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Tumor Discovery Choroid plexus tumors: Benign to malignant

is more highly expressed in fourth ventricle tumors than growing residual CPPs, while chemotherapy can be used
lateral ventricle tumors. CPPs are most commonly found to prevent recurrence and improve survival . Although
[52]
in the lateral ventricle, occurring in 50% of pediatric recurrence is rare, cases of craniospinal seeding and
patients, and in the fourth ventricle, observed in 40% of suprasellar metastases have been reported .
[60]
adult patients . Other reported that sites of occurrence Post-operative complications include persistent features
[25]
include the brain stem, cerebellopontine angle, pineal of hydrocephalus and increased intracranial pressure,
region, posterior fossa, posterior third ventricle, sacral resulting in a range of visual defects from papilledema
canal, and sellar region [25,39-44] . and optic atrophy to visual loss. Other complications
As a result of CPPs, arachnoid granulation is blocked include cognitive defects, seizures, bleeding, and CSF
due to CSF overproduction or hemorrhage. This direct rhinorrhea [54,61-63] .
mechanical obstruction of CSF causes hydrocephalus and
associated clinical symptoms [8,45] . The clinical presentation 2.3. Atypical choroid plexus papilloma
can vary, ranging from headache, hemifacial spasm, or Atypical choroid plexus papillomas are an intermediate
CSF rhinorrhea to hydrocephalus [45,46] . Due to the rapid subtype of CPTs that demonstrate intermediate histology,
growth observed in CPPs and the anatomy of the cerebral specifically mitotic activity, between CPPs and CPCs [27,64] .
ventricular system, more severe symptoms requiring The median age of diagnosis for aCPPs is between 8.4 and
earlier intervention are found in CPPs located in the fourth 12 months, although there are reports of aCPPs occurring
ventricle [8,47] . in adults [59,65-68] . Many aCPPs were misdiagnosed as either
Prenatal ultrasound and neurosonogram through CPPs or CPCs before the WHO classified them into
an unfused anterior fontanelle will demonstrate their own category in 2007. Consequently, the reported
echogenic lesions with the bidirectional flow in the incidence was lower than that of CPPs and CPCs.
ventricles throughout diastole . CT scans demonstrate The WHO classifies aCPPs as grade II CPTs with
[48]
ventriculomegaly with hyper- to isodense lobulated lesions 2 – 5 mitotic figures per 10 HPFs [27,64] . Compared to CPP,
and slightly irregular margins within the ventricles . aCPPs demonstrate necrosis, brisk mitotic activity, and
[49]
Calcifications can be observed in about 25% of patients. increased cell density and nuclear pleomorphism . These
[68]
MRI demonstrates flow voids and enhanced well-defined features contribute to early metastases observed in aCPPS,
intraventricular lesions. The masses are lobulated and which pose 5 times increased risk of recurrence at 5 years .
[23]
frond-like, appearing hypointense and hyperintense on Microscopy also reveals portions of papillary growth
axial spin-echo T1-weighted images (T1WI) and axial fast consisting of cuboidal to columnar cells . Grossly, aCPPs
[67]
spin-echo T2-weighted images (T2WI), respectively [50,51] . are friable, soft, globular masses with irregular projections,
Radiosurgery may be considered a possible treatment and high vascularity [37,67] . Immunohistochemistry findings
option, but the definitive treatment for CPPs is surgical can vary from case to case. Atypical CPPs were positive for
[68]
resection, sometimes complemented with adjuvant S-100, synuclein, and vimentin . The lateral ventricle is
chemotherapy [52,53] . However, the timing of surgery can vary the primary site of occurrence for aCPPs, with other less
based on the patient’s presentation and symptoms . In common locations including the third and fourth ventricle.
[54]
asymptomatic patients, treatment options include prompt In some cases, aCPPs have been reported in the cerebral
[66,68]
removal, removal on radiographic changes on follow-up hemispheres, unrelated to the ventricular system .
imaging, or removal when symptoms manifest. Tumor The clinical symptoms associated with aCPPs are likely
resection is easier in the setting of hydrocephalus, but a result of the same pathophysiology observed in CPPs
waiting for the development of hydrocephalus can result due to their similar morphology and behavior [8,45] . The
in subarachnoid hemorrhage, seizures, cognitive defects, clinical presentation is a combination of symptoms caused
or mass effect-induced focal defects [52,54,55] . Pre-operative by hydrocephalus and increased intracranial pressure or
embolization and percutaneous stereotactic intratumoral neurological symptoms resulting from the mass effect.
embolization with a sclerosing agent are approaches used These symptoms include headache, gait disturbances,
to reduce blood flow and optimize tumor resectability [56,57] . vertigo, diplopia, and paresis [66,68,69] . CT and MRI scan
This is particularly important in pediatric patients, as findings in aCPPs are similar to those seen in CPPs as well.
blood loss is a leading contributor to the perioperative However, MRI findings in aCPPs are more likely to show
mortality rate (12%) during surgical resection of CPPs in cysts, necrotic changes, peritumoral edema, unclear tumor
st
the 1 year of life . However, surgical outcomes and cure boundaries, and larger volume masses. In addition, masses
[58]
rates approach 100% in infants and young children up to are isointense, hyperintense, and isointense on T1WI, T2WI,
4 years old . Presurgical irradiation can also be used for and diffusion-weighted images (DWI), respectively [48,49,68] .
[59]
Volume 2 Issue 2 (2023) 3 https://doi.org/10.36922/td.1057