Atypical primary meningioma in the nasal septum with malignant transformation and distant metastasis

Abstract

Background: Primary extracranial meningiomas (PEMs) originating from the nasal septum are extremely rare, as are extracranial metastases of meningiomas.

Case presentation: A 44-year-old male presented with a 2-month history of left-side nasal obstruction and frequent episodes of epistaxis. A friable mass originating from the nasal septum was resected completely via an endoscopic endonasal approach. According to WHO criteria, the tumor was diagnosed as an atypical meningioma radiologically and histopathologically. Two years later, a tumor recurred at the primary site with the same histopathological findings, and the patient was given local external radiotherapy (6840 cGy in 38 fractions). Two months after this local recurrence, a left anterior chest wall mass and a left parietal area scalp mass were observed. The subcutaneous mass was resected and showed histological evidence of malignant transformation. Several months after the last operation, the patient died.

Conclusions: We describe the clinical, radiological, and bio-pathological features of this unique case and review the literature on atypical PEMs originating in the nasal septum. To our knowledge, this is the first reported case of an atypical PEM originating from the nasal septum that recurred with malignant transformation and extracranial metastasis.

Figure 1

Computed tomographic images before surgery. (A) Non-contrast-enhanced PNS CT scan showing the primary lesion in the left nasal cavity. (B) The lesion showed heterogeneous enhancement on contrast-enhanced CT images.

Figure 2

Magnetic resonance images before surgery. (A) T1-weighted PNS MRI showed a primary lesion of slightly lower signal intensity in the left nasal cavity. (B) The lesion was heterogeneously isointense on T2-weighted images. (C) Contrast-enhanced MRI showed heterogeneous enhancement of the lesion. (D) Coronal reconstruction of a T1-weighted MRI scan revealed an isolated primary lesion with no evidence of direct attachment to brain tissue.

Figure 3

Histopathology of the primary tumour. (A) Uniform cells with a sheet-like or vague parallel fascicle-like growth involving the nasal septum (×100, H&E). (B) Atypical cells having round-to-oval nuclei, with prominent nucleoli and occasional mitoses (×400, H&E). The tumour cells were diffusely positive for EMA (C, ×400) and vimentin (D, ×400).

Figure 4

Histopathology of the recurred and metastatic tumours. (A) Atypical cells having round-to-oval nuclei, with prominent nucleoli and frequent mitoses in the nasal cavity recurring tumour. (B) The metastatic tumour had a higher mitotic index (up to 40 mitoses within 10 HPF) and Ki-67 labeling index (40%) than the primary tumour (×400, H&E). (C) Geographic tumoural necrosis and hemorrhage (×400, H&E).