Surgical management of choroid plexus papilloma of the cerebellopontine and cerebellomedullary angle: classification and strategy

Abstract

Choroid plexus papillomas (CPPs) are primary neuroectodermal neoplasms that usually arise in the fourth ventricle in adults. In this study, we present 12 patients with CPP arising from the cerebellopontine angle (CPP-CPA) and/or of the cerebellomedullary angle (CPP-CMA) that were treated in our department. Patients who underwent surgery for the treatment for CPP-CPA/CMA from January 2004 to March 2020 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. CPPs were classified according to their location into type 1 (tumor portion only in the CPA,), type 2 (tumor portions only in the CMA), and type 3 (tumor portions both in the CPA and CMA). Patients were evaluated for initial symptoms, previous therapies in other hospitals, extent of tumor resection, recurrence rate, and complications by reviewing patient documents. Of approximately 1500 CPA lesions, which were surgically treated in our department in the last 16 years, 12 patients (mean age 42 ± 19 years) were found to have CPP-CPA/CMA. Five were male, and seven were female patients. Gross total resection was achieved in nine cases, and a subtotal resection was attained in three cases. Tumor recurrence in the same location after the first surgery in our hospital was observed in 2 patients after 15 and 40 months of follow-up, and in another patient, distant metastases (C3/4 and L3 levels) were observed. Surgical removal of CPP is the treatment of choice, but additional therapeutic options may be necessary in case of remnant tumor portions, recurrence, or malignant transformation.

Keywords: Bochdalek’s flower baskets; CPA; Cerebellopontine angle; Choroid plexus papilloma; Ectopic choroid tissue; Facial nerve.

Fig. 1

Coronal (A) and axial (B + C) MRI of type 1 choroid plexus papilloma: tumor portions are present in the cerebellopontine angle, without any tumor portions in the cerebellomedullary angle (superior to the line between the pons and medullar oblongata) (this patient had also drop metastases in the contralateral cerebellopontine angle)

Fig. 2

Axial MRI (A, B, C, D) of different Type 2 choroid plexus papillomas: tumor portions are present in the cerebellomedullary angle (inferior to the line between the pons and medullar oblongata), without any tumor portions in the cerebellopontine angle

Fig. 3

Coronal (A) and axial (B + C) MRI of type 3 choroid plexus papilloma: tumor portions are present in the cerebellopontine angle (CPA) and cerebellomedullary angle (CMA) (tumor portions superior and inferior to the line between the pons and medullar oblongata); angiography (D) revealed that the blood supply to the tumor arose from the right anterior inferior cerebellar artery and right posterior inferior cerebellar artery

Fig. 4

A Well-differentiated papillary pattern composed of a monolayer of monomorphic round cells (HE × 400); B clear membranous staining for Kir7.1 (× 200)

Fig. 5

Removal of a type 1 choroid plexus papilloma: A opening of the internal auditory canal, B debulking of the tumor (using an ultrasonic aspirator), C the tumor is dissected from surrounding structures, D gross total resection was achieved