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Masaru Kojima

Publications and source records attributed to Masaru Kojima.

At least 37 records · Page 2Linked to original sources
PubMed2005

Usefulness of immunohistochemistry for recognizing metastatic colorectal adenocarcinoma in infarcted lymph nodes.

Lymph node infarction is a spontaneous coagulative necrosis of the affected lymph node and is frequently associated with concurrent and subsequent malignant lymphoma. However, this phenomenon appears to be rarely associated with metastatic carcinomas. Here, we report on the histopathologic and immunohistologic findings of three cases showing lymph node infarction in the regional lymph node associated with metastatic colorectal adenocarcinoma. Histologically, coagulative necrosis of metastatic carcinoma was surrounded by a thick rim of granuloma consisting of histiocytes with or without epithelioid features, foamy cells, and a small number of lymphocytes. The immunohistochemical study of the coagulative necrosis demonstrated that cytokeratins (AEI/AE3 and CAM5.2) and carcinoembryonic antigen (CEA) were well preserved in all three cases. However, compared with viable tumor tissues, only a few tumor cells were positive for epithelial membrane antigen. Using formalin-fixed and paraffin-embedded tissues, immunostaining for cytokeratins and CEA of the lymph node containing necrotic carcinoma may provide clinically valuable information.

Adenocarcinoma↗
PubMed2005

Idiopathic multicentric Castleman's disease. A clinicopathologic and immunohistochemical study of five cases.

Several lymphoproliferative disorders may be interpreted as multicentric Castleman's disease (MCD) clinicopathologically. These include HIV infection, autoimmune-disease-associated lymphadenopathy, idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia, "idiopathic MCD", POEMS syndrome (polyneuropathy, anasarca, organomegaly, endocrinopathy, M-proteins, and skin lesions), and non-Hodgkin's lymphomas. Among these, idiopathic MCD appears to be relatively rare. We report on the clinicopathologic and immunohistologic findings of five cases of idiopathic MCD and discuss the problems regarding their differential diagnosis. Some of the characteristic clinical findings of POEMS syndrome, including hepatosplenomegaly, skin change, endocrine abnormalities and anasarca, were present in all five cases. However, during the course of disease, minimal diagnostic criteria for POEMS syndrome, i.e., monoclonal plasma cell proliferation and sensory motor neuropathys, were absent in all five cases. The serum interleukin-6 level and the vascular endothelial growth factor level were found to be elevated in two of the cases examined. Various autoantibodies were detected in three cases. However, none of them fulfilled the diagnostic criteria for any of the definite autoimmune-disease. Histologically, three lesions exhibited a mixed type of Castleman's disease, and two exhibited the hyaline-vascular type. The majority of the germinal centers were of the hyaline-vascular or epithelioid germinal type, with a few hyperplastic germinal centers. The interfollicular area was characterized by prominent vascularity. Moderate to large sheets of plasma cells were observed in three mixed type cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. Immunohistochemical study demonstrated that the majority of germinal centers exhibited a tight/concentric pattern of FDC network. Few CD57-positive T-cells were observed in the hyaline-vascular and epithelioid follicles. The lack of CD57-positive T-cells appears to be related to the formation of abnormal germinal centers in the MCD.

Aged↗
PubMed2005

Atypical lymphoplasmacytic and immunoblastic proliferation from systemic lupus erythematosus. A case report.

A case of atypical lymphoplasmacytic and immunoblastic proