumeni syndrome. Symptoms of choroid plexus papilloma include headache, vomiting, seizures, and vision loss.

Physical Examination

Common physical examination findings of choroid plexus papilloma include:

HEENT

• Bulging fontanelle
• Enlarged head size
• Papilledema
• Homonymous hemianopia
• Mild upward gaze paresis
• Facial asymmetry

Neurological

• Altered mental status
• Gait ataxia
• Focal neurological deficits
• Cerebellar signs
• Cranioneuropathies

• 6^th and 7^th nerve palsy

Laboratory Findings

• There are no specific laboratory findings associated with choroid plexus papilloma.
• Other laboratory findings consistent with the diagnosis of choroid plexus papilloma is immunohistochemistry.

Immunohistochemistry

• Choroid plexus papilloma is demonstrated by positivity to tumor marker such as cytokeratin (CK7).
• Some reactivity for GFAP and epithelial membrane antigen may be present.

Imaging Findings

CT

• Head CT scan is helpful in the diagnosis of choroid plexus papilloma.
• On CT scan, choroid plexus papilloma is characterized by:

• Well-defined lobulated masses
• Iso- or somewhat hyperdense compared to the adjacent brain
• Associated hydrocephalus
• Fine, speckled calcification (25%)
• Microhemorrhage
• Intense homogenous enhancement, with an irregular frond-like pattern

• If there is markedly heterogeneous contrast enhancement, a choroid plexus carcinoma should be suspected

Gallery

• 

  _{The mass is relatively well circumscribed, slightly hyperdense compared to grey matter on CT, and following administration of contrast demonstrates vivid enhancement.}

MRI

• Brain MRI is helpful in the diagnosis of choroid plexus papilloma.
• On MRI, choroid plexus papilloma is characterized by:

MRI component	Findings
T1	Iso- to hypointense compared to adjacent brain
T2	Iso- to hyperintense Small flow-voids may be observed within the tumor
T1 with contrast	Marked homogenous enhancement

Gallery

• 

  _{Brain MRI T1 with contrast image demonstrates a vividly but heterogeneously enhancing mass in the right side of the 4th ventricle is associated with significant surrounding edema and mass effect. There is ventricular enlargement consistent with non-communicating hydrocephalus.}

• 

  _{Axial T2-weighted MRI image demonstrates a 17 x 16 x 17 mm hyperintense mass within the floor of the fourth ventricle. No extension into the foramen of Luschka is observed.}

Other Diagnostic Studies

• [Disease name] may also be diagnosed using [diagnostic study name].
• Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].

Treatment

Medical Therapy

• There is no treatment for [disease name]; the mainstay of therapy is supportive care.
• The mainstay of therapy for [disease name] is [medical therapy 1] and [medical therapy 2].
• [Medical therapy 1] acts by [mechanism of action1].
• Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].

Surgery

• Surgery is the mainstay of therapy for [disease name].
• [Surgical procedure] in conjunction with [chemotherapy/radiation] is he most common approach to the treatment of [disease name].
• [Surgical procedure] can only be performed for patients with [disease tage] [disease name].

Prevention

• There are no primary preventive measures available for [disease name].
• Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
• Once diagnosed and successfully treated, patients with [disease name] are followedup every [duration]. Followup testing includes [test 1], [test 2], and [test 3].

References

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