Choroid plexus tumors arise from the choroid plexus in the ventricles of the brain. They range from benign choroid plexus papillomas (CPP, WHO grade I) to atypical choroid plexus papillomas (WHO grade II) and malignant choroid plexus carcinomas (CPC, WHO grade III). CPPs typically present with symptoms of increased intracranial pressure due to hydrocephalus in children. On imaging, CPPs enhance strongly with contrast. Surgical resection is the primary treatment, with the goal of total removal while preserving neurological function.

1. CHOROID PLEXUS
PAPILLOMAS

2. INTRODUCTION:
 Choroid plexus tumors are benign or malignant neoplasms that arise from the specialized tissues
of the choroid plexus.
 The choroid plexus develops from the specialization of ventricular ependymal cells along certain
segments of the neural tube and is present within each of the four ventricles.
 it accounts for 0.5% to 0.6% of all brain tumors.
 Majority occur in children
 Supra tentorial tumors (in the lateral and third ventricles) occurred mostly in infants
 In adults these are usually infra tentorial (fourth ventricle and cerebellopontine angle)
 50% of tumors situated in the lateral ventricles, 37% in the fourth ventricle, 9% in the third
ventricle, and the remainder in other locations.

3. CHOROID PLEXUS

4. Blood supply:
 tumors of the lateral ventricle or third ventricle are
generally supplied by branches of the anterior or posterior
choroidal arteries.
 A fourth ventricular tumor receives its blood supply from
medullary or vermian branches of the posterior inferior
cerebellar artery.

5. Classification:
WHO grade I
CHOROID PLEXUS
PAPILLOMAS (CPP)
WHO grade II
ATYPICAL CHOROID
PLEXUS PAPILLOMAS
WHO grade III
CHOROID PLEXUS
CARCINOMAS (CPC)
Histologically benign histologic features similar to
those of CPPs, but the mitotic
activity is increased.
Malignant tumor that invades
adjacent brain and metastasize
through CSF.
fewer than two mitotic figures
per 10 high-power fields
more than two mitotic figures but
fewer than 5 per 10 highpower
fields
more than five mitotic figures per
10 high-power fields.
The microscopic appearance of
CPPs is similar to that of the
normal choroid plexus The
prominent papillary structure is
composed of simple cuboidal or
columnar epithelia.

6. CHOROID PLEXUS CARCINOMA:
The definitive diagnosis of a CPC is usually based upon three major histopathologic features:
1. The cytologic criteria of malignancy, such as nuclear atypia, increased nucleus-
to-cytoplasm ratio, and prominent mitotic figures
2. the loss of the normal papillary architecture
3. Evidence of brain invasion with extension of the tumor through the ependymal
lining of the ventricle.

7. Clinical Features:
The most common presentation of choroid plexus neoplasms is related to increased intracranial
pressure (ICP) secondary to hydrocephalus.
SYMPTOMS SIGNS
nausea/vomiting macrocephaly
irritability papilledema
headache decreased level of consciousness
visual difficulty
seizure
Difficulty in mentation and occasional
headache might be the only symptoms in
adults

8. PATHOGENESIS OF HYDROCEPHALUS:
Ventricular enlargement is seen in
most but not all choroid plexus
papillomas. This may be due to
combination of factors:
◦ Overproduction of CSF
◦ Obstruction of CSF pathways by
tumor mass
◦ Subarachnoid scarring due to
recurrent bleeding from tumor

9. NEUROIMAGING:
CT SCAN BRAIN:
 Features of hydrocephalus.
 On non contrast ct scan its similar in density to brain tissue.
 There is dramatic enhancement with contrast CT scan.

11. ◦ Papillomas appear isodense in relation to brain tissue on T1-weighted images
◦ These tumors enhance homogeneously and intensely with contrast material,
which reflects an excellent blood supply.
◦ Areas of high signal indicate hemorrhage necrosis.
◦ An enlarged choroidal artery leading into the tumor mass can sometimes be
seen in contrast-enhanced images.
◦ T2-weighted images demonstrate intermediate to high signal intensity with
areas of heterogeneous internal signals
◦ In case of CPCs, the border between tumor and normal brain tissue appears
diffuse, which may reflect areas of brain invasion.
MRI BRAIN:

14. A large left ventricular choroid plexus papilloma in an 18-month-old girl. A, T1- weighted image with
gadolinium enhancement. B, T2-weighted axial image. C, Magnetic resonance angiogram demonstrating a
choroidal artery arising from the posterior cerebral artery and leading to the tumor. D, Postoperative coronal T1-
weighted image. The surgical route was through the temporal lobe to first access the feeding artery prior to
tumor resection.

16. Magnetic resonance imaging comparisons of choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). A, T2-weighted axial section. A CPP is
accompanied by significant adjacent cerebral edema. Some consistent fine structure is visible inside the tumor. There may be some brain invasion at the lateral
edge of the tumor. B, T2-weighted axial section. This CPC is also accompanied by significant adjacent brain edema. The structure within the tumor is much less
defined. There may be brain invasion laterally, but the tumor appears generally distinct from the brain. C, T1-weighted, gadolinium-enhanced axial section. The
CPP enhances nearly uniformly and demonstrates a small lobular structure. The edges are distinct from the surrounding brain. D, T1-weighted,
gadoliniumenhanced axial section. The CPC also enhances brightly but with much less regularity within the tumor. The fine lobules are not visible in the
papilloma. There is no clear site of brain invasion.

17. Magnetic resonance spectroscopy:
 Magnetic resonance spectroscopy of CPP and CPC is
characterized by a prominent choline peak and absence of N-
acetyl aspartate.
Myo-inositol level is also reported to be specifically
increased in CPPs.

18. TREATMENT:
The treatment of CPP is total surgical excision. Subtotal
removal and radiotherapy play no role.
The following steps are part of most surgical plans:
(1) temporary or permanent resolution of hydrocephalus.
(2) identification of the arterial supply.
(3) planning the surgical approach to allow access to the
vascular supply and maximal exposure of the tumor

19. APPROACHES
1. Fourth ventricle tumors => midline suboccipital approach
2. Third ventricle tumors => transcallosal/ transfrontal cortical approach
3. Lateral ventricle tumors => transcortical via temporoparietal craniotomy

20. LATERAL VENTRICLE TUMORS
 a direct cerebrotomy posterior to the angular gyrus allows access to the entire trigone.
 For more anterior tumors, an incision can be made in the frontal convolutions and the lateral
ventricle approached from an anterolateral direction.
 it can also be approached through a cerebrotomy through the superior or middle temporal gyri.
 Tumors located within the temporal horn are easily approached through the middle or inferior
temporal gyri.

23. Adjuvant Therapy
Although a number of trials have involved the use of various chemotherapy regimens, no
regimen is standard
 patients with CPC and atypical CPC can be treated with
 etoposide
 vincristine
 carboplatin
 Cyclophosphamide
 In one meta-analysis, of these drugs, etoposide was shown to have the highest response rate.

24. Thank you