Hiroaki Shigeta

Safe and minimally invasive laminoplastic laminotomy using an ultrasonic bone curette for spinal surgery: technical note

BACKGROUND Ultrasonic surgical aspirators have been used mainly for removing brain tumors. Because of their longitudinal and torsional tip, they are used for cutting the bone structures in spinal surgery installing a scalpel-type tip. The purpose of this report is to describe the effectiveness and surgical pitfalls of an ultrasonic bone curette in laminoplastic laminotomy and hemilaminotomy. METHODS We present 12 patients who underwent laminoplastic laminotomy and hemilaminotomy. We used a SONOPET UST-2001 ultrasonic bone curette with HB-05S handpieces (M and M Co, Ltd, Tokyo, Japan). After a tumor was removed, titanium plates were used for the laminoplastic laminotomy and hemilaminotomy. The technical advantage of an ultrasonic bone curette and procedure-related complication were examined. RESULTS There were no major procedure-related complications such as cord injury. Wound infection and subcutaneous fluid collection caused by cerebrospinal fluid leakage did not occur for reconstruction of posterior bony structure. In 1 patient with calcified dura mater associated with tumor, dural tear occurred. The width of the tip was narrow enough for resected laminae to be fused postoperatively, and spinal instability did not occur in all cases. CONCLUSION The scalpel-type ultrasonic bone curette is useful for cutting bone and effective for reconstruction of the laminae. Laminotomy with an ultrasonic bone curette is safe and minimally invasive. To prevent dural tear, we recommend drilling laminae to make the bone thin as the first step, followed by cutting the remaining laminae using a bone curette especially in cases with calcified or tense dura mater.

Coupling of central venous pressure and intracranial pressure in a 6-year-old patient with fontan circulation and intracranial hemorrhage.

A sharp rise in intracranial pressure (ICP) was noted in a 6-year-old girl with Fontan circulation after surgical removal of a hematoma associated with intracranial hemorrhage. Inhalation of nitric oxide resulted in reduction of central venous pressure (CVP) and precipitous fall in ICP, which was otherwise resistant to conventional therapy. Specifically, the rate of fall of ICP (9 mm Hg) exceeded that of the CVP (3 mm Hg), indicating disproportionate CVP-ICP coupling. The present case provides not only a novel insight into cardio-cerebral interaction in Fontan physiology but also useful information regarding the treatment of Fontan patients in the setting of increased ICP.

Serial MR and CT features of primary germinoma originating in the basal ganglia

Serial changes of neuroradiological findings in a 10-year-old boy with primary germinoma originating in the basal ganglia are reported. He presented with a one year history of slowly progressive right hemiparesis. Although initial computed tomography (CT) scans showed no prominent abnormalities, a slight high-density area in the basal ganglia became conspicuous with cortical atrophy on follow-up scans. Sequential magnetic resonance images showed a homogeneous lesion with clear margin and remarkable postcontrast enhancement. Two cell pattern germinoma was histologically verified by CT guided stereotactic biopsy. Following irradiation, the tumour completely disappeared, however, the atrophy of the cerebral hemisphere and the brain stem progressed, and mild hemiparesis remained. We discuss the neuroradiological features and clinical manifestations of this disease.

Temozolomide Treatment for Pediatric Refractory Anaplastic Ependymoma with Low MGMT Protein Expression.

The benefit of postoperative chemotherapy for anaplastic ependymoma remains unknown. We report two pediatric patients with refractory anaplastic ependymoma treated with temozolomide (TMZ). We did not detect O6‐methylguanine‐DNA methyltransferase (MGMT) promoter methylation in tumor samples; however, MGMT protein expression was low. With TMZ treatment, one patient had a 7‐month complete remission; the other, stable disease for 15 months. Three other patients did not respond to TMZ; two had high and one low MGMT expression, and two showed no MGMT promoter methylation. These findings suggest that TMZ may be effective for pediatric refractory anaplastic ependymoma with low MGMT protein expression. Pediatr Blood Cancer

Radiation necrosis following proton therapy successfully treated by low-dose bevacizumab in a patient with relapsed anaplastic ependymoma

To the Editor: After reading with great interest the report by Pillay Smiley et al.1 describing an infant case of brain radiation necrosis (RN) successfully treated by bevacizumab, we herein present a case that further supports the use of the drug for RN in pediatric patients. A 5-year-old male with anaplastic ependymoma experienced a disease relapse 3 years after diagnosis despite initial total gross resection and intensive chemotherapy, and began suffering multiple distant intracranial recurrences. Although all relapsed lesions were well managed by stereotactic radiosurgery, magnetic resonance imaging (MRI) taken 17 months after the disease relapse identified a mass with a maximum diameter of 30 mm in the right lateral ventricle (Figure 1A). We selected proton beam therapy (PBT) at 59.4 Gy (27 fractions) for the tumor due to its size. PBT was well tolerated and no acute major adverse events were observed. Two months after PBT, the patient presented with left visual field loss, headache, and vomiting. He was diagnosed as having brain RN based on the MRI findings of an enhanced mass at the PBT site and circumferential swelling (Figure 1B).2 Since severe surgical adverse effects were expected based on the lesions location, he began treatment with dexamethasone (0.5 mg/day). Following transient improvement of the symptoms, he later presented with generalized convulsions, decreased consciousness, headache, nausea, and left visual field loss 1 month after RN onset. Enhanced brain MRI showed progressed RN with complicating cerebral edema (Figure 1C). Although his

Multinucleated giant cells in Langerhans cell histiocytosis

A 5-year-old boy was admitted to our hospital with a tender bulging lump on his forehead. Gadolinium-enhanced T1-weighted magnetic resonance imaging showed a subcutaneous mass destroying the frontal bone (top left). His blood tests were normal. The tumour was completely surgically removed. Histological examination showed multinucleated giant cells (MGCs) and cells with bean-shaped nuclei and pink granular cytoplasm (top right). Immunohistochemistry showed CD1a (bottom left), S100 and langerin (CD207) positivity in most cells, but not in the MGCs. An isolated lytic lesion of Langerhans cell histiocytosis (LCH) was diagnosed. Furthermore, MGCs were positive for CD68 (broad specificity antibody, bottom right), which suggested that an increase in osteoclasts accompanied the LCH. There has been no relapse after surgery despite no further treatment. LCH is a rare disease caused by the clonal accumulation and infiltration by Langerhans cells, along with lymphocytes, macrophages and eosinophils. This disease occurs as single or multiple lesions in the bones, skin, lymph nodes or lungs, but most cases involve the bones. In these patients, osteoclasts play a major role in bone destruction. A differential diagnosis of LCH should be considered for bone tumours, including giant cell tumours, when many osteoclasts are present.