Patterns and predictors of site-specific recurrence in cervical cancer after radical hysterectomy.

AIM: This study examines patterns and predictors of site-specific recurrence to explore the causes of local recurrence of cervical cancer. METHODS: Radical hysterectomy was performed in 121 patients (stage IB-IIB). Nerve-sparing was performed whenever possible. The first recurrence in local, regional, and distant areas was examined. We investigated the possibility of nerve involvement in local recurrence, focusing on paravaginal tissues containing the pelvic plexus. We provide Supporting Information on local recurrence in the paravaginal area. RESULTS: Local recurrence was an independent event from regional or distant recurrence. Local recurrence was seen only in high-risk patients, while regional and distant recurrences were not or less related to the risk category. The independent risk factors by logistic regression for local, regional, and distant recurrence were parametrial invasion, vaginal invasion, and lymph node metastasis, respectively. Local recurrence showed a comparable or more significant negative impact on survival than distant recurrence. Among seven patients with local recurrences, five had a recurrence in the paravagina. The rate of paravaginal recurrence was one in 76 early-stage and four in 45 locally advanced diseases. Four sites of paravaginal recurrence occurred on the nerve-sparing side and two on the non-nerve-sparing side. Supporting Information demonstrated histological evidence of perineural spread into the pelvic plexus and perineural invasion of the primary tumor. CONCLUSIONS: A high percentage of local recurrences are in paravaginal tissue containing the pelvic plexus. The causal association of nerve-sparing surgery and perineural invasion with local recurrence needs to be investigated in large prospective studies.

Preclinical investigation of folate receptor-targeted nanoparticles for photodynamic therapy of malignant pleural mesothelioma.

Photodynamic therapy (PDT) following lung-sparing extended pleurectomy for malignant pleural mesothelioma (MPM) has been investigated as a potential means to kill residual microscopic cells. High expression levels of folate receptor 1 (FOLR1) have been reported in MPM; therefore, targeting FOLR1 has been considered a novel potential strategy. The present study developed FOLR1­targeting porphyrin-lipid nanoparticles (folate-porphysomes, FP) for the treatment of PDT. Furthermore, inhibition of activated epidermal growth factor (EGFR)-associated survival pathways enhance PDT efficacy. In the present study, these approaches were combined; FP-based PDT was used together with an EGFR-tyrosine kinase inhibitor (EGFR-TKI). The frequency of FOLR1 and EGFR expression in MPM was analyzed using tissue microarrays. Confocal microscopy and a cell viability assay were performed to confirm the specificity of FOLR1­targeting cellular uptake and photocytotoxicity in vitro. In vivo fluorescence activation and therapeutic efficacy were subsequently examined. The effects of EGFR-TKI were also assessed in vitro. The in vivo combined antitumor effect of EGFR-TKI and FP-PDT was then evaluated. The results revealed that FOLR1 and EGFR were expressed in 79 and 89% of MPM samples, respectively. In addition, intracellular uptake of FP corresponded well with FOLR1 expression. When MPM cells were incubated with FP and then irradiated at 671 nm, there was significant in vitro cell death, which was inhibited in the presence of free folic acid, thus suggesting the specificity of FPs. FOLR1 targeting resulted in disassembly of the porphysomes and subsequent fluorescence activation in intrathoracic disseminated MPM tumors, as demonstrated by ex vivo tissue imaging. FP-PDT resulted in significant cellular damage and apoptosis in vivo. Furthermore, the combination of pretreatment with EGFR-TKI and FP-PDT induced a marked improvement of treatment responses. In conclusion, FP-based PDT induced selective destruction of MPM cells based on FOLR1 targeting, and pretreatment with EGFR-TKI further enhanced the therapeutic response.

Usefulness of PET/CT for early detection of internal malignancies in patients with Muir-Torre syndrome: report of two cases.

BACKGROUND: Muir-Torre syndrome (MTS) is a rare autosomal dominant genodermatosis caused by mutations in mismatch repair genes. It is characterized by the presence of at least one sebaceous skin tumor associated with internal malignancies. Whether positron emission tomography/computed tomography (PET/CT) is useful for the detection of malignancies in patients with MTS has not been determined. We herein report two cases in which PET/CT was useful for the diagnosis and follow-up of internal malignancies in patients with MTS. CASE PRESENTATION: In case 1, a 57-year-old woman underwent excision of a sebaceous carcinoma on the left upper eyelid. She underwent follow-up PET/CT once yearly thereafter. Forty-two months after the eyelid surgery, PET/CT showed intense tracer uptake in the right lower abdomen. An ascending colon tumor was identified, and examination of a biopsy specimen showed adenocarcinoma. In case 2, a 77-year-old man presented for evaluation of three continuous papules with telangiectasia on his right cheek. Examination of a skin biopsy specimen of the cheek papule revealed a sebaceous carcinoma. He underwent PET/CT to detect other malignancies. PET/CT showed intense tracer uptake in the sigmoid colon. A sigmoid colon tumor was identified, and examination of a biopsy specimen showed adenocarcinoma. Both patients underwent resection of their tumors, and both were still free of recurrence of the sebaceous and colon carcinomas at the time of this writing. CONCLUSION: PET/CT is a reliable imaging modality for the detection of internal malignancies and is useful for the diagnosis and follow-up of MTS.

SORORIN and PLK1 as potential therapeutic targets in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive type of cancer of the thoracic cavity commonly associated with asbestos exposure and a high mortality rate. There is a need for new molecular targets for the development of more effective therapies for MPM. Using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and an RNA interference-based screening, we examined the SORORIN gene as potential therapeutic targets for MPM in addition to the PLK1 gene, which is known for kinase of SORORIN. Following in vitro investigation of the effects of target silencing on MPM cells, cell cycle analyses were performed. SORORIN expression was analyzed immunohistochemically using a total of 53 MPM samples on tissue microarray. SORORIN was found to be overexpressed in the majority of clinical MPM samples and human MPM cell lines as determined by qRT-PCR. Gene suppression of each SORORIN and PLK1 led to growth inhibition in MPM cell lines. Knockdown of SORORIN showed an increased number of G2M-phase population and a larger nuclear size, suggesting mitotic arrest. High expression of SORORIN (SORORIN-H) was found in 50.9% of all the MPM cases, and there is a tendency towards poorer prognosis for the SORORIN-H group but the difference is not significant. Suppression of SORORIN with PLK1 inhibitor BI 6727 showed a combinational growth suppressive effect on MPM cell growth. Given high-dose PLK1 inhibitor induced drug-related adverse effects in several clinical trials, our results suggest inhibition SORORIN-PLK1 axis may hold promise for the treatment of MPMs.

[Pineal Parenchymal Tumor with Marked Cytologic Pleomorphism: Is there a Correlation with the Malignancy Grade?].

INTRODUCTION: In benign pineal parenchymal tumors (PPTs), namely, pineocytoma(PC)and PPT of intermediate differentiation (PPTID), cytologic pleomorphism has occasionally been found;however, it is controversial as to whether the presence of pleomorphic cells leads to upgrading of tumors. We experienced a rare case of pleomorphic PPT in an elderly woman and compared it with a retrospective series of 12 PPTs (PC:3, PPTID:6, pineoblastoma[PB]:3)to evaluate the correlation between pleomorphism and the malignancy grade. CASE AND MATERIALS: A 76-year-old woman presented with gradual cognitive deterioration and gait disturbance. Gadolinium-enhanced magnetic resonance imaging(Gd-MRI)revealed a small, enhanced tumor in the pineal gland with marked hydrocephalus. Endoscopic tumor biopsy and third ventriculostomy were performed simultaneously. The tumor was soft, pinkish, and slightly hemorrhagic. After the biopsy, the patient underwent gamma knife radiosurgery. PATHOLOGICAL FINDINGS: The PPT presented with areas of tumor cells forming pineocytomatous rosettes and areas of giant and multinucleated cells with hyperchromatic nuclei. Neither mitosis nor necrosis was observed. The tumor cells were positive for synaptophysin(SYN)and neurofilament(NF), but negative for glial fibrillary acidic protein(GFAP)and oligodendrocyte lineage transcription factor 2 (Olig2). The MIB-1 labeling index(LI)was 8.1%. There was no difference in the MIB-1 LI between pleomorphic and non-pleomorphic areas. All the 12 PPTs were immunopositive for the neuronal markers SYN and NF. The MIB-1 LI was 0% in PC, 3.5% in PPTID, and 10.5% in PB. The proliferative potential was correlated with the WHO grade. From these findings, the final diagnosis of this pleomorphic case was PPTID grade II, not PC, because the MIB-1 LI was relatively high, even though some tumor cells were forming pineocytomatous rosettes. CONCLUSION: Although cytologic pleomorphism in PPTs is generally considered not to be correlated with the malignancy grade, the final pathological diagnosis should be determined while considering the proliferative potential.

