Choroid plexus papilloma

View Details

Status

Done

Parent item

Choroid plexus tumours

Definition

• Essential:
• Demonstration of choroid plexus differentiation by histopathological and immunophenotypic features AND
• Absent or low mitotic activity AND
• Intraventricular or cerebellopontine angle location

Numbers

• 0.4-0.6% of all intracranial tumors.

• 58.2% of the choroid plexus tumours

• 3% of childhood brain tumors

• Gender: male-to-female ratio is 1.2:1
• For lateral ventricle tumours 1:1,
• For fourth ventricle tumours 3:2.

• Age:
• In children: Mainly a childhood cancer (80%, in <20 yrs)
• 80% occur in the trigone or atria of the lateral ventricle
• Adults:
• 4th ventricle
• 4th ventricle tumours are evenly distributed across all age groups.

• Multiple sites in 3.7% of cases

CNS WHO grading

• Grade I

Origin

• OTX2 and TRPM3 (genes involved in the development of choroid epithelium) mutations

Localisation

• Ventricular system where the normal choroid plexus can be found.
• Lateral ventricle (43%)
• Fourth ventricle (39%)
• Third ventricle (11%)
• Cerebellopontine angle cistern (7%)

• Median age:
• 1.5 years for tumours in the lateral and third ventricles,
• 22.5 yrs for 4th
• 35.5 yrs CP angle

Histopathology

Macroscopic

Microscopic

• Circumscribed cauliflower-like masses that may adhere to the ventricular wall, but are usually well delineated from brain parenchyma

• Delicate fibrovascular connective tissue fronds are covered by a single layer of uniform cuboidal to columnar epithelial cells with round or oval, basally situated monomorphic nuclei

• Histology does not predict behaviour

• Low mitotic

• +:
• CAM 5.2 (94%)
• Transthyretin (89%)
• Vimentin,
• S100 (54%)
• Most demonstrate positive staining for CK7, and positivity for CK20 is less common.
• Fibrovascular core is positive for type IV collagen, reticulin and laminin
• Potassium channel KIR7.1.
• Glutamate transporter EAAT1

Genetic

• MGMT promoter methylation presence

• Choroid plexus papilloma is a major diagnostic feature of Aicardi syndrome
• Aicardi's syndrome
• An X-linked disorder
• Sporadic condition
• Triad of
• Total or partial agenesis of the corpus callosum
• Infantile spasms
• Chorioretinal lacunae
• Well-defined, punched-out lesions in the pigmented layer of the retina, most commonly found around the optic disc.
• They represent areas where both the retina and the underlying choroid are absent or markedly atrophic, creating distinctive patches that appear darker upon examination

• Abnormal electroen-cephalogram use to support diagnosis

Presentation

• Hydrocephalus (papilledema, inc. head circumference, papilledema)
• Excess production of CSF
• Block CSF pathways

Investigation

• Needle biopsy not recommended since histologically resembles normal choroid plexus

Radiological

CT

• Isodense or hyperdense (calcification)

• Mulberry appearance

 

MRI

• T1-isointense

• T2-hyperintense, irregularly contrast-enhancing, well-delineated masses within the ventricles
• Small flow void

MRS

• Choroid plexus papillomas
• Elevated myoinositol peak

Prognosis

• Cured by complete surgical resection
• Gross vs subtotal resection (100% vs 68%).

• High survival (5-year survival rate as high as 100%) sunless becomes malignant (then 5 year survival is 26%) although

• Even benign choroid plexus papilloma may seed cells into the cerebrospinal fluid;

• In rare cases, this can result in drop metastases in the surroundings of the cauda equina

• 10 - 30% become histologically malignant

Differential diagnosis

• Intraventricular meningioma

• Central neurocytoma

• Choroid plexus carcinoma
• MRI
• More heterogeneous in appearance than are choroid plexus papillomas
• Usually extend beyond the margins of the ventricle
• MRS
• More often associated with an elevated choline peak.

Treatment (CCLG)

Surgery

• Pre op
• Correction of hydrocephalus
• CTA/DSA
• Pre op embolization

• Aim
• Maximal safe surgical resection.

• Technique
• High bleeding risk needs cross match

• Post op
• Surgical surveillance for localised CPP.
• If there is local progression,
• Second surgery should be considered.
• After 3rd surgery need chemo
• Complete remission
• Then consider a watch and wait policy.

Chemotherapy

• Indication
• Progressive, inoperable residual disease or it is the third resection, then proceed with chemotherapy as per treatment for localised APP with residual disease (> 3 years).
• Metastatic tumours post surgical resection of primary tumour

• Options
• 2 cycles of CarbEV (Carboplatin / Etoposide / Vincristine) chemotherapy.
• If there is chemotherapy response or stable disease, then complete 6 cycles of CarbEV, then watch and wait without giving radiation.
• Assessment should be made every 2 cycles in case a complete response is achieved, and discontinuation of chemotherapy may be considered.
• If progressive disease consider further surgery and second line chemotherapy, with radiation only in exceptional cases.

Radiotherapy

• Indication
• Rarely used
• Only used when surgical and chemotherapy options are exhausted
• Non-metastatic CPP progressing after repeated surgery and chemotherapy
• Focal radiotherapy may be indicated in those > 1.5 years of age.
• There is no robust evidence to dictate the RT approach and RT-related toxicity is considerable
• Metastatic CPP progressing after surgery and chemotherapy
• CSRT may be indicated in those > 3 years of age.
• There is no robust evidence to dictate the RT approach and RT-related toxicity is considerable
• Without Li-Fraumeni syndrome and active exclusion of TP53 mutations

• Options
• Proton therapy