Brainstem intraparenchymal schwannoma: A case report and literature review

Abstract

Background: Intracranial intraparenchymal schwannomas (IS) are rare tumors that have mainly been described in case reports. Here, we report on a case of a brainstem IS and included a comprehensive literature review. Case Description: A 74-year-old man presented with progressive gait disturbances. CT- and MRI-imaging revealed a contrast-enhancing mass accompanied by a cyst in the dorsolateral pons. Hemangioblastoma was suspected and surgery was advised. During surgery, gross total resection of a non-invasive tumor was performed. Postoperative recovery was uneventful. Based on histopathological examination, the intraparenchymal brainstem tumor was diagnosed as schwannoma. Conclusion: Our extensive review illustrates that ISs are benign tumors that most often present in relatively young patients. Malignant cases have been described but form an extremely rare entity. Preoperative diagnosis based on radiological features is difficult but should be considered when peritumoral edema, calcifications, and cysts are noted. In benign cases, gross total resection of the lesion is curative. To adequately select this treatment and adjust the surgical strategy accordingly, it is important to include IS in the preoperative differential diagnosis when the abovementioned radiological features are present.

A rapidly growing intraparenchymal schwannoma in a geriatric patient: a case report and literature review

“…MINST is extremely rare, only one case was reported in the age group above 60 years [8]. The malignancy rate was approximately 5% in the age group above 60 years, which was slightly lower compared to other age groups [4].…”

“…Of these, 12.0% (18) of patients were over 60 years of age, which is unexpected. The incidence was higher in men in the age group under 30 years (male:female; 1.84:1); whereas, the pattern was reversed in the group above 60 years of age (male: female; 0.46:1) (Table 1) [4][5][6][7][8]. IS may originate anywhere in the intracranial region; however, appears to be more frequent in the supratentorial region during young age, whereas it is commonly located in the infratentorial region in individuals > 60 years of age [4].…”

“…The incidence was higher in men in the age group under 30 years (male:female; 1.84:1); whereas, the pattern was reversed in the group above 60 years of age (male: female; 0.46:1) (Table 1) [4][5][6][7][8]. IS may originate anywhere in the intracranial region; however, appears to be more frequent in the supratentorial region during young age, whereas it is commonly located in the infratentorial region in individuals > 60 years of age [4]. Although the pathophysiology of IS has not yet been clearly identified, 2 hypotheses have been proposed: (1) developmental theory, (2) non-developmental theory.…”

“…The diagnosis of intraparenchymal schwannoma by imaging is challenging, and is dependent on histopathological analysis and immunohistochemical findings. The histopathological appearance was characterized by Antoni A and B cells, while immunohistochemical staining showed positive expression of S-100 whereas epithelial membrane antigen and GFAP were absent in most cases [4,7].…”

Intraparenchymal Schwannoma of Temporal Lobe: A Case Report and Review of the Literature

“…11 Reviewing the literature showed that the frontal and temporal lobes are the most common sites for developing IS. 8 There are no specific radiological features for the IS, and imaging findings are thought to be similar to the ISs. These features include calcification, cystic components, and edema.…”