[A Case of Mature Teratoma in the Third Ventricle with Holmes Tremor].

Intracranial teratoma is a rare disease that frequently occurs in children and young adults. It comprises of approximately 0.1% of the brain tumors. We report a case of a large mature teratoma in the third ventricle with Holmes tremor. A 5-year-old boy presented with tremors 2 years ago. CT showed a 56×48 mm tumor in the third ventricle and hydrocephalus. The tumor was well demarcated from the surrounding brain tissue and contained calcification. MRI indicated a partially high-intensity signal on T1-weighted and T2-weighted images. The preoperative diagnosis was teratoma. Initially, the tumor was biopsied using neuroendoscopy and the Ommaya reservoir was set. The pathological results showed fat-like tissues and fibroblasts. Subsequently, the tumor was completely removed using the interhemispheric transcallosal transchoroidal approach. The tumor included fat and hair tissues. It also included calcification similar to that observed in a tooth. It was strongly adhered near the pineal gland. Pathologically, the diagnosis was a mature teratoma. Postoperatively, the tremor disappeared and the patient was discharged from the hospital without neurological deficits. We believe that compression of the Guillain-Mollaret triangle was relieved by removal of the tumor. Hence, the tremor disappeared after the operation.

Utility of Schwann/2E and Sox10 in distinguishing CD57-negative olfactory groove schwannoma from olfactory ensheathing cell tumor: A case report and review of the literature.

We herein report a patient who was diagnosed as having olfactory groove schwannoma (OGS) which was negative for CD57 (Leu7) but positive for Schwann/2E and Sox10. A 13-year-old female with a chief complaint of headache was referred to our department due to a tumor lesion in the anterior skull base identified by magnetic resonance imaging (MRI). At the first visit, she did not exhibit altered consciousness, motor palsy, anosmia, seizures, or café au lait spots. On contrast-enhanced computed tomography (CT), a heterogeneously enhanced tumor, 50 × 45 × 50 mm in size, was observed at the anterior skull base. The left cribriform plate was thinner on bone window CT. The tumor exhibited strong, heterogeneous gadolinium enhancement on MRI as well. Slight tumor staining was observed by angiography of the left internal carotid artery but not the left external carotid artery. The patient was preoperatively diagnosed as having meningioma and underwent gross tumor resection via the basal interhemispheric approach. The tumor was strongly positive for S-100 protein and negative for epithelial membrane antigen and CD57 by immunostaining. The tumor was positive for both Schwann/2E and Sox10, which aided in the differential diagnosis between OGSs and olfactory ensheathing cell (OEC) tumors, and the definitive diagnosis was OGS. The assessment of immunoreactivities for Schwann/2E and Sox10 might be necessary to differentiate CD57-negative Schwannomas from OEC tumors.

Three-Dimensional Printed Model for Surgical Simulation of Combined Transpetrosal Approach.

BACKGROUND: The combined transpetrosal approach is a complicated skull base surgery with a high degree of difficulty. Herein, we made a 3-dimensional (3D) printed petrous bone with color-coded anatomic sites and evaluated its usefulness as a model to practice drilling associated with combined transpetrosal surgery. METHODS: To design a 3D model of the petrous bone, we chose a representative epidermoid petroclival tumor case who underwent combined transpetrosal surgery at our hospital. A 3D image of the petrous bone embedded with color-coded anatomic sites, including cranial nerves, brainstem, and internal carotid and vertebrobasilar arteries, was created based on preoperative computed tomography scan, magnetic resonance, and digital subtraction angiography images and was then 3D printed. Thirteen neurosurgeons from our department evaluated the anatomic reproducibility and estimated distance between each anatomic site of the 3D image and model and the usefulness of the model for drilling practice. RESULTS: The anatomic reproducibility of both the 3D image and model was high, and the 3D model was considered good for drilling practice (P < 0.05). The error in the estimated distance between anatomic sites in the 3D model was significantly smaller than that of the 3D image (P < 0.0001). CONCLUSIONS: These results indicate that our 3D printed model is very useful for practice with craniotomy and petrosectomy drilling, necessary in the combined transpetrosal approach.

Horizontal pollen transmission of Gentian ovary ring-spot virus is initiated during penetration of the stigma and style by infected pollen tubes.

Gentian ovary ring-spot virus (GORV) infected gentian plants by pollination with GORV-infected gentian pollen grains, but the virus was not horizontally transmitted to gentian plants by transfer of pollen from GORV-infected Nicotiana benthamiana plants. However, N. benthamiana plants were infected with the virus by pollination with infected gentian pollen as well as by pollination with infected N. benthamiana pollen. When infected gentian pollen grains were placed on N. benthamiana stigmas, germinating pollen tubes penetrated into the stigmas and the styles (stigma-style). Virus infection occurred during penetration of the stigma-style, and the virus subsequently spread systemically to the mother plant. On the other hand, most infected N. benthamiana pollen grains failed to germinate on gentian stigmas, and virus infections were not detected in the stigma-style.

A neurosurgical simulation of skull base tumors using a 3D printed rapid prototyping model containing mesh structures.

BACKGROUND: Deep regions are not visible in three-dimensional (3D) printed rapid prototyping (RP) models prepared from opaque materials, which is not the case with translucent images. The objectives of this study were to develop an RP model in which a skull base tumor was simulated using mesh, and to investigate its usefulness for surgical simulations by evaluating the visibility of its deep regions. METHODS: A 3D printer that employs binder jetting and is mainly used to prepare plaster models was used. RP models containing a solid tumor, no tumor, and a mesh tumor were prepared based on computed tomography, magnetic resonance imaging, and angiographic data for four cases of petroclival tumor. Twelve neurosurgeons graded the three types of RP model into the following four categories: 'clearly visible,' 'visible,' 'difficult to see,' and 'invisible,' based on the visibility of the internal carotid artery, basilar artery, and brain stem through a craniotomy performed via the combined transpetrosal approach. In addition, the 3D positional relationships between these structures and the tumor were assessed. RESULTS: The internal carotid artery, basilar artery, and brain stem and the positional relationships of these structures with the tumor were significantly more visible in the RP models with mesh tumors than in the RP models with solid or no tumors. CONCLUSIONS: The deep regions of PR models containing mesh skull base tumors were easy to visualize. This 3D printing-based method might be applicable to various surgical simulations.