[A Surgical Case of Anaplastic Ependymoma Involving a Bridging Vein that Drained Directly into the Occipital Sinus].

INTRODUCTION: The draining veins of the brain stem and cerebellum commonly drain into the petrosal vein and sigmoid sinus, and often drain into the marginal sinus in the caudal part of the posterior fossa. Here, we report a rare case of anaplastic ependymoma involving a bridging vein that drained directly into the occipital sinus. CASE DESCRIPTION: A 6-year-old boy was admitted to our hospital with a 1-month history of nausea, headache, and dizziness. Magnetic resonance imaging(MRI)revealed a markedly enhanced fourth ventricular tumor and obstructive hydrocephalus. Surgical removal was performed via a midline suboccipital approach. When opening the dura, we observed a bridging vein that directly connected the brain stem and the tumor with the occipital sinus. Therefore, the Y-shaped dura mater incision was not inverted, and the tumor was totally removed while preserving the draining vein. After the operation, the patient's clinical course was uneventful. The pathological diagnosis was anaplastic ependymoma(WHO grade III). Subsequently, the patient received radiotherapy and was discharged without any neurological deficits 9 weeks after the operation. At 10 months after the initial surgery, the tumor recurred on the fourth ventricle floor. Thus, we performed a second surgical procedure and noted that the bridging vein had regressed. CONCLUSION: We report a rare draining vein that directly connected the brain stem to the occipital sinus. The tumor was removed without sacrificing this vein. Since the draining system of the posterior fossa is sometimes very complicated, we need to pay attention to it during the pre- and intra-operative periods.

[A Case of Lymphocytic Adenohypophysitis Presenting Visual Disturbance in the Third Trimester of Pregnancy].

Lymphocytic hypophysitis(LH)has first been described as an autoimmune endocrinopathy by Goudie in 1962. In particular, lymphocytic adenohypophysitis(LAH)is usually associated with pregnancy and hypopituitarism due to insufficient endocrine of ACTH. However, several cases of LAH in pregnant patients showing only visual disturbances have recently been documented. We treated a patient with LAH presenting only the chiasma syndrome in the third trimester without hypopituitarism. A 27-year-old woman unexpectedly experienced visual disturbance starting in the 28th week of pregnancy. Her symptoms progressed rapidly. MRI revealed a pituitary mass lesion compressing the optic chiasma. In addition, ophthalmological examination revealed bitemporal hemianopsia. The patient underwent endoscopic transsphenoidal surgery(eTSS)during the 30th week of pregnancy. LH was diagnosed histologically during surgery. We performed decompression of optic chiasma. After surgery, the patient's visual field markedly widened and the pituitary mass regressed along with replacement of corticosteroids. In the 37th week of pregnancy, she delivered a healthy baby. We speculate that the reason for the absence of hypopituitarism during pregnancy in patients with LH, especially in the third trimester, might be that the placental endocrine system masks pituitary endocrinopathy. In summary, we report a case of LAH that did not present with hypopituitarism, and eTSS could be performed safely during pregnancy.