Subarachnoid hemorrhage caused by an undifferentiated sarcoma of the sellar region

Abstract

Background: It is rare for patients with pituitary apoplexy to exhibit concomitant subarachnoid hemorrhage (SAH). Only a handful of patients with pituitary apoplexy have developed such hemorrhagic complications, and histopathological examination revealed pituitary adenoma as the cause of SAH.

Case report: A previously healthy 35-year-old woman was brought to our institution after complaining of severe headache and left monocular blindness. Brain computed tomography showed a diffuse SAH with a central low density. Subsequently, the brain magnetic resonance imaging revealed an intrasellar mass with heterogeneous contrast enhancement. The patient was presumptively diagnosed with SAH secondary to hemorrhagic pituitary adenoma and underwent transcranial surgery to remove both the tumor and subarachnoid clot. A histological evaluation of the surgical specimen revealed malignant cells with strong predilection for vascular invasion. Following immunohistochemical evaluation, the tumor was negative for the majority of tumor markers and was positive only for vimentin and p53; thus, a diagnosis of undifferentiated sarcoma was established.

Conclusions: This case was informative in the respect that tumors other than pituitary adenoma should be included in the differential diagnosis of patients with pituitary apoplexy.

Keywords: Pituitary apoplexy; sella turcica; subarachnoid hemorrhage; undifferentiated sarcoma.

Figure 1

Computed tomography of the brain showing subarachnoid chemorrhage with a central low density (a). No substantial sellar enlargement is observed with a sagittal reconstructed view (b). Brain computed tomography angiography showing the absence of a ruptured aneurysm (c). Computed tomography obtained 7 days postoperatively showing extensive cerebral infarction due to vasospasm (d)

Figure 2

Magnetic resonance imaging showing an intrasellar mass which is depicted as low-intensity on a nonenhanced T1-weighted image (a). With gadolinium, the mass exhibits strong enhancement (b, sagittal view; c, axial view). On a T2-weighted image, the mass is depicted as heterogeneous high intensity, and a dense subarachnoid clot was also observed in the prepontine cistern (d)

Figure 3

On H and E staining, the tumor cells are seen to have proliferated densely, either in a medullary or trabecular pattern, and densely arranged tumor cells with large, irregular nuclei and many mitotic figures are observed (a). In another area, tumor invasion to the venous wall is observed (b). Although an extensive immunohistochemical study was performed to identify the histological origin of the tumor, it is positive only for vimentin (c) and p53. The MIB-1 labeling index is 63.6%, indicating potent proliferative activity of the tumor (d)