case_images: PMC11799679_01
case_images: Left hemifacial hyperpigmentation of the patient with ptosis and proptosis of the left eye, with peripheral type paresis of cranial nerve (CN) VII.
case_images: SNI-16-21-g001.jpg
case_images: PMC11799679_01_SNI-16-21-g001.jpg
case_images: F1
case_images: A dermatological examination revealed a hemifacial nodule with well-defined borders, variegated black-to-greenish pigmentation, and proptosis of the left eye [Figure 1].
case_images: Head computed tomography scan: well-defined, hyperdense lesion with calcification, measuring approximately 1.7 x 1.7 cm, located in the left cerebellopontine angle. An additional larger lesion, measuring 3.8 x 4.3 cm, was observed in the left retrobulbar and temporal region, displacing the left eye globe anteriorly. This lesion also exhibited hyperdensity, measuring approximately 70 Hounsfield units, and contained calcifications.
case_images: SNI-16-21-g002.jpg
case_images: PMC11799679_01_SNI-16-21-g002.jpg
case_images: F2
case_images: A computed tomography scan of the head [Figure 2] revealed two distinct areas of concern.
case_images: (a-c) Axial, coronal, and sagittal section of brain magnetic resonance imaging with contrast: A heterogeneously enhancing mass surrounding the left optic nerve. The lesion, measuring approximately 3.8 x 3.9 x 3.5 cm, exhibited hyperintensity on T1-weighted images and hypointensity on T2-weighted images. Diffusion-weighted imaging demonstrated unrestricted diffusion within the lesion. Notably, the mass displayed a "tram-track sign" and exhibited strong contrast enhancement, suggestive of a nerve sheath origin. This primary lesion extended through the left optic canal into the left cavernous sinus and abutted the left sphenoid convexity, resulting in a proptosis of approximately 2.1 cm. Furthermore, multiple similar lesions were identified, suggestive of meningiomatosis. These included a 0.5 cm lesion in the left frontal convexity, a 0.9 cm lesion in the left lesser sphenoid wing, and a 2 cm lesion in the left cerebellopontine angle.
case_images: SNI-16-21-g003.jpg
case_images: PMC11799679_01_SNI-16-21-g003.jpg
case_images: F3
case_images: The initial conclusion of brain magnetic resonance imaging (MRI) with the contrast of this patient [Figure 3] was a suspected left optic nerve sheath meningioma with the presence of multiple similar lesions raises concern for meningiomatosis in the brain, particularly in the left cerebellopontine angle.
case_images: (a and b) The black-colored dura mater was strikingly found after the removal of the scalp and cranium during the retrosigmoid craniotomy. (c) After the incision of the dura mater, the cerebellum color appears normal.
case_images: SNI-16-21-g004.jpg
case_images: PMC11799679_01_SNI-16-21-g004.jpg
case_images: F4
case_images: After the removal of the cranium, a striking black discoloration of the dura mater was observed, corroborating the suspected melanotic infiltration [Figure 4].
case_images: (a-d) Intraoperative view of black-colored mass in the left cerebellopontine angle compressing the nearby structures, including cranial nerve (CN) V, VII, and VIII.
case_images: SNI-16-21-g005.jpg
case_images: PMC11799679_01_SNI-16-21-g005.jpg
case_images: F5
case_images: The tumor is carefully identified within the left CPA [Figure 5].
case_images: (a-c) Microscopic view of the tumor in x4, x20, and x40 magnification. The stain used is hematoxylin and eosin.
case_images: SNI-16-21-g006.jpg
case_images: PMC11799679_01_SNI-16-21-g006.jpg
case_images: F6
case_images: Histopathological analysis [Figure 6] demonstrated a dense cellular proliferation of malignant tumor cells arranged in nests and sheets.