Primary Choroid Plexus Papilloma of the Foramen Magnum

— Case Report—

Hiroaki NOMURA, Fumiyuki MOMMA, Susumu FURUICHI, and Junji OKAMOTO

Department of Neurosurgery, Yao Tokushukai Hospital, Yao, Osaka

Abstract

A 50-year-old male presented with a choroid plexus papilloma in the foramen magnum manifesting as dysesthesia in the right hand and severe headache. Magnetic resonance imaging clearly showed that the tumor was located in the cerebellomedullary cistern, without extension into the fourth ventricle. However, differentiation from hemangioblastoma or foramen magnum tumor was difficult by neuro imaging. Intraoperative observation found the tumor was located extraventricularly and attached to the choroid plexus of the foramen of Magendie. The tumor was grossly totally resected. Histological exami nation proved the tumor was a choroid plexus papilloma without malignancy. His neurological deficits resolved almost completely.

Key words: choroid plexus papilloma, foramen magnum, foramen of Magendie

Introduction touch sensations. His cranial nerves were all intact except for slight deviation of the tongue to the left Choroid plexus papillomas are uncommon benign when protruded. The patient also had bilateral neuroectodermal tumors of the central nervous sys papilledema. Computed tomography revealed a high tem, accounting for 0.5% of all intracranial ne density area with mottled calcification in the cerebel oplasms in adults.') Papillomas in children are lomedullary cistern. There was slight ventricular predominantly located in the lateral ventricle, dilatation indicating obstructive hydrocephalus. whereas in adults the primary site is the fourth ven Magnetic resonance (MR) imaging showed the tricle. Primary extraventricular papillomas are un tumor was isointensity on Ti-weighted images (Fig. common and mostly occur in the cerebellopontine 1 left) and high intensity on T2-weighted images. T1 angle.') We report a rare case of primary choroid weighted images with gadolinium showed a marked plexus papilloma located in the foramen magnum. ly enhanced and well-defined lesion compressing the cerebellum and the medulla oblongata (Fig. 1 cen Case Report ter, right). The tumor was located in the cerebel lomedullary cistern without extension into the A 50-year-old male presented with a 9-month history fourth ventricle. Arteriography demonstrated abnor of progressive numbness in the right hand. The mal vessels at the foramen magnum originating symptoms gradually deteriorated and he also devel from the bilateral vertebral arteries and posterior oped a persistent headache in the occipital area, inferior cerebellar arteries, but no tumor stain was beginning in late July 1993. The headache gradually observed. The preoperative diagnosis was heman increased in severity and he became excessively gioblastoma or a foramen magnum tumor such as excited during a conversation with his wife on Sep meningioma or neurinoma. tember 6, 1993, and was then hospitalized. Median suboccipital craniectomy and C-1 laminec Neurological examination found dysesthesia in tomy exposed the tumor extending into the cisterna the right hand with disturbance of pinprick and magna (Fig. 2). The tumor compressed the tonsil and the medulla oblongata. It was grayish and soft, but

Received September 24, 1996; Accepted May 26 , contained a small calcified area. It also bled very 1997 easily. The main feeding vessel of the tumor came Fig. 1 T,-weighted magnetic resonance (MR) image showing a mass in the cerebellomedullary cistern (left). T,-weighted MR images with gadolinium showing a markedly enhanced ex traventricular mass compressing the cerebellum and the medulla oblongata (center, right).

from the choroid plexus of the fourth ventricle and bilateral draining vessels were present at the lateral medullary cistern. The tumor was attached to the choroid plexus of the foramen of Magendie. The

Fig. 3 Photomicrograph of the resected specimen Fig. 2 Intraoperative photograph showing the showing papillary structures formed by a mass (arrows) located in the cisterna mag single layer of cuboidal or columnar cells on na. M: medulla oblongata, upper: cranial a fine fibrous stroma without evidence of direction, lower: caudal direction. malignancy. HE stain, x 200. fourth ventricle was identified at the upper border of the intervertebral foramen. Therefore, foramen mag the tumor. Gross total resection was achieved. num tumors are usually located at the anterior or an Histological examination found the tumor consist terolateral region to the spinal cord. MR imaging ed of delicate papillary processes formed by a single may reveal differences in location between our case layer of cuboidal or columnar cells lying on a fine fi and the foramen magnum tumors. However, the MR brous stroma (Fig. 3). Some tumor cells had cyto imaging findings in the present case were similar to plasmic positivity for glial fibrillary acidic protein, those of solid hemangioblastoma. The characteristic S-100 protein, and periodic acid-Schiff staining. angiographic finding of the choroid plexus papillo The histological diagnosis was a choroid plexus mas is a finely granular tumor stain,s) whereas that papilloma without evidence of malignancy. of solid hemangioblastomas is homogeneous or mot The patient made an uneventful recovery. The neu tled hypervascularity.') This observation may distin rological deficits resolved except for slight numb guish papillomas from solid hemangioblastomas. ness of the right hand. Postoperative MR imaging 6 However, the preoperative diagnosis in the present months later revealed no evidence of recurrence. case was very difficult.

Discussion References

Choroid plexus papillomas located primarily in the 1) Bohm E, Strang R: Choroid plexus papillomas. J Neu extraventricular region are uncommon. The most rosurg 18: 493-500, 1961 frequent primary extraventricular location is the 2) Greene RC: Extraventricular and intracerebellar cerebellopontine angle, where 21 cases have been papilloma of the choroid plexus. J Neuropathol Exp reported.') Three cases of primary intraparenchymal Neurol 10: 204-207, 1951 3) Kimura M, Takayasu M, Suzuki Y, Negoro M, choroid plexus papilloma have been reported,2,8,1°) Nagasaka T, Nakashima N, Sugita K: Primary two in the cerebellar hemisphere and one in the fron choroid plexus papilloma located in the suprasellar tal lobe, and a rare case of primary choroid plexus region: case report. Neurosurgery 31: 563-566, 1992 papilloma in the suprasellar region.') The MR imag 4) Martin N, Pierot O, Sterkers O, Mompoint D, Nahum ing findings of our case, especially the sagittal view, H: Primary choroid plexus papilloma of the cerebel clearly demonstrated that the tumor had developed lopontine angle: MR imaging. Neuroradiology 31: at an extraventricular site, not in the fourth ventri 541-543,1990 cle. Primary extraventricular development occurs 5) Morello G, Migliavacca F: Primary choroid papillo under two conditions. Cerebellopontine angle papil mas in cerebellopontine angle. J Neurol Neurosurg lomas develop from the normal choroid tuft outside Psychiatry 27: 445-450, 1964 the foramen of Luschka,5) whereas intraparen 6) Raimondi AJ, Gutierrez FA: Diagnosis and surgical treatment of choroid plexus papillomas. Childs Brain chymal or suprasellar papillomas develop from ec 1:81-115,1975 topic remnants of choroid tissue.') The surgical find 7) Reynier Y, Baldini M, Hassoun H, Vigouroux RP, ings suggested that our case had developed from the Paillas JE: Haemangioblastoma of the brain. Comput choroid plexus lying in the foramen of Magendie ed tomography and angiographic studies in 17 and extended to the extraventricular space. A previ patients. Acta Neurochir (Wien) 74: 12-17, 1985 ous case of primary choroid plexus papilloma locat 8) Robinson RG: Two cerebellar tumors with unusual ed in the cerebellomedullary cistern had also appar features. J Neurosurg 12: 183-186, 1955 ently developed from part of the choroid plexus 9) Rovit RL, Schechter MM, Chodroff P: Choroid plexus lying in the foramen of Magendie.11 papillomas: observations on radiographic diagnosis. The differential diagnosis for papilloma includes AJR Am J Roentgenol 110: 608-617, 1970 hemangioblastoma and foramen magnum tumors 10) Skala O: Überein extraventrikuläres Plexuspapillo ma. Zbl Allg Path 95: 183-187, 1956 such as meningioma or neurinoma. Early symptoms 11) van Swieten JC, Thomeer RTWM, Vielvoye GJ, Bots of foramen magnum meningioma and neurinoma in GThAM: Choroid plexus papilloma in the posterior clude neck pain or dysesthesia of the hands, and fossa. Surg Neural 28: 129-134, 1987 hemangioblastoma causes intracranial hypertension and cerebellar ataxia. However, such symptoms are so common that it is impossible to differentiate the tumors. Foramen magnum meningiomas are at Address reprint requests to: H. Nomura, M.D., Department tached to the dura adjacent to the perforation by the of Neurosurgery, Yao Tokushukai Hospital, 3-15-38 vertebral artery, and neurinomas in this region origi Kyuhoji, Yao, Osaka 581, Japan. nated from the C-1 or C-2 root, extending through