Cerebellopontine angle Choroid plexus papilloma various presentations: report of series and literature review

Choroid plexus tumors (CPTs) are rare choroid plexus epithelium originated neoplasms. Among all, choroid plexus papilloma (CPP) is the most common type of CPT. Clinical features and signs at diagnosis of CPP in CPA are so extensive and also nonspecific. This work aimed to review the sign and symptoms of CPP tumors in CPA through all cases reported in the literature. In this study, Data regarding presenting symptoms of 60 adult patients (including 53 adult patients identified from the literature and our seven new patients that presented in this study) with CPP in CPA were reviewed. Symptoms related to 8th cranial nerve, lower motor, 7th, and 5th cranial nerves were the most prevalent symptoms respectively following ICP rising and cerebellar signs. The most common symptoms were related to the ICP elevation, cerebellar and auditory system involvement. The rarity of CPP tumors in CPA along with a variety of presenting symptoms makes the diagnosis of CPPs more challenging while considering this variance could be helpful in prompt diagnosis.


Results
This study included 7 adult patients with CPP in CPA who were treated surgically at our institutions between 2013 and 2017 (Table 1). There were 4 male and 3 female patients, and the mean age was 40.57 years (range 32-47 years). The average follow-up period after surgery was 16.2 months (range 12-24 months). Follow-up was completed in all cases because no evidence of recurrence was observed for 12 months after surgery.
In addition to all related articles, additional cases from their references were reviewed. A total of 17 articles were included in this review.

Literature review
Sixty-eight cases were derived from the literature, either published as a case report or mentioned in a larger case series focusing on a different research question. Of these 68 cases, 15 were younger than 18 are excluded. Therefore, 60 cases (including our 7 cases) are included in this study.

Demographics
The complete series (both our series and the cases identified in the literature) consisted of 37 females and 23 males. Mean age of cases was 40.78 (median: 40), and there was no significant difference between male (average: 40.7; median: 40) and female (average:40.8; median: 39) patients.

Presenting Symptoms
To facilitate the review, the clinical symptoms of patients were divided into 7 categories including symptoms associated with increased intracranial pressure (ICP), cerebellar symptoms, auditory symptoms, symptoms related to the lower motor system, symptoms pertained to the nerve VII involvement, manifestations related to the nerve V involvement, and hemiparesis (Table 2). Patients with CPP in CPA had a wide range of clinical symptoms, most commonly associated with an increase in ICP (in almost all patients), symptoms related to cerebellar damage, auditory damage, nerve VII involvement, and other manifestations, each of which may be seen in other tumors of this area with a different pathology.
As shown in Figure 1, among the most important clinical symptoms mentioned in 60 patients, the highest prevalence of clinical manifestations of CPP in CPA is related to the increased ICP (51 cases, 85%), cerebellar involvement (32 cases, 53.33%), auditory system involvement (23 cases, 38.33%), nerve VII involvement (13 cases, 21.66%), lower motor (14 cases, 23.33%), nerve V involvement (9 cases, 15%), and hemiparesis (5 cases, 8.33%). Furthermore, among all symptoms which mentioned in all reports, symptoms related to 8th, lower motor, 7th, and 5th cranial nerves were the most prevalent symptoms respectively following ICP rising and cerebellar signs ( Figure 2). This frequency is perfectly matched with the anatomical proximity to the Foramen Luschka.

Discussion
Cerebellopontine angle (CPA) is the most common site for posterior fossa tumors, where generally 10% of all brain malignancies occur 2 . The most common tumors of this region include vestibular schwannoma, which accounts for approximately 80% of the CPA tumors 2 . Other common pathologies involved in this area include meningioma, epidermoid tumors, arachnoid cysts, lipoma, and metastases 11 . However, given the high prevalence of schwannoma in this area, the most common manifestations are vertigo, tinnitus, and hearing loss. schwannoma is commonly associated with symptoms of tumor pressure on the surrounding structures such as unilateral hearing loss, tinnitus, and vertigo 40 .
Meningioma is the second common tumor of CPA with similar clinical symptoms such as hearing loss, dizziness, tinnitus, and cerebellar symptoms, but in most cases, meningioma is detected when the tumor is enlarged and compresses nerves V and X, resulting in trigeminal neuralgia, facial numbness, facial paralysis, and swallowing impairment 11,21 .
Epidermoid cysts are the third most common tumors in CPA, accounting for approximately 5% of the tumors in this area 4 . Like vestibular schwannoma and meningioma, the common symptoms of these tumors are cranial nerves involvement, especially trigeminal neuralgia, hemifacial spasm, and signs of compression on the brain stem and the cerebellum 19,28 .
In most cases, metastases may be confused with vestibular schwannoma; however, due to their invasive nature, the occurrence and exacerbation of symptoms of metastatic tumors in CPA are faster than other tumors 1,37 .
Hydrocephalus is, by far, the most common presenting symptom for most patients with CPP 3 . The mechanism of ventricular enlargement is most commonly a  Table2.
Based on the previous reports and reviews, clinical symptoms of all patients were divided into seven categories. Figure 1 Clinical symptoms graph Clinical symptoms pie chart