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Purpose: Testicular germ cell tumors (TGCT) have a unique epigenetic profile distinct from that of other types of cancer. Elucidation of these properties has a potential to identify novel markers for TGCTs.Experimental Design: We conducted comprehensive analysis of DNA methyltransferase (DNMT) gene expression in TGCTs. Based on the expression profiles of DNMT genes in TGCTs, we generated a rabbit polyclonal anti-human DNMT3L antibody. We then studied the role of DNMT3L in TGCTs by the treatment of two embryonal carcinoma (EC) cell lines with a small interfering RNA system. Finally, we evaluated the immunohistochemical detection of DNMT3L in TGCT tissues. We also compared the patterns of DNMT3L immunohistochemistry with those of CD30 and SOX2.Results: Among the DNMT genes, we found that mRNA for DNMT3L was specifically expressed in TGCTs, but neither in normal testicular tissues nor in cancer cells of somatic tissue origin. DNMT3L protein was strongly expressed in two EC cell lines, but not in the cell lines of somatic tissue origin. Transfection of small interfering RNA for DNMT3L significantly reduced DNMT3L expression and resulted in growth suppression and apoptosis in EC cells. Immunohistochemical analysis showed that DNMT3L protein was present only in EC cells, but not in the other types of TGCT components and cancer cells of somatic tissue origin. DNMT3L staining was more prominent and specific than CD30 or SOX2 staining for detecting EC cells.Conclusion: DNMT3L is a novel marker and is essential for the growth of human embryonal carcinoma. Clin Cancer Res; 16(10); 2751–9. ©2010 AACR.

Supplementary Data from DNMT3L Is a Novel Marker and Is Essential for the Growth of Human Embryonal Carcinoma

Supplementary Figure 1 from RECQL1 and WRN Proteins Are Potential Therapeutic Targets in Head and Neck Squamous Cell Carcinoma

Supplementary Figure 3 from RECQL1 and WRN Proteins Are Potential Therapeutic Targets in Head and Neck Squamous Cell Carcinoma

Supplementary Figure 2 from RECQL1 and WRN Proteins Are Potential Therapeutic Targets in Head and Neck Squamous Cell Carcinoma

Supplementary Figure 4 from RECQL1 and WRN Proteins Are Potential Therapeutic Targets in Head and Neck Squamous Cell Carcinoma

A case of olfactory neuroblastoma (ONB) associated with extensive intraepithelial neoplastic proliferation, evidenced by an "in situ" lesion, in the overlying olfactory epithelium and aberrant glandular and rhabdomyosarcomatous differentiation is reported. The tumor was a polypoid lesion that involved the upper nasal cavity and ethmoid sinus of a 63-year-old woman and consisted of an ONB surrounded by and mixed with a proliferative lesion of rhabdomyoblastic cells, consistent with an embryonal rhabdomyosarcoma. A few small foci of tubular glands with mucus-producing cells were also observed. In the olfactory epithelium covering the polypoid lesion, a nested or band-like arrangement of primitive-appearing small cells was found, and the tumor cells were immunoreactive for epithelial cell adhesion molecule (detected with Ber-EP4) and low-molecular weight cytokeratin (detected with CAM5.2) but not for synaptophysin or calretinin. The intraepithelial lesion was contiguous with the subepithelial cell nests of ONB and appeared to invade the subjacent stroma and show transition to ONB, and some tumor cell nests of ONB also contained small aggregates of similar primitive-appearing cells. The intraepithelial growth was considered to represent a preinvasive precursor lesion of ONB. Previous descriptions of an "in situ" lesion in ONB are limited. The aberrant glandular and rhabdomyosarcomatous differentiation noted in this case is also an exceptionally rare phenomenon of ONB.

We present two autopsy cases of refractory ascites/hydrothorax associated with systemic deposition of low-molecular weight dextran that had been used in hemodialysis over an extended period. The most striking autopsy findings in both cases were dense accumulation of dextran-laden macrophages in sinusoids of reticuloendothelial organs. These accumulated macrophages seemed to have disturbed blood and lymph flow. Based on these findings, we concluded that the persistent ascites and hydrothorax were attributable to systemic deposition of dextran, especially the accumulation of dextran-laden macrophages in the reticuloendothelial organs. We suggest that dextran solution should immediately be designated as contraindicated for hemodialysis patients.

We report a case of classical Hodgkin lymphoma type post-transplant lymphoproliferative disorder (HL-PTLD) after kidney transplantation to highlight the difficulty of distinguishing this disorder from Hodgkin lymphoma-like PTLD (HL-like PTLD). Through this case report and literature review, we seek to clarify definitive pathologic features to differentiate these two conditions. A 38-year-old male kidney transplant recipient who had been receiving immunosuppressants was admitted to our hospital with unidentified high fever. Computed tomography images and blood tests indicated a lymphoproliferative disorder. Abdominal lymph node biopsy was performed, and microscopic examination revealed the presence of many large atypical cells in a background of dense T cell accumulation. The large, atypical cells were positive for Epstein-Barr Virus (EBV)-encoded small RNAs (EBER) in situ hybridization, EBV-LMP1, CD30 and PAX5, but negative for CD15, CD20 and CD45. Except for CD15-negativity, this immunohistochemical pattern was consistent with that of classical Hodgkin lymphoma. By close examination of the above immunoreactivities and the patient's subsequent chemosensitive clinical course, we finally made a diagnosis of HL-PTLD.

Background:To better understand the nature of magnetic resonance imaging (MRI) findings in schwannomas, especially in the "target sign" of these findings, the histopathological investigation was performed., Methods:The MRI findings were correlated with histopathological features in 22 samples of schwannomas, which were mostly resected from the extremities. The histopathological analyses included alcian blue staining and immunohistochemical staining for S-100 protein, proliferating cell nuclear antigen (PCNA) and epithelial membrane antigen (EMA)., Results:Seven of the 22 samples of schwannomas of the extremities exhibited target signs including a peripheral zone of homogeneously high signal intensity and a central zone of heterogeneous signal intensity in T2-weighted images. Gadolinium-enhanced T1-weighted images demonstrated a central heterogeneous enhancement and a peripheral ring of homogeneously low signal intensity. Histopathologically, S-100 and PCNA were positive only in the central heterogeneous signal area. In contrast, EMA was only stained on the degenerative epi/perineurium in the peripheral zone., Conclusion:In schwannomas of the extremities showing target sign in T2-weighted images, histopathologically, the peripheral areas were suggested to be mucinous degeneration of the epineurium or perineurium, while the central areas were composed of truly neoplastic cells.

Wagner-Meissner corpuscles are specialized mechanoreceptors located in the dermal papillae. Wagner-Meissner corpuscle-like structures are occasionally a component of certain types of tumors, such as melanocytic nevus and neurofibroma. Benign tumorous lesion entirely composed of Wagner-Meissner corpuscles are described as Wagner-Meissner neurilemmoma, and only four such cases have been reported. Here, we report the first case of Wagner-Meissner neurilemmoma in a patient with neurofibromatosis type 1. A 16-year-old Japanese male with neurofibromatosis type 1 presented with a tumorous lesion on the upper lip. Resection of the tumor was performed under a clinical diagnosis of neurofibroma. Histopathological examination revealed an unencapsulated, poorly-circumscribed tumor, comprised of abundant Wagner-Meissner corpuscle-like structures, which were composed of 5-15 lamellated Schwann cells containing eosinophilic cytoplasm and peripherally located nuclei. No spindle-shaped neoplastic cell proliferation, as seen in conventional neurofibroma, was observed. Accordingly, a diagnosis of Wagner-Meissner neurilemmoma was made. The pathogenesis of Wagner-Meissner neurilemmoma remains unclear. The hamartomatous or reactive proliferative nature has been proposed. In addition, this lesion may represent an extreme form of diffuse neurofibroma with abundant Wagner-Meissner corpuscles associated with neurofibromatosis type 1, even though the previously reported four patients did not have neurofibromatosis. Therefore, further studies are needed to clarify the pathogenesis of this extremely rare tumor, including its association with neurofibromatosis.

Background There have been no reports that show significant direct relationship between echocardiographic parameters and B-type natriuretic peptide (BNP) level. This could be due to the heterogeneous pathophysiology of heart failure and a lack of appropriate echocardiographic parameters. We sought to determine the best echocardiographic parameter that described elevated BNP level in patients with heart failure with and without systolic dysfunction. Methods and Results We studied 111 consecutive heart failure patients. They were divided into patients with heart failure and preserved ejection fraction (HFPEF, n = 61) and that with heart failure and reduced ejection fraction (HFREF, n = 50). Conventional and new echocardiographic parameters including myocardial strains were measured. BNP did not reflect any single echocardiographic parameter in patients with heart failure in total. The ratio of early diastolic transmitral flow velocity and mitral annular velocity had strong positive correlation with BNP level in the HFPEF group but not in the HFREF group. In the group of HFREF, global longitudinal and circumferential strains were positively correlated. Multivariate analysis revealed that predicted factors for BNP value in HFPEF and in HFREF were different. Conclusion High BNP level may indicate high filling pressure when ejection fraction is preserved and may indicate myocardial dysfunction when it is reduced.

Colloid carcinoma, characterized by the presence of a large amount of extracellular mucin that results in the formation of mucous lakes with a relative paucity of neoplastic glandular cells within them, is extremely rare in the uterine cervix. Herein, we report an additional case of colloid carcinoma of the cervix and discuss the immunohistochemical characteristics and histogenesis of this extremely rare tumor. A 47-year-old Japanese female without any history of carcinomas was found to have a bulky mass in the cervix. Biopsy from the cervix revealed adenocarcinoma; subsequently, total hysterectomy was performed. Histopathologic study demonstrated that columnar or cuboidal neoplastic glandular cells forming cribriform or tubular structures floated within the mucous lakes involving almost the entire layer of the cervical wall. Adenocarcinoma in situ (AIS) component was also observed. Immunohistochemically, tumor cells of the colloid carcinoma were positive for cytokeratin 7, MUC5AC, MUC6, and p16 (diffuse), but negative for cytokeratin 20, MUC2, and cdx-2. In addition, human papillomavirus 16 was detected in both colloid carcinoma and AIS components. This is the first reported case of endocervical type colloid carcinoma, and the second documented case of cervical colloid carcinoma with immunohistochemical analyses of mucin. The present case had an endocervical type AIS component, which suggests that AIS may be a precursor lesion of colloid carcinoma. Moreover, this case clearly demonstrates that the occurrence of cervical colloid carcinoma correlates with high-risk human papillomavirus.

Every year, 14 million cases of obstetric hemorrhage occur worldwide, causing 127,000 maternal deaths. About 75% of postpartum hemorrhage cases are due to atonic uterus, which is loss of uterine muscular tone or strength for contraction of the uterus after delivery. The prediction of atonic uterus is therefore important for the prevention of postpartum maternal death. However, prediction of occurrence of atonic uterus is difficult before delivery, because the precise pathophysiological mechanism to trigger this condition remains unclear. Here, we present a case of severe postpartum hemorrhage due to atonic uterus. A 35-year-old woman gave a birth by vaginal delivery to a healthy boy. However, due to intractable massive hemorrhage after the removal of the retained placenta, we performed supravaginal hysterectomy as the best option for survival. Pathological examination showed that implantation site intermediate trophoblasts (ISITs) formed unusually large clumps in the decidua, diagnosed as exaggerated placental site (EPS). EPS is thought to be a condition consisting of an excessive number of ISITs. ISITs are differentiated from a trophoblast lineage in the process of placenta formation. ISITs anchor the placenta to the maternal tissue and are considered to maintain pregnancy, but the postpartum role of these cells remains unclear. Excessive infiltration of ISITs, namely EPS, may cause postpartum atonic uterus. In this article, we also reviewed the literatures on EPS. The present case and other reported cases indicate that EPS causes mass formation in the uterus, continuous uterine bleeding, and massive hemorrhage, resulting in hysterectomy.

To identify new cancer biomarkers and therapeutic targets for colorectal cancers (CRCs), we performed immunohistochemical analysis using tissue microarrays covering archival tumor tissue samples from 434 CRC patients and antibodies to cell division cycle-associated protein 1 (CDCA1) that was originally identified as an oncoantigen by our gene expression profile database, and compared its expression with several clinicopathological factors. Strong CDCA1 positivity was associated with poorer prognosis for patients with CRC (P=0.019) and multivariate analysis confirmed its independent prognostic value. In addition, transfection of siRNAs against CDCA1 suppressed its expression and induced apoptosis of CRC cells. These results suggest that CDCA1 could be a prognostic biomarker and a potential therapeutic target for CRCs.

Adenoid cystic carcinoma (AdCC) is a distinct type of carcinoma, and cytological examination has been recognized as a useful tool in its diagnosis. Dedifferentiation is defined as the abrupt transformation of a low-grade tumor into a tumor with high-grade components. Albeit extremely rare, dedifferentiated AdCC has been reported: however, the cytological features of this tumor have not been documented. We observed a case in which a 66-year-old Japanese male had stenosis and thickness of the lower tracheal and bronchial walls. Cytological smears of a bronchial brush specimen revealed features typical for low-grade AdCC. However, a few cohesive epithelial cell clusters composed of large, atypical polygonal cells with large nuclei and conspicuous nucleoli also were present. This component was considered to represent dedifferentiated carcinoma. Histopathological study of the resected bronchial tumor revealed dedifferentiated AdCC. The cytological diagnosis of conventional low-grade AdCC is straightforward in most cases, although extremely rare, dedifferentiated carcinoma can occur within the conventional AdCC, and detection of a dedifferentiated component is possible in a cytological specimen because of obvious nuclear atypia. Therefore, careful observation is needed because cytologic diagnosis of dedifferentiated AdCC can help expedite treatment of this highly aggressive tumor.

Signet-ring cell melanoma is an extremely rare variant of malignant melanoma. A 68-year-old male presented with a black nodule on the left thigh. Histopathological examination revealed proliferation of sheet-like or variable-sized nests of atypical melanocytes. Neoplastic cells showing signet-ring cell appearance, characterized by the presence of eccentrically located enlarged nuclei and abundant pale cytoplasm, were also present. Immunohistochemically, the tumor cells were positive for S-100 protein, vimentin and Melan-A. Moreover, mammalian target of rapamycin (mTOR) pathway proteins were diffusely expressed. The current case report presents the 21st reported case of signet-ring cell melanoma. Analyses of the clinicopathological features revealed that this disease commonly affects middle-aged males and the presence of metastatic signet-ring cell melanoma with an unknown primary tumor. Immunohistochemical analyses of melanocytic markers have been useful for establishing the diagnosis of this type of disease, however, HMB-45 is occasionally found to be negative. In addition, the present case report is the first to analyze the expression of mTOR pathway proteins, which are central proteins involved in carcinogenesis and its inhibitor has been proposed as a therapeutic target for various types of tumor. Therefore, the mTOR inhibitor may also be a potential candidate for the treatment of this type of tumor.

The occurrence of small cell carcinoma in the urinary bladder and prostate is rare. Only a few reports on the cytological features of small cell carcinoma of the urinary bladder in the urine specimen have been documented and, moreover, the urinary cytological features of prostate small cell carcinoma have been rarely reported. In this study, we analyzed the cytological features of four cases of small cell carcinoma of the urinary bladder and prostate, and discussed the usefulness of cytological examination of urine specimen for this type of tumor. This study included two urinary bladder and two prostate small cell carcinoma cases. Analyses of the cytological features of these cases revealed the following: i) the background was mostly inflammatory and necrotic material was also occasionally observed; ii) numerous tumor cells were present in two cases, whereas only a few neoplastic cells were observed in the remaining cases; iii) the neoplastic cells were small in size, had scant cytoplasm and a high nuclear/cytoplasmic ratio, and were arranged in small clusters or occasionally as single cells; iv) the tumor cell clusters showed prominent nuclear moldings; and v) the nuclei of the neoplastic cells were round to oval in shape with finely granular chromatin containing inconspicuous nucleoli. The cytological features of small cell carcinoma in the urine specimen are characteristic. Therefore, careful observation of the urine specimen may lead to a correct diagnosis of small cell carcinoma of the urinary bladder and, moreover, cytodiagnosis of prostate small cell carcinoma may also be possible.

Acute promyelocytic leukemia (APL) has two morphological variants, namely macrogranular (M3) and microgranular (M3v). M3v, characterized by the presence of neoplastic promyelocytes with only sparse fine azurophilic granules, accounts for 10-25% of all APL and has unique biological characteristics. Relapse occurs in approximately 20% of patients with APL. The morphological type of the leukemic cells at relapse is usually identical with the primary disease, and only one case of morphological change at relapse has been reported. Here, we analyzed the clinicopathological features of APL, including 4 relapsed cases emphasizing morphological changes at the time of relapse. The unique finding of the present study is that 2 of 4 relapsed cases changed from M3 to M3v at relapse. The morphological features of these were different in each case (one had blastic features and the other resembled monocytoid leukemic cells). Cytogenetic analyses revealed the continued presence of t(15;17)(q22;q12) at the time of relapse and morphological change. Moreover, the immune phenotype of the leukemic cells changed from CD2(-)/CD34(-) to CD2(+)/CD34(+) at that time. These findings suggest that morphological change at relapse in APL may not be a rare event, and that the leukemic cells can show variable morphological features at the time of relapse, which could result in misdiagnosis as a different type of acute myeloid leukemia. Therefore, a comprehensive approach with emphasis on combined morphological, immunophenotypic, and cytogenetic analyses is important for diagnosis and appropriate treatment of relapsed APL., 平成25年度

A choriocarcinomatous component is rarely present in carcinomas of certain sites and few cases of choriocarcinomatous differentiation in endometrioid adenocarcinoma have been reported. The present study reports a case of endometrioid adenocarcinoma of the uterine corpus with choriocarcinomatous differentiation, and discusses the clinicopathological features of this rare tumor. A 59-year-old post-menopausal female presented with abnormal vaginal bleeding. Magnetic resonance imaging demonstrated a relatively well-circumscribed tumor in the uterine corpus and a total cystectomy was subsequently performed. A histopathological examination revealed two distinct components in the uterine corpus tumor. The first component comprised ~80% of the tumor and was composed of poorly-differentiated endometrioid adenocarcinoma. The remaining component consisted of mononucleated and syncytial giant cells containing rich eosinophilic cytoplasm and large pleomorphic nuclei with coarse chromatin. An immunohistochemical analysis revealed that these syncytial giant cells were positive for β-human chorionic gonadotropin (hCG). Therefore, a diagnosis of endometrioid adenocarcinoma with choriocarcinomatous differentiation was confirmed. The clinicopathological features of nine previously reported cases of this tumor were analyzed in addition to the present case. The majority of the patients were post-menopausal. Endometrial choriocarcinoma may be considered to have a highly aggressive clinical course, since nine of the 10 cases displayed metastases and four patients succumbed to the disease. The pathogenesis of the choriocarcinomatous component is not well understood. However, genetic studies have demonstrated that conventional carcinoma and choriocarcinomatous components share common genetic alterations. The choriocarcinomatous component represents aberrant differentiation of the conventional carcinoma, however, genetic analyses of endometrioid adenocarcinoma with choriocarcinomatous differentiation have not been performed.

The concurrence of Merkel cell carcinoma (MCC) and squamous cell carcinoma (SCC) is well known, and MCC concurrent with Bowen's disease has also been documented. Herein, we describe two cases of MCC concurrent with Bowen's disease, and one case exhibited an unusual immunophenotype. An 86-year-old male (Patient 1) and an 87-year-old female (Patient 2) presented with nodules of the chest and cheek, respectively. Histopathologic study revealed Bowen's disease and a proliferation of small round cells in the dermis and/or subcutis. Immunohistochemically, the round cells expressed endocrine markers. 'Dot' immunopositivity for cytokeratin (CK) (AE1/AE3) was observed in both patients. However, dot-like CK20 positivity was present only in the second tumor, and thyroid transcription factor-1 (TTF-1) was only positive in the first. Both cases were negative for Merkel cell polyomavirus (MCPyV). MCC concurrent with SCC usually does not involve detectable MCPyV infection, which suggests that combined MCC may develop through different tumorigenetic pathways, such as chronic ultraviolet exposure, as compared to pure MCC. Additionally, concurrent tumors may exhibit an unusual immunophenotype, such as TTF-1(+) /CK20((-)) .

Aldehyde dehydrogenase (ALDH) is an enzyme responsible for oxidizing aldehydes to carbonic acids. ALDH1 is an isoform that is thought to be a stem cell marker as it is highly expressed in the stem cells of various organs. However, its expression in basal cell carcinoma (BCC), actinic keratosis (AK) and Bowen’s disease (BD) of the skin has not yet been analyzed. Twenty-five consecutive operative cases each of BCC, AK and BD, as well as 10 normal skin tissues were assessed for ALDH1 expression by immunohistochemistry. In normal skin, ALDH1 expression was observed in the suprabasal cells of the follicular infundibulum, inner cells of the outer root sheath and sebocytes. BCC cases (88%) showed no or focal-positive immunoreactivity for ALDH1. Focal immunopositivity for ALDH1 was observed in 44% of AK cases, while the remaining cases were ALDH1-negative. By contrast, diffuse positive immunoreactivity for ALDH1 was observed in 64% of BD cases. Differential expression patterns of ALDH1 in AK and BD may reflect the distinct cells of origin of these two conditions. Moreover, a low ALDH1 expression in BCC may also reflect the possible origin of BCC, the basal cells of the outer root sheath.

Intraductal papillary mucinous neoplasm (IPMN) and neuroendocrine tumor (NET) of the pancreas are rare tumors and their association is not expected to be frequent. However, certain studies have suggested that the concomitant occurence of these tumors may be more frequent than previously thought. In the current study, we describe a case of concomitant occurrence of IPMN and NET of the pancreas and review the clinicopathological features of previously published cases and the current one. A 68-year-old female was incidentally found to have dilatation of the main pancreatic duct. A distal pancreatectomy was performed under the clinical diagnosis of IPMN. Histopathological analysis revealed concomitant IPMN (low-grade) and NET G1 of the pancreas. Review of the clinicopathological features of the 15 previously reported cases of concomitant IPMN and NET of the pancreas as well as the present one indicated that: i) this condition mainly affects middle-aged females; ii) the main symptom is abdominal or back pain, or no symptoms; iii) a hormone production symptom was observed in only one case; iv) the most common degree of dysplasia of IPMN is low grade; and v) the size of the NET is not particularly large (average 15.1 mm), although the clinical behavior is not always indolent (metastasis was observed in 3 cases). It is well known that IPMNs are associated with a high incidence of extrapancreatic malignancies, including colorectal and gastric carcinomas. Concomitant pancreatic NET and extrapancreatic malignancies may occur, therefore, systemic surveillance of extrapancreatic neoplasms and detection of concomitant NETs of the pancreas are necessary for patients with IPMN.

For biomedical application of nanoparticles, the surface chemical functionality is very important to impart additional functions, such as solubility and stability in a physiological environment, and targeting specificity as an imaging probe and a drug carrier. Although polyethylene glycol (PEG) has been used extensively, here, it is proposed that hyperbranched polyglycerol (PG) is a good or even better alternative to PEG. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared using a polyol method are directly functionalized with PG through ring-opening polymerization of glycidol. The resulting SPION-PG is highly soluble in pure water (>40 mg mL−1) and in a phosphate buffer solution (>25 mg mL−1). Such high solubility enables separation of SPION-PG according to size using size exclusion chromatography (SEC). The size-separated SPION-PG shows a gradual increase in transverse relaxivity (r2) with increasing particle size. For biological application, SPION-PG is functionalized through multistep organic transformations (–OH → –OTs (tosylate) → –N3 → –RGD) including click chemistry as a key step to impart targeting specificity by immobilization of cyclic RGD peptide (Arg-Gly-Asp-D-Tyr-Lys) on the surface. The targeting effect is demonstrated by the cell experiments; SPION-PG-RGD is taken up by the cells overexpressing αvβ3-integrin such as U87MG and A549.

Systemic Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disease (LPD) of childhood is an extremely rare and distinct clinicopathological entity. The majority of these cases occur with an apparent primary EBV infection. In this study, we describe a case of systemic EBV-positive T-cell LPD of childhood in a 23-year-old female with primary EBV infection, and review the clinicopathological features of this disease. A 23-year-old previously healthy female without an immunocompromized status presented with an acute onset of high fever. Laboratory examinations revealed a markedly elevated white blood cell count and liver and renal function. Peripheral blood smears identified a number of atypical lymphocytes with small azurophilic granules in the cytoplasm. Bone marrow aspiration revealed marked proliferation of small-sized lymphocytes with convoluted nuclei, which expressed EBER1, CD3, CD8 and cytotoxic granules. Monoclonal rearrangements of T-cell receptors were also detected. The patient underwent chemotherapy, but succumbed to multiorgan failure 20 weeks after administration. Upon review of 17 cases of this disease, including the one in the present study, we identified that the major clinicopathological features of systemic EBV-positive T-cell LPD of childhood are as follows: i) clonal systemic proliferation of EBV-infected T-cells that appear morphologically innocuous with an activated cytotoxic phenotype; ii) a high prevalence in the Asian population, commonly affecting children and young adults; iii) a predilection for males; iv) most commonly involved sites are the liver, spleen, lymph node and bone marrow, and the main clinical presentations are hepatosplenomegaly, fever and pancytopenia; v) almost all cases have an aggressive clinical course, which results in mortality. Cytological atypia of the neoplastic cells in this disease, as observed in the present case, is minimal. This study revealed that the cytomorphological features of atypical lymphocytes in the peripheral blood are indistinguishable from those of infectious mononucleosis.

Post-transplant lymphoproliferative disorders (PTLDs) are lymphoid or plasmacytic proliferations that develop as a consequence of immunosuppression in a recipient of a solid organ, bone marrow or stem cell allograft. The development of PTLDs is usually associated with Epstein-Barr virus (EBV) and the disorder is also termed EBV-associated lymphoproliferative disorder (LPD). The development of PTLD is a rare complication in autologous bone marrow/peripheral blood stem cell transplantation. In the present study, we report a case of EBV-associated LPD which developed following autologous peripheral blood stem cell transplantation for relapsing Hodgkin's lymphoma. A 51-year-old male presented with swelling of the left cervical lymph nodes. A biopsy revealed nodular sclerosis classical Hodgkin's lymphoma. Following four courses of ABVd (adriamycin, bleomycin, vinblastine, dacarbazine) therapy, the Hodgkin's lymphoma relapsed. CHASE (cyclophosphamide, etoposide, cytarabine, dexamethasone) therapy and autologous peripheral blood stem cell transplantation were performed. In the 128 days following the transplantation, lymph node swelling was noted and a biopsy specimen demonstrated EBV-associated LPD. The serum copy number of EBV-DNA was 2.7×10(3) copies/ml. The occurrence of EBV-associated LPD may be on the rise due to the increased number of patients undergoing immunosuppression therapy. The measurement of the serum EBV-DNA copy number and the detection of EBV-infected atypical lymphocytes using in situ hybridization are significant in establishing an early accurate diagnosis and initiating the correct treatment for EBV-associated LPD in patients with immunosuppression.

Mucormycosis is a rapidly progressive fungal infection that usually occurs in patients with diabetes mellitus or in immunocompromised patients. Sinus involvement is the most common clinical presentation and the rates of mortality increase with the orbital extension. The treatment of mucormycosis includes aggressive surgical debridement and systemic antifungal therapy. Early diagnosis and prompt initiation of effective antifungal drugs are essential for successful outcome. However, the role of orbital exenteration for the case of orbital involvement remains controversial, and the drugs effective against mucormycosis are limited. We present a successfully treated case with rhino-orbital mucormycosis caused by Rhizopus oryzae in a diabetic and dialysis patient. The early diagnosis, surgical debridement and a new combination therapy with liposomal amphotericin B and micafungin were effective. This new combination antifungal therapy will be useful for the treatment of mucormycosis.

We report a case of thymic papillo-tubular adenocarcinoma in a 55-year-old man, who had no symptoms. Sternotomy revealed a tumor in the anterior mediastinum, tightly adhered to the pericardium. It was resected completely. Interestingly, the tumor contained a unilocular cyst filled with mucinous fluid, suggesting that it originated from a pre-existing thymic cyst. Pathological examination of the tumor revealed a primary thymic papillo-tubular adenocarcinoma resembling a tumor of gut origin. Thymic adenocarcinomas, particularly of the tubular subtype, are extremely rare.

Cytological diagnosis is a valuable method for detection of mediastinal tumors, and recent reports have shown the usefulness of fine-needle aspiration cytology for diagnosis of mediastinal tumors, including germ cell tumors. We report a case of mediastinal seminoma diagnosed intraoperatively by cytological examination of cystic fluid containing tumor cells. An anterior mediastinal tumor with cystic component was incidentally found in a 28-year-old Japanese male. Cytological examination of the cystic fluid at the time of tumor resection showed single and loose aggregates of large round to polygonal cells with large round nuclei, vesicular chromatin and nucleoli, and mild to moderate amounts of PAS-positive cytoplasm admixed with mature lymphocytes. A diagnosis of seminoma was made intraoperatively. On subsequent immunostaining, the tumor cells showed nuclear positivity for SALL4, a recently recognized germ cell marker that, in the appropriate setting, can be helpful to distinguish germ cell tumors from other mediastinal neoplasms, such as malignant lymphoma, thymoma, and thymic carcinoma.

Herpes simplex virus (HSV) infection is usually observed in the oral cavity and external genitals, and HSV peritonitis is extremely rare. Herein, we report a case of type II HSV peritonitis successfully diagnosed by ascitic cytology. A 66-year-old Japanese man, who had been treated with steroid inhalation for 5 years due to chronic obstructive pulmonary disease, was suspected to have acute cholecystitis. Laparoscopic cholecystectomy and intraoperative cytological examination of ascitic fluid were performed. Cytological study of ascitic fluid revealed that abundant granular cell debris, degenerative cells and apoptotic bodies were present, as well as some single or multinucleated cells with ground glass nuclei. However, vivid mesothelial cells were rarely seen. Immunocytochemical staining for type II HSV was positive in single or multinucleated cells with ground glass nuclei. Therefore, a diagnosis of type II HSV peritonitis was made. This is the first reported case of type II HSV peritonitis successfully diagnosed by ascitic cytology. This report highlights that the presence of abundant cell debris, degenerative cells and apoptotic bodies, and the absence of vivid mesothelial cells are the key cytological findings to suspect HSV peritonitis, and the diagnosis can be confirmed by careful surveillance for characteristic nuclear findings of single or multinucleated cells. The frequency of opportunistic infection is increased because of the increased numbers of iatrogenic immunocompromised patients as seen in this case, therefore, cytological examination is a useful method for early detection of the causative agent of peritonitis including HSV.

The presence of nephroblastic components is extremely rare in retroperitoneal teratomas. We described an unusual case of right retroperitoneal immature teratoma with nephroblastic components in a 2-month-old Japanese girl. Approximately 15% of tumor was composed of nephroblastic components within immature teratoma components. Although overlap of histopathological findings between teratomas with nephroblastic components and teratoid Wilms tumors, which have heterologous elements in >50% of the tumor, occasionally exist, the most distinct feature of teratoma is the presence of organoid arrangement. The prognosis of retroperitoneal teratomas with nephroblastic components has not yet been established, therefore, additional case studies are needed.

Glomerulocystic kidneys (GCKs) are mainly observed in infants and young children, and are characterized by the cystic dilatation of Bowman's space to form glomerular cysts (GCs). GCKs are associated with various conditions. Additionally, the cystogenesis of GCKs remains controversial. The present study describes a rare adult case of a sporadic localized GCK that radiologically mimicked a multilocular cystic tumor, and analyses the features of GC. A 42-year-old male with hematuria underwent a right partial nephrectomy for a cystic mass. The majority of the cyst was distributed in the cortex and contained a single collapsed glomerulus. Using serial sections, narrow and serpiginous proximal tubules that continued to the GCs were detected. These findings suggested that obliteration at the glomerulotubular junction was not the primary cause of GC in this case. To the best of our knowledge, this is the first adult case of a sporadic localized GCK mimicking a tumor. Unnecessary surgical procedures may be avoided by careful evaluation of computed tomography scans and magnetic resonance imaging, although localized GCKs are quite rare.

RB1-inducible coiled-coil 1 (RB1CC1) functions in various processes, such as cell growth, differentiation, senescence, apoptosis, and autophagy. The conditional transgenic mice with cartilage-specific RB1CC1 excess that were used in the present study were made for the first time by the Cre-loxP system. Cartilage-specific RB1CC1 excess caused dwarfism in mice without causing obvious abnormalities in endochondral ossification and subsequent skeletal development from embryo to adult. In vitro and in vivo analysis revealed that the dwarf phenotype in cartilaginous RB1CC1 excess was induced by reductions in the total amount of cartilage and the number of cartilaginous cells, following suppressions of type II collagen synthesis and Erk1/2 signals. In addition, we have demonstrated that two kinds of SNPs (T-547C and C-468T) in the human RB1CC1 promoter have significant influence on the self-transcriptional level. Accordingly, human genotypic variants of RB1CC1 that either stimulate or inhibit RB1CC1 transcription in vivo may cause body size variations.

Testicular germ cell tumors (TGCTs) have a unique epigenetic profile distinct from that of other types of cancer. To further evaluate epigenetics of TGCTs, this study examines DNA methylation patterns of DNA repetitive elements in TGCTs. Bisulfite genomic sequencing and combined bisulfite restriction analysis (COBRA) were used to analyze the methylation patterns of DNA repetitive elements (LINE1 and Alu repeats) in embryonal carcinoma (EC) derived cell lines, primary TGCT tissues, noncancerous testicular tissues adjacent to TGCTs and cancer cells derived from somatic tissues (testicular malignant lymphoma tissues and renal cell carcinoma cell lines). Through both bisulfite genomic sequencing and COBRA, LINE1 was extensively hypomethylated in both seminomatous and nonseminomatous TGCT tissues as well as EC cell lines. We studied two Alu repeats locating in the 5' end of E-cadherin and XIST by bisulfite genomic sequencing. These two Alu elements were extensively hypomethylated in seminomatous TGCTs, but methylated in nonseminomatous TGCTs, including two EC derived cell lines. This increased unmethylated profile in seminomatous TGCTs was observed also by COBRA for Alu repeats. Although partial demethylation of DNA repetitive elements was observed in cancer cells of somatic tissue origin, the degree of demethylation was more pronounced in TGCTs than in cancer cells of somatic tissue origin. We observed abnormal demethylation of DNA repetitive elements in some of the tissues adjacent to TGCTs. The results indicate that the underlying mechanisms to undergo or maintain demethylation of DNA repetitive sequences differ between TGCTs and cancer cells of somatic tissue origin.

H. Kataoka, T. K. Kobayashi, S. Amano, E. Yamada, M. Ishida, R. Kushima and H. Okabe Body cavity fluid can induce epithelial and mesothelial differentiation from CD34 positive peripheral blood stem cells in vitro Objective: Primary culture of CD34 positive stem cells collected from human peripheral blood was performed with and without supplementation with concentrated ascitic fluid; morphological and immunocytochemical pictures of cultured cells were taken chronologically and compared. Methods: CD34-positive stem cells collected from peripheral blood were cultured for 1, 24 and 48 hours. Concentrated ascitic fluid was added to the plates for the 24-and 48-hour cultures. For immunocytochemical studies, CD34, AE1/AE3, Ber-Ep4 (EA), EMA, EGFR, CD31, CA125 and D2-40 monoclonal antibodies were used. Results: After culture, small round cells with naked nuclei began to enlarge and to exhibit various changes in the cytoplasm and nucleus. Supplementation with concentrated body cavity fluid enhanced these changes. CD34-positive cells with small round cell features were detected 1 hour after culture and these had no epithelial or mesothelial markers. After 24 hours, CD34-positive cells had disappeared and cells weakly positive for EGFR, EMA, CA125 and D2-40 were detected. Cells with strong and moderate positive reactions for EGFR, AE1/AE3, EA, EMA, D2-40 and CA125 were detected after 48 hours. Supplementation with concentrated body cavity fluid increased the intensity and number of positive cells for these markers compared with the control group. The positive reaction, not only for the epithelial markers such as EGFR and AE1/AE3, but also for mesothelial markers such as CA125 and D2-40, was found to be increased in small numbers of cells in direct proportion to the duration of the primary culture of the peripheral blood cells. CD31, characteristically expressed in endothelial cells, was negative in the cultured cells. Conclusion: Supplementation of peripheral blood CD34-positive stem cells with body cavity fluid in vitro enhanced their differentiation toward cells of an epithelial or mesothelial phenotype, concomitant with loss of immunoreactivity for CD34. It is assumed that the routine cytological observation of cells obtained from body cavity fluid might cause possible cytomorphological and immunophenotypical changes due to the action of the growth factors contained in the body cavity fluid.