Hidekazu Masaki

Syndromes Associated with Vascular Tumors and Malformations: A Pictorial Review

Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system has been strongly recommended in recent years because of the need for separate therapeutic measures for patients with vascular tumors and malformations. In the ISSVA classification system, vascular tumors, which are neoplastic, are distinguished from vascular malformations, which are caused by vascular structural anomalies and are not neoplastic, on the basis of the presence or absence of neoplastic proliferation of vascular endothelial cells. It is important that radiologists be familiar with the development, diagnosis, and treatment of vascular tumors and malformations, especially the imaging features of low- and high-flow vascular malformations. Some vascular tumors and malformations develop in isolation, whereas others develop within the phenotype of a syndrome. Syndromes that are associated with vascular tumors include PHACE syndrome. Syndromes that are associated with vascular malformations include Sturge-Weber, Klippel-Trénaunay, Proteus, blue rubber bleb nevus, Maffucci, and Gorham-Stout syndromes, all of which demonstrate low flow, and Rendu-Osler-Weber, Cobb, Wyburn-Mason, and Parkes Weber syndromes, all of which demonstrate high flow. Because imaging findings may help identify such syndromes as systemic, it is important that radiologists familiarize themselves with these conditions.

Radical excision of primary tumor and lymph nodes in advanced neuroblastoma: combination with intensive induction chemotherapy

The role of surgery in the management of children with advanced neuroblastoma is still unclear; no radical surgical technique for resection of primary tumor and lymph nodes has been established. A radical procedure was developed and has been employed in 13 patients over 1 year of age with stage III or IV disease since 1985, together with intensive induction chemotherapy. For abdominal neuroblastoma, the area of retroperitoneal lymph node dissection was divided into six sections: to the left of the abdominal aorta, between the aorta and vena cava, and to the right of the vena cava, with further subdivision according to the level of the renal vein. After excision of the primary tumor, lymph node dissection was carried out systematically in all six sections; gross complete resection was possible in 12 of the 13 patients. All 12 patients attained complete remission at least once in the course of treatment, and 7 underwent autologous bone marrow transplantation. It is noteworthy that local control of the disease was satisfactory in all but 1 patient who had extensive involvement of both renal hila and showed recurrence in the remaining kidney. Eight patients are alive with an average follow-up of 44 months; 7 of them show no signs of disease. After reviewing the results of our previous series and this series, it was concluded that advances in operative techniques and the introduction of intensive induction chemotherapy did increase surgical resectability, the rate of complete remission, and the number of candidates for bone marrow transplantation. Improvement of survival in patients with advanced neuroblastoma may thus be expected.

Prognostic significance of circulating tumor cells and bone marrow micrometastasis in advanced neuroblastoma

PURPOSE The aim of this study was to study the prognostic significance of circulating tumor cells (CTC) and the appropriate indications for aggressive surgery in advanced neuroblastoma. MATERIALS AND METHODS Micrometastasis was sequentially explored using our reverse transcriptase-polymerase chain reaction method in 29 neuroblastoma patients (International Neuroblastoma Staging System stage 4, n = 24; stage 3, n = 5) who treated at our department with the united chemotherapeutic regimen since 1991. Their medical records and detection of CTC and/or the bone marrow micrometastasis were retrospectively reviewed then analyzed statistically. RESULTS The overall survival rate was 58.6% (17/29). Circulating tumor cells were detected in 55.6% of the stage 4 patients, and all deaths were related to systemic metastases in the CTC-positive patients. The detection of CTC scarcely associated with MYCN amplification. In the patients showing MYCN amplification but no CTC, all deaths were related to local relapse or chemotherapy-associated complications. The survival rate was not significantly different between the patients with and without MYCN amplification (56.8% vs 52.7%). However, it was significantly lower in the patients with CTC and/or persistent bone marrow micrometastasis compared to those without detectable micrometastasis (33.8% vs 87.5%; P < .05). CONCLUSIONS The presence of CTC and/or persistent micrometastasis may indicate a significantly high risk, regardless of MYCN amplification. Patients with MYCN amplification but no micrometastasis would be most benefited by highly intensive surgery.

Vein of Galen Aneurysmal Malformation Associated With an Endoglin Gene Mutation

A child with vein of Galen aneurysmal malformation (VGAM) presented with cardiac failure in the neonatal period. The family history revealed his mother to have hereditary hemorrhagic telangiectasia. The child underwent an endoglin genetic analysis after the newborn period, which eventually demonstrated an endoglin mutation. The pathogenesis of VGAM is currently unknown. The findings of this case suggest that an endoglin mutation might be linked with VGAM.

Recanalization of post-transplant late-onset long segmental portal vein thrombosis with bidirectional transhepatic and transmesenteric approach

PV complications are the most frequent vascular complications in pediatric LT. We have experienced a case with chronic postoperative PVT that necessitates combined transhepatic and transmesenteric approach and have confirmed mid‐term patency. An eight‐yr‐old boy had successful LDLT with a left lateral segment graft at the age of two months for HBV‐related acute liver failure. Seven years after transplantation, the patient suddenly showed a melena with hypovolemic shock. Doppler ultrasound and CT revealed intrahepatic bile duct dilatation and main PVT with collateral formation at hepatic hilus and mesenterium of the Roux‐en‐Y jejunal loop. Urgent splenic artery embolization was performed to control the bleeding and was temporarily effective. Therefore, recanalization of PVO was attempted. Because of long segmental PVO and steep angle between the intrahepatic PV and the portal trunk, bidirectional transhepatic and transmesenteric approach was selected and resulted in deploying three metallic stents necessitating additional infusion thrombolytic therapy. The patient is now followed as an outpatient with patent stents for two yr since the procedure. For the rescue of these patients, recanalization of obstructed PV trunk with bidirectional approach would be feasible with better graft survival and less invasiveness than conventional surgical interventions.

Spontaneous perforation of choledochal cyst: a case with unusual distribution of fluid in the retroperitoneal space

Images of perforated choledochal cysts typically show an intraperitoneal fluid collection. We report a case with, in addition to free intraperitoneal fluid, fluid collection in the right-side anterior pararenal and perirenal spaces. Surgery confirmed the presence of a perforation at the junction of the cystic duct and the common bile duct. This perforation may explain the biliary leakage extending into the free peritoneal space as well as into the anterior pararenal space and the hepatoduodenal ligament. Anterior pararenal and perirenal spaces communicate with the infrarenal space, and this may result in extension of the fluid into the perirenal space from the anterior pararenal space.

Tumor cell Dynamics and Metastasis in Advanced Neuroblastoma

This study deals with the advancement process of neuroblastoma through clinical observations and circulating tumor cell exploration. Clinical feature, tumor biology, and circulating tumor cell detected by the previously described polymerase chain reaction(PCR) method were analyzed in 31 patients with advanced neuroblastoma treated in our department since 1991 through 2004. Treatment was completed in 28 patients, of whom 17 are alive without the disease and 11 died. The primary lesion was not confirmed in 2 patients with disseminated metastasis, both of whom showed positive circulating tumor cell. Circulating tumor cell was positive in 6 of 9 examined at their first appearance at the hospital, all had stage 4 disease, and 4 of the 6 (66.7%) died of systemic spread of the disease. N-myc was amplified in 15 patients, of whom only 2 (13.3%) died of systemic metastasis. N-myc amplification did not correlate with positive circulating tumor cell. A certain population of neuroblastoma may provide circulating tumor cells from the early period of the disease to form metastatic lesions independently of the primary lesion, which must be regulated by factors other than N-myc. Circulating tumor cells may suggest higher risk for systemic dissemination and poor prognosis.

Unusual chromaffin cell differentiation of a neuroblastoma after chemotherapy and radiotherapy: report of an autopsy case with immunohistochemical evaluations.

Neuroblastomas are derived from neural crest cells that are capable of multilineage differentiation. Ganglionic neuronal differentiation of childhood neuroblastoma is seen with increasing age, leading to more differentiated tumors called ganglioneuroblastomas or ganglioneuromas. Despite the fact that neuroblastomas most often arise from the adrenal medulla, chromaffin-cell differentiation in neuroblastomas is not widely recognized. Tumor cells with a chromaffin-cell nature have only been detected using histochemical techniques in neuroblastoma cell lines or focal areas of certain in vivo tumors. We describe a neuroblastoma that exhibited an unusual differentiation toward chromaffin cells in a patient that had been treated with surgery, intensive chemotherapy, and radiotherapy. Although a biopsy specimen of the retroperitoneal primary tumor was extensively necrotic, possibly because of a previous chemotherapy regimen, surgically resected metastatic tumors of bilateral ovaries were viable and diagnosed as poorly differentiated neuroblastomas according to the International Neuroblastoma Pathology Classification system. However, metastatic tumors of bilateral lungs examined at the time of autopsy exhibited histologic features similar to those of a pheochromocytoma/paraganglioma, and immunohistochemical examinations demonstrated that these tumors were composed of extra-adrenal chromaffin cells. This case confirms that neuroblastomas in childhood can transform into pheochromocytoma/paraganglioma-like tumors under special conditions.

Pediatric high-flow, cervical spinal, macro-arteriovenous fistula, treated with the endovascular cotton candy glue injection technique

Case reportA 3-year-old boy presented to our hospital with progressive neurological deficits. Spinal magnetic resonance imaging (MRI) revealed a perimedullary macro-arteriovenous fistula (PMAVF) resulting in a large venous pouch within the parenchyma of the lower cervical spinal cord.Transarterial varix embolization of the fistula from the venous side was performed using N-butyl cyanoacrylate with tantalum powder. Postembolization angiography confirmed obliteration of the fistula, and MRI revealed thrombosis and reduction in size of the venous component. The patient’s clinical symptoms were reduced dramatically following the intervention, and no neurological complications occurred due to the treatment. The prognosis of spinal PMAVF depends primarily on the presence of medullar signs and symptoms and on time to treatment. The volume of the venous pouch after the intervention was markedly reduced, and complete clinical recovery was obtained. Urgent endovascular intervention, as seen in this case, is considered first-line therapy and aims to decrease the risk of neurological sequela.