Kinesin family members KIF11 and KIF23 as potential therapeutic targets in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare and aggressive form of cancer commonly associated with asbestos exposure that stems from the thoracic mesothelium with high mortality rate. Currently, treatment options for MPM are limited, and new molecular targets for treatments are urgently needed. Using quantitative reverse transcription-polymerase chain reaction (RT-PCR) and an RNA interference-based screening, we screened two kinesin family members as potential therapeutic targets for MPM. Following in vitro investigation of the target silencing effects on MPM cells, a total of 53 MPMs were analyzed immunohistochemically with tissue microarray. KIF11 and KIF23 transcripts were found to be overexpressed in the majority of clinical MPM samples as well as human MPM cell lines as determined by quantitative RT-PCR. Gene knockdown in MPM cell lines identified growth inhibition following knockdown of KIF11 and KIF23. High expression of KIF11 (KIF11-H) and KIF23 (KIF23-H) were found in 43.4 and 50.9% of all the MPM cases, respectively. Patients who received curative resection with tumors displaying KIF23-H showed shorter overall survival (P=0.0194). These results provide that inhibition of KIF11 and KIF23 may hold promise for treatment of MPMs, raising the possibility that kinesin-based drug targets may be developed in the future.

Anemia in a neonate with placental mesenchymal dysplasia.

Causes of intrauterine fetal death (IUFD) are uncertain in most placental mesenchymal dysplasia (PMD) cases. Our case showed high α-fetoprotein levels in the maternal circulation, markedly dilated subchorionic vessels, and neonatal hemoglobin concentration of 8.4 g/dL, suggesting that fetal anemia may explain some adverse outcomes in PMD pregnancies.

Diagnostic efficacy of cell block method for vitreoretinal lymphoma.

BACKGROUND: Vitreoretinal lymphoma (VRL) is a life- and sight-threatening disorder. The aim of this study was to analyze the usefulness of the cell block method for diagnosis of VRL. METHODS: Sixteen eyes in 12 patients with VRL, and 4 eyes in 4 patients with idiopathic uveitis presenting with vitreous opacity were enrolled in this study. Both undiluted vitreous and diluted fluids were isolated during micro-incision vitrectomy. Cell block specimens were prepared in 19 eyes from diluted fluid containing shredding vitreous. These specimens were then submitted for HE staining as well as immunocytological analyses with antibodies against the B-cell marker CD20, the T-cell marker CD3, and cell proliferation marker Ki67. Conventional smear cytology was applied in 14 eyes with VRL using undiluted vitreous samples. The diagnosis of VRL was made based on the results of cytology, concentrations of interleukin (IL)-10 and IL-6 in undiluted vitreous, and immunoglobulin heavy chain gene rearrangement analysis. RESULTS: Atypical lymphoid cells were identified in 14 out of 15 cell block specimens of VRL (positive rate: 93.3 %), but in 5 out of 14 eyes in conventional smear cytology (positive rate: 35.7 %). Atypical lymphoid cells showed immunoreactivity for CD20 and Ki67. Seven cell block specimens were smear cytology-negative and cell block-positive. The cell block method showed no atypical lymphoid cells in any patient with idiopathic uveitis. CONCLUSIONS: Cell block specimens using diluted vitreous fluid demonstrated a high diagnostic sensitivity and a low pseudo-positive rate for the cytological diagnosis of VRL. The cell block method contributed to clear differentiation between VRL and idiopathic uveitis with vitreous opacity.

A Case of Mature Natural Killer-Cell Neoplasm Manifesting Multiple Choroidal Lesions: Primary Intraocular Natural Killer-Cell Lymphoma.

PURPOSE: Natural killer (NK) cell neoplasm is a rare disease that follows an acute course and has a poor prognosis. It usually emerges from the nose and appears in the ocular tissue as a metastasis. Herein, we describe a case of NK-cell neoplasm in which the eye was considered to be the primary organ. CASE: A 50-year-old female displayed bilateral anterior chamber cells, vitreous opacity, bullous retinal detachment, and multiple white choroidal mass lesions. Although malignant lymphoma or metastatic tumor was suspected, various systemic examinations failed to detect any positive results. A vitrectomy was performed OS; however, histocytological analyses from the vitreous sample showed no definite evidence of malignancy, and IL-10 concentration was low. Enlarged choroidal masses were fused together. Three weeks after the first visit, the patient suddenly developed an attack of fever, night sweat, and hepatic dysfunction, and 5 days later, she passed away due to multiple organ failure. Immunohistochemisty and in situ hybridization revealed the presence of atypical cells positive for CD3, CD56, and Epstein-Barr virus-encoded RNAs, resulting in the diagnosis of NK-cell neoplasm. With the characteristic clinical course, we concluded that this neoplasm was a primary intraocular NK-cell lymphoma. CONCLUSIONS: This is the first report to describe primary intraocular NK-cell neoplasm. When we encounter atypical choroidal lesions, we should consider the possibility of NK-cell lymphoma, even though it is a rare disease.

Two cases of hard metal lung disease showing gradual improvement in pulmonary function after avoiding dust exposure.

We present herein two cases of hard metal lung disease (HMLD) with distinct pathological findings. Both cases showed gradual improvements in pulmonary function over a period of a few years (Case 1: 30 months; Case 2: 12 months) after the avoidance of dust exposure, while improvements on high-resolution computed tomography were modest. The increased lymphocytes and decreased CD4/CD8 ratio in BALF observed at initial diagnosis normalized after the avoidance of dust exposure in one case. To the best of our knowledge, this is the first report demonstrating continual follow-up of pulmonary function and radiographic findings, and a comparison of BALF findings before and after avoidance of hard metal dust exposure.

Importance of luminal membrane mesothelin expression in intraductal papillary mucinous neoplasms.

The present study demonstrated that luminal membrane mesothelin expression is a reliable prognostic factor in gastric cancer. Intraductal papillary mucinous neoplasms (IPMNs) often exhibit a spectrum of dysplasia, ranging between adenoma and carcinoma. Therefore, an immunohistochemical analysis of mesothelin expression in IPMN was performed in the present study, focusing on the localization of mesothelin. IPMNs were classified into two groups, IPMNs associated with invasive carcinoma and low-high (L-H) grade dysplasias. The tumors were classified as mesothelin-positive or -negative and in the mesothelin-positive cases, the localization of mesothelin was evaluated as luminal membrane- or cytoplasmic-positive. Among the 37 IPMNs, mesothelin expression was observed in 21 samples (56.8%), including 46.2% (12 out of 26) of the L-H dysplasia and 81.8% (9 out of 11) of the invasive carcinoma samples (P=0.071). Luminal membrane localization was observed in 10 samples (27%), including 15.4% (4/26) of the L-H dysplasia samples and 54.5% (6 out of 11) of the invasive carcinoma samples (P=0.022). Six patients experienced post-operative recurrence, with five of the recurrent tumors exhibiting mesothelin expression and all six exhibiting luminal membrane localization. It was concluded that immunohistochemical examinations for mesothelin expression and localization are clinically useful for prognostic assessments and decision making regarding further treatment subsequent to surgical procedures in patients with IPMN.

Prognostic factors for survival in patients with high-grade meningioma and recurrence-risk stratification for application of radiotherapy.

BACKGROUND: Radiotherapy for high-grade meningioma (HGM) is one of the essential treatment options for disease control. However, appropriate irradiation timing remains under debate. The object of this study is to discern which prognostic factors impact recurrence in HGM patients and to propose a risk-stratification system for the application of postoperative radiotherapy. METHODS: We retrospectively reviewed 55 adult patients who were diagnosed with Grade II and III intracranial meningioma. Cox regression models were applied to the analysis for impact on early recurrence in HGM patients without postoperative radiotherapy. RESULTS: Grade III malignancy (P = 0.0073) and transformed histology (P = 0.047) proved to be significantly poor prognostic factors of early recurrence by multivariate analysis. The other candidates for recurrence factors were Simpson Grade 3-5 resection, preoperative Karnofsky Performance status < = 70%, and MIB-1 labeling index > = 15%. According to these prognostic factors, postoperative HGM patients could be stratified into three recurrence-risk groups. The prognoses were significantly different between each group, as the 3-year actual recurrence-free rates were 90% in low-risk group, 31% in intermediate-risk group, and 15% in high-risk group. CONCLUSION: We propose recurrence-risk stratification for postoperative HGM patients using clinically available factors. Our results suggest that the prognosis for patients with high-risk HGMs is dismal, whereas HGM patients belonging to the low-risk group could have favorable prognoses. This stratification provides us with the criteria necessary to determine whether to apply adjuvant radiotherapy to postoperative HGM patients, and to also help identify potentially curable HGMs without adjuvant radiotherapy.

microRNA 31 functions as an endometrial cancer oncogene by suppressing Hippo tumor suppressor pathway.

BACKGROUND: We aimed to investigate whether MIR31 is an oncogene in human endometrial cancer and identify the target molecules associated with the malignant phenotype. METHODS: We investigated the growth potentials of MIR31-overexpressing HEC-50B cells in vitro and in vivo. In order to identify the target molecule of MIR31, a luciferase reporter assay was performed, and the corresponding downstream signaling pathway was examined using immunohistochemistry of human endometrial cancer tissues. We also investigated the MIR31 expression in 34 patients according to the postoperative risk of recurrence. RESULTS: The overexpression of MIR31 significantly promoted anchorage-independent growth in vitro and significantly increased the tumor forming potential in vivo. MIR31 significantly suppressed the luciferase activity of mRNA combined with the LATS2 3'-UTR and consequently promoted the translocation of YAP1, a key molecule in the Hippo pathway, into the nucleus. Meanwhile, the nuclear localization of YAP1 increased the transcription of CCND1. Furthermore, the expression levels of MIR31 were significantly increased (10.7-fold) in the patients (n = 27) with a high risk of recurrence compared to that observed in the low-risk patients (n = 7), and this higher expression correlated with a poor survival. CONCLUSIONS: MIR31 functions as an oncogene in endometrial cancer by repressing the Hippo pathway. MIR31 is a potential new molecular marker for predicting the risk of recurrence and prognosis of endometrial cancer.

Differential diagnosis of small cell glioblastoma and anaplastic oligodendroglioma: a case report of an elderly man.

Small cell glioblastoma is a histological subtype of glioblastoma with characteristic features of highly proliferative, monotonous small glial cells with high nuclear cytoplasm ratio. Morphologically, malignant lymphoma or small cell metastatic carcinoma should be carefully discriminated. Some cases are difficult to differentiate from anaplastic oligodendroglioma. In this report, we present a case of small cell glioblastoma of an elderly man. The lack of IDH1/2 mutation was confirmed by immunohistochemistry and direct sequencing. Fluorescence in situ hybridization revealed the lower rates of chromosome 1p and 19q deletion. Microsatellite analysis disclosed partial 10q alteration near the PTEN locus. Not only morphological and immunohistochemical examinations, but also cytogenetical investigations for IDH1/2 mutation, 1p/19q loss, and PTEN alteration, are strongly supportive methods for the differential diagnosis of small cell glioblastoma and anaplastic oligodendroglioma.

Clinicopathological evaluation of cyclooxygenase-2 expression in meningioma: immunohistochemical analysis of 76 cases of low and high-grade meningioma.

Tumorigenic activity of cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the production of prostaglandins (PGs), has been proved for some types of cancer, including brain tumors. We evaluated expression of COX-2 in meningioma, one of the most common intracranial tumors in adults which accounts for 24-30 % of intracranial tumors. We performed immunostaining for COX-2 in 76 cases of meningioma consisting of 44 cases of low-grade (WHO Grade I) and 32 cases of high-grade (29 cases of Grade II and 3 cases of Grade III) meningioma, and evaluated COX-2 expression levels on the basis of staining intensity and proportion in tumor cells. The expression level of COX-2 in meningioma cells was significantly correlated with WHO grade (P = 0.0153). In addition, COX-2 expression was significantly correlated with MIB-1 labeling index for all 76 cases of meningioma (P = 0.0075), suggesting tumor promotion by COX-2 in meningioma progression. Our results may indicate the therapeutic value of non-steroidal anti-inflammatory drugs against meningioma, especially for patients with elevated proliferation, to regulate the tumorigenic activity of COX-2 in meningioma cells.

Clinicopathologic study of pineal parenchymal tumors of intermediate differentiation.

OBJECTIVE: Pineal parenchymal tumors of intermediate differentiation (PPTID) are extremely rare tumor entities, and only limited data are available regarding their pathologic features and biologic behaviors. Because grading criteria of pineal parenchymal tumors (PPTs) have yet to be established, the treatment strategy and prognosis of PPTIDs remain controversial. We describe the clinicopathologic study of six patients with PPTID and compare responses for the treatment and prognosis with cases of pineocytoma (PC) and pineoblastoma (PB). From this analysis, we attempt to clarify the treatment strategy for PPTIDs. METHODS: This study included 15 patients with PPTs, consisting of 6 PCs, 6 PPTIDs, and 3 PBs. We focused on the 6 patients with PPTIDs. All PPTID cases were treated surgically, and radiotherapy and chemotherapy were administered as adjuvant therapies in some cases. We have earlier reported the histopathologic study (Neuropathology 32:647-653, 2012). Briefly, we examined mitotic figures and necrosis by hematoxylin-eosin staining and immunohistochemical markers such as neuronal markers (synaptophysin, neurofilament (NF), and neuronal nuclear antigen), and an MIB-1 labeling index was determined. RESULTS: In the PPTID cases, the extent of resection was variable and the recurrence rates among patients varied according to stage and treatment. All PC patients underwent total resection with no recurrence. All PB patients underwent resection and adjuvant therapy with radiotherapy and chemotherapy. There were no recurrences in patients with PC or PB. The results of histopathologic findings have been already reported as mentioned above. Briefly, the results indicated no mitotic figure or necrosis in any of the six cases of PPTID, but those features were observed in PB cases. All cases even including PC and PB were immunopositive for neuronal markers. The MIB-1 labeling index of PPTID was 3.5%, whereas it was 0% in PC and 10.5% in PB. CONCLUSIONS: Good radiosensitivity of PPTIDs was observed in our series. Because there are cases with discrepancies between images and pathologic findings, it is very difficult to determine the proper treatment strategy for PPTIDs. Proliferative potential was correlated with World Health Organization grade, although the immunoreactivity of neuronal markers did not correlate with the histologic grade.

Large solid-pseudopapillary neoplasm of the pancreas with aberrant protein expression and mutation of ß-catenin: a case report and literature review of the distribution of ß-catenin mutation.

Solid-pseudopapillary neoplasms (SPN) are rare pancreatic tumors. The etiology of SPN involves mutations in the gene that encodes ß-catenin (CTNNB1). We herein report the case of a 23-year-old woman with a large SPN with proliferating tumor cells that displayed both solid and pseudo-papillary patterns. The simultaneous nuclear accumulation and loss of membrane localization of ß-catenin and E-cadherin was specifically observed in the tumor cells. Further, the tumor cells were shown to harbor a missense mutation in exon 3 of CTNNB1. We also present a review of the literature describing the clustering of CTNNB1 mutations in patients with SPN.

Expression of CD163 prevents apoptosis through the production of granulocyte colony-stimulating factor in meningioma.

BACKGROUND: CD163 is a 130-kDa transmembrane protein expressed in human monocytes and macrophages, and the aberrant expression of CD163 in breast and colorectal cancer associated with patients' poor prognosis was reported. Here, we analyzed the expression of CD163 in meningioma, a common intracranial tumor, and its molecular mechanism in association with meningioma progression. METHODS: First, we performed immunohistochemical analysis using 50 human meningioma specimens. Next, we established CD163-overexpressing human meningioma cell lines and investigated its roles in tumor progression in vitro and in vivo. RESULTS: Immunohistochemically, 26 of 50 human meningioma specimens (52.0%) were positive for CD163 in tumor cells, including benign grade I (48.5%) and grade II (71.4%) cases. Furthermore, CD163 expression was correlated with histological atypical parameters that directly predict the prognosis of meningioma. CD163-overexpressing meningioma cells showed significant suppression of apoptosis and accelerated tumor growth in nude mice. In addition, unexpected splenomegaly affiliated with the xenograft predicted tumor-derived granulocyte colony-stimulating factor (G-CSF) production, which was confirmed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. CONCLUSIONS: To our knowledge, this is the first report that demonstrates CD163 expression in meningioma not only by immunohistochemistry but also by reverse-transcription polymerase chain reaction, using primary culture cells, and provides the novel molecular function of CD163 to prevent apoptosis through the production of G-CSF in meningioma.