Makiko Yoshida

Maternal Microchimerism in Underlying Pathogenesis of Biliary Atresia: Quantification and Phenotypes of Maternal Cells in the Liver

OBJECTIVE. The goal was to examine whether microchimerism plays a crucial role in the pathogenesis of biliary atresia; we analyzed the localization of maternal microchimeric cells and their phenotypes. METHODS. Liver biopsy specimens from 8 male infants with biliary atresia and 6 control subjects with other liver diseases were investigated for maternal chimeric cells and their phenotypes through double-staining fluorescence in situ hybridization and immunohistochemical analyses. RESULTS. Significantly larger numbers of maternal XX+ cells were found in the portal area and sinusoids of patients with biliary atresia, in comparison with control patients. In phenotypic analyses of XX+ cells, CD8+ T cells, CD45+ cells, and cytokeratin-positive cells were found, and the numbers and proportions among total CD8+ T cells were significantly higher than those in control patients. CONCLUSIONS. Significantly more maternal chimeric CD8+ T cells in the livers of patients with biliary atresia suggest that maternal immunologic insults represent the underlying pathogenesis in biliary atresia. The findings support the recently postulated mechanisms of alloautoimmune and/or autoalloimmune responses.

A Case of Cerebellar Capillary Hemangioma with Multiple Cysts

Intracranial capillary hemangiomas are very rare, though several spinal capillary hemangiomas have recently been reported. We report here a case of intracranial capillary hemangioma with multiple cysts and review the current literature of similar cases. A 4-month-old girl was referred to our hospital for treatment of hydrocephalus and a cerebellar mass lesion. She presented with hemangiomas distributed widely over the body, as well as disseminated hemangiomas in the pleura, liver, spleen, pancreas, kidneys and vagina. Pathological examination of the specimen from the vagina confirmed the diagnosis of a capillary hemangioma made at another hospital. Radiological examination of the brain revealed a cystic mass lesion in the left cerebellar hemisphere with subsequent obstructive hydrocephalus. The cysts extended upward into the bilateral ventricle. Following neuroendoscopic fenestration of the cysts, resection of the left cerebellar mass was performed. Histological examination of the lesion demonstrated similarly sized capillaries, and the pathological diagnosis was confirmed as capillary hemangioma. There was no recurrence postoperatively. Our patient was treated successfully by surgical resection and neuroendoscopic procedures. Surgical intervention may therefore be indicated in intracranial capillary hemangiomas.

Coexisting Brenner tumor and struma ovarii in the right ovary: Case report and review of the literature

A bilateral ovarian tumor composed of mixed Brenner tumor and struma ovarii in the right ovary and mature cystic teratoma in the left ovary, is described. Mixed Brenner tumor and struma ovarii is rare; eight cases are reviewed. In this case, in addition to the typical Brenner tumor and struma ovarii, some nests composed of both Brenner tumor and struma ovarii in one nest were found in the right ovarian tumor. Immunohistochemically, the struma ovarii is stained for thyroglobulin, and Brenner nests showed various degrees of positive stain for thyroglobulin, which is a specific finding. Brenner tumor, in this case, may produce thyroglobulin or have a receptor to thyroglobulin or analog of thyroglobulin. The origin of mixed Brenner tumor and struma ovarii may be germ cell, as described in some literature, or the Brenner tumor may be of a metaplastic nature, although the Brenner tumor is fourfold the size of struma ovarii in the case presented.

Collaboration of cancer-associated fibroblasts and tumour-associated macrophages for neuroblastoma development.

Neuroblastoma is the most common extracranial solid tumour in children and is histologically classified by its Schwannian stromal cells. Although having fewer Schwannian stromal cells is generally associated with more aggressive phenotypes, the exact roles of other stromal cells (mainly macrophages and fibroblasts) are unclear. Here, we examined 41 cases of neuroblastoma using immunohistochemistry for the tumour‐associated macrophage (TAM) markers CD68, CD163, and CD204, and a cancer‐associated fibroblast (CAF) marker, alpha smooth muscle actin (αSMA). Each case was assigned to low/high groups on the basis of the number of TAMs or three groups on the basis of the αSMA‐staining area for CAFs. Both the number of TAMs and the area of CAFs were significantly correlated with clinical stage, MYCN amplification, bone marrow metastasis, histological classification, histological type, and risk classification. Furthermore, TAM settled in the vicinity of the CAF area, suggesting their close interaction within the tumour microenvironment. We next determined the effects of conditioned medium of a neuroblastoma cell line (NBCM) on bone marrow‐derived mesenchymal stem cells (BM‐MSCs) and peripheral blood mononuclear cell (PBMC)‐derived macrophages in vitro. The TAM markers CD163 and CD204 were significantly up‐regulated in PBMC‐derived macrophages treated with NBCM. The expression of αSMA by BM‐MSCs was increased in NBCM‐treated cells. Co‐culturing with CAF‐like BM‐MSCs did not enhance the invasive ability but supported the proliferation of tumour cells, whereas tumour cells co‐cultured with TAM‐like macrophages had the opposite effect. Intriguingly, TAM‐like macrophages enhanced not only the invasive abilities of tumour cells and BM‐MSCs but also the proliferation of BM‐MSCs. CXCL2 secreted from TAM‐like macrophages plays an important role in tumour invasiveness. Taken together, these results indicate that PBMC‐derived macrophages and BM‐MSCs are recruited to a tumour site and activated into TAMs and CAFs, respectively, followed by the formation of favourable environments for neuroblastoma progression.

Pediatric orbital schwannoma originating from the oculomotor nerve

Intraorbital schwannoma is a rare tumor that constitutes approximately 1%-8% of all orbital tumors. The authors report a case of orbital schwannoma in a 5-year-old boy who was admitted to their institute with exophthalmos and ptosis of the right eye. Computed tomography scanning and MR imaging revealed a retroocular mass in the right orbit. The tumor was successfully removed via a transcranial approach. The pathological diagnosis was schwannoma that appeared to originate from the superior branch of the oculomotor nerve. Despite the rarity of these intraorbital extraocular tumors in children, schwannomas should be differentiated from other intraorbital tumors.

Sacrococcygeal yolk sac tumor developing after teratoma: a clinicopathological study of pediatric sacrococcygeal germ cell tumors and a proposal of the pathogenesis of sacrococcygeal yolk sac tumors.

PURPOSE We evaluated the clinicopathological characteristics of pediatric sacrococcygeal germ cell tumors (SGCTs) and yolk sac tumors (YSTs) developing after sacrococcygeal teratoma (SCT) resection, and discussed the pathogenesis of sacrococcygeal YST. METHODS We retrospectively analyzed pediatric SGCT patients attending 10 Japanese institutions. RESULTS A total of 289 patients were eligible, of which 74.6% were girls. The mean age at surgery was 7.1months. There were 194 mature and 47 immature teratomas, and 48 YSTs. YST developed after SCT resection in 13 patients (5.4% of SCTs), and was detected between 5 and 30months after resection. At initial surgery, 9 of these 13 patients were neonates, 12 underwent gross complete resection with coccygectomy, and 9 had histologically mature teratoma without microscopic YST foci. Postoperative serum alpha-fetoprotein (AFP) levels were regularly examined in 11 patients. Intervals of AFP measurement≤4months helped to detect subclinical localized YSTs for resection. CONCLUSIONS The characteristics of SGCT in Japanese children were similar with those reported in Europe or the United States. YST developed after SCT resection not only in patients with previously reported risk factors. We recommend that patients undergo serum AFP monitoring every 3months for≥3years after SCT resection.

Gonadotropin-independent precocious puberty associated with a somatic activating mutation of the LH receptor gene: detection of a mutation present in only a small fraction of cells from testicular tissue using wild-type blocking polymerase chain reaction and laser-capture microdissection

Objective Leydig cells are the principal source of testosterone, and boys with Leydig cell tumors typically have signs of gonadotropin-independent precocious puberty as a result of testosterone secretion by the tumor. A single somatic activating mutation of the LH receptor gene, Asp578His, limited to the tumoral Leydig cells, has been described in a few boys with gonadotropin-independent precocious puberty. We report a molecular study of a boy with gonadotropin-independent precocious puberty caused by a Leydig cell tumor. Design and setting This is a clinical case report from the Kobe Children’s Hospital. Patient and methods One patient with gonadotropin-independent precocious puberty caused by a Leydig cell tumor underwent a left orchidectomy. We performed a genetic study of the tumoral Leydig cells. Result Using wild-type blocking PCR (WTB-PCR) and laser-capture microdissection (LCM), we found that the Asp578His mutation of the LH receptor gene was exclusively localized to the tumoral Leydig cells and was absent in the adjacent normal tissue and leukocytes. Conclusions WTB-PCR and LCM are powerful techniques that can detect a somatic mutation present in only a small fraction of cells from heterozygous tissue samples.

Optimized Surgical Approach to Third Ventricular Choroid Plexus Papillomas of Young Children Based on Anatomical Variations

BACKGROUND Choroid plexus papilloma (CPP) in the third ventricle is a rare benign intracranial tumor. METHODS We report 3 pediatric cases of CPP in the third ventricle. The lesions were totally removed by a different surgical approach in each case. RESULTS When remarkable hydrocephalus is present, the transcortical approach is easier to perform, but may expose the patient to epilepsy and subdural effusion postoperatively. The transcallosal approach offers direct exposure of the ventricle system with minimal risk of cortical damage. The transcallosal-transforaminal approach with posterior enlargement of the foramen of Monro along the choroidal fissure provides a direct trajectory into the third ventricle through the natural cleft. The transcallosal-interforniceal approach does not depend on the size of the foramen of Monro, but it carries a risk for damage to the both fornices. The midline plane of the septum pellucidum and the forniceal columns in children are sometimes easily identifiable and separable, and in such cases the transcallosal-interforniceal approach appears to be a safe route for tumors extending to the posterior third ventricle. The interforniceal approach should be reserved for lesions that cannot be removed safely via the transforaminal approach. CONCLUSIONS Young children have a small total blood volume and fragile cardiovascular status. Therefore, it is critical to preserve the venous system and to ligate the feeding artery before extirpation of the tumor. The surgical approach to the third ventricular CPPs should be tailored to individual children based on tumor size, location, and vascularity.

Ependymoma with "granular cell" features: report of two cases.

We report two cases of ependymoma which showed prominent “granular cell” changes of the cytoplasm. The patients were a 7‐year‐old boy with a tumor in the cerebellum (case 1) and a 70‐year‐old man with a tumor in the frontal lobe (case 2). The tumor of case 1 showed a histopathological appearance of ependymoma containing many focal aggregates of large polygonal cells in which the cytoplasm was stuffed with numerous eosinophilic granules. The tumor of case 2 predominantly showed the features of papillary ependymoma, and some tumor cells were swollen and contained similar eosinophilic granules. Intracytoplasmic granules in both tumors were immunoreactive for GFAP and ubiquitin, but not for epithelial membrane antigen, CD68 or mitochondria. Ultrastructurally, they were found as aggregates of membrane‐bound, electron‐dense, globular structures. Karyotypic analysis of the tumor in case 1 demonstrated 2, 11 and 12 trisomies. Intracytoplasmic eosinophilic granules occasionally occur in astrocytic and oligodendroglial neoplasms, but an appearance of similar granules is very rare in ependymoma. The two cases presented here may represent a new histopathological variant of ependymoma, and the term “granular cell ependymoma” is appropriate for them.

Involvement of WNT Signaling in the Regulation of Gestational Age-Dependent Umbilical Cord-Derived Mesenchymal Stem Cell Proliferation

Mesenchymal stem cells (MSCs) are a heterogeneous cell population that is isolated initially from the bone marrow (BM) and subsequently almost all tissues including umbilical cord (UC). UC-derived MSCs (UC-MSCs) have attracted an increasing attention as a source for cell therapy against various degenerative diseases due to their vigorous proliferation and differentiation. Although the cell proliferation and differentiation of BM-derived MSCs is known to decline with age, the functional difference between preterm and term UC-MSCs is poorly characterized. In the present study, we isolated UC-MSCs from 23 infants delivered at 22–40 weeks of gestation and analyzed their gene expression and cell proliferation. Microarray analysis revealed that global gene expression in preterm UC-MSCs was distinct from term UC-MSCs. WNT signaling impacts on a variety of tissue stem cell proliferation and differentiation, and its pathway genes were enriched in differentially expressed genes between preterm and term UC-MSCs. Cell proliferation of preterm UC-MSCs was significantly enhanced compared to term UC-MSCs and counteracted by WNT signaling inhibitor XAV939. Furthermore, WNT2B expression in UC-MSCs showed a significant negative correlation with gestational age (GA). These results suggest that WNT signaling is involved in the regulation of GA-dependent UC-MSC proliferation.