Department of Gynecology and Obstetrics, Fetomaternal Hospital, Avenida Maritima Del Sur., Gran Canaria, Spain.

Case report

We present an unusual case of a fetus with an intracranial mass located in the lateral cerebral ventricle that was diagnosed by routine obstetric ultrasound at 37th week of pregnancy. Previous ultrasonographic observations were normal. A homogeneous solid mass occupied almost the whole space of the left lateral ventricle. Midline structures of the brain were displaced to the opposite side. The presumptive diagnoses were choroid plexus papilloma versus fetal intracranial hemorrhage. The newborn was delivered by a caesarean section at the 38th week of pregnancy. A neurosurgical operation with the extirpation of the tumor was performed 23 days after delivery. Histological evaluation confirmed the diagnosis of the choroid plexus papilloma. The infant is two years old now and is doing well.

Images 1, 2: 37 weeks of pregnancy; the image 1 shows a coronal gray scale view of the hyperechoic mass located within the left lateral cerebral ventricle representing the choroid plexus papilloma. The image 2 shows a parasagittal color Doppler scan of the left lateral cerebral ventricle showing the hyperechoic choroid plexus papilloma with a rich superficial vascularization.

Videos 1, 2: 37 weeks of pregnancy; the video 1 shows a coronal gray-scale view of the hyperechoic mass located within the left lateral cerebral ventricle representing the choroid plexus papilloma. The video 2 shows a parasagittal color Doppler scan of the left lateral cerebral ventricle showing the hyperechoic choroid plexus papilloma with a rich superficial vascularization.

Prevalence

Papillomas of the choroids plexus account for less than 1% of all intracranial tumors in adults, but most often they occur in children and constitute up to 1.5-15% of childhood intracranial neoplasms [1]. Papillomas are more frequent than carcinomas of the choroid plexus, but the difference between the both is always histological (nuclear hyperchromatism, cellular pleomorphism and mitotic activity) [1-3].

Etiology

Papillomas arise from the single layer of cuboidal epithelial cells lining the papillae of the choroid plexus and a recent study points to the role of a transmembrane receptor protein (Notcp) in the pathogenesis of human choroid plexus tumors [4].

Sonographic findings

An echogenic homogenous mass with surface vascularization and cerebral ventricular enlargement can be observed in the case of choroid plexus papilomas. Anatomical displacement of the midline brain structures due to tumor compression could be also present. The tumor is often accompanied by a hemorrhage.

Differential diagnosis

Teratomas, ventricular hemorrhage and choroids plexus carcinoma should be taken into consideration in the differential diagnostic thoughts.

Associated anomalies

The choroid plexus papilloma is often isolated; however association with the Aicardi syndrome has been described by some authors [5, 6]. 

Prognosis

Choroids plexus papillomas are benign, but occasionally an invasive variant can be found. The malignant evolution to carcinoma may occur in about 10-30% of cases [1, 2]. The prognosis is determined by the completeness of lesion removal at surgery.

Management

Complete surgical resection is the best treatment for choroid plexus papilloma [1-3]. Tumor recurrence after total resection is uncommon.

References

1.  McEvoy AW, Harding BN, Phipps KP, Ellison DW, Elsmore AJ, Thompson D, Harkness W, Hayward RD. Management of choroid plexus tumours in children: 20 years experience at a single neurosurgical centre. Pediatr Neurosurg. 2000 Apr;32(4):192-9.
2.  Pencalet P, Sainte-rose C, Leullouh et al. Papillomas and carcinomas of the choroid plexus in children. J Neurosurg. 1998 Mar;88(3):521-8.
3. Strojan P, Popović M, Surlan K, Jereb B. Choroid plexus tumors: a review of 28-year experience. Neoplasma. 2004;51(4):306-12.
4. Dang L, Fan X, Chaudhry A, Wang M, Gaiano N, Eberhart CG.Notcp signaling initiates choroid plexus tumor formation. Oncogene. 2006 Jan;19;25(3):487-91.
5. Noguchi A, Shiokawa Y, Kobayashi K, Saito I, Tsuchiya K, McMenomey SO, Delashaw JB. Choroid plexus papilloma of the third ventricle in the fetus. Case illustration. J Neurosurg. 2004 Feb;100(2 Suppl Pediatrics):224.
6. Erman T, Göçer AI, ErdoÄŸan S, Tuna M, Ildan F, Zorludemir S. Choroid plexus papilloma of bilateral lateral ventricle. Acta Neurochir (Wien). 2003 Feb;145(2):139-43; discussion 143.