In literature review, only two descriptions about meningiomas induced by both radiotherapy and a silicone drain were found. This has made our description the third such case report in available literature (Table 1).
Table 1
Summary of patients with meningiomas induced by radiotherapy and a silicone drains cases
study
|
patient age
|
gender
|
tumor grading
|
tumor location
|
time perioda
|
outcome
|
Saleh et al. (1991)
|
48
|
male
|
WHO I
|
parietal
|
30
|
favorable
|
Holthouse et al. (1999)
|
25
|
male
|
WHO I
|
parietal
|
20(10)b
|
favorable
|
Our (2020)
|
30
|
male
|
WHO I
|
frontal
|
15
|
favorable
|
a time period from radiotherapy and shunt implantation to meningioma diagnosis |
b 10 years before the diagnosis of meningioma and 10 years after radiotherapy and first shunt implantation, the patient had drain replaced |
First such case was described by Saleh et al. (1991) and the second by Holthouse et al. (1999) [4, 7]. Our patient was treated in 2010, but his case was described in 2020, as a summary of the 10-year follow-up.
Saleh et al. described 48-year-old man with parietal meningioma developed around the intraventricular drain. 30 years earlier he had undergone surgery and 5000 cGy radiotherapy due to pineal tumor and shunt implantation due to hydrocephalus [7]. In description of Saleh tumor was centered around the drain. Meningioma was removed by craniotomy without complications. Shunt and drain were also removed with the tumor. Histopathological examination revealed fibroblastic meningioma without atypical features [7].
Holthouse et al. described 25-year-old man with parietal meningioma also developed around the intraventricular drain. This patient was treated surgically 20 year earlier due to mixed cerebellar glioma, which was followed by seven cycles of radiotherapy and shunt implantation due to hydrocephalus [4]. 10 years before the diagnosis of meningioma, the patient had drain replaced due to shunt dysfunction and no meningioma was found that time. The tumor was removed by totally. During the procedure, the intraventricular valve drain was left in place, as it was patent and functional and was attached with adhesions of the choroid plexus [4]. Histopathological examination revealed meningothelial meningioma cells separated by layers of collagen [4].
Based on the references, both Saleh and Holthouse emphasized that the mechanism of such meningiomas development was oncogenesis on the basis of a chronic inflammatory reaction [4, 7]. It has been noted that neoplasms secondary to radiation are more common in chronically inflamed tissues [2, 4]. A similar example has been meningiomas developed in connection with bone prosthesis in patients after cranioplasty [4].
Meningiomas induced by radiotherapy and a silicone foreign body are extremely rare. For last 30 years, only 3 such cases have been reported, including ours in the available literature.
All described cases of such meningiomas presented low malignancy and good prognosis. Our case, however casuistic, can be significant advice for oncological patients with shunts systems who had undergone brain radiotherapy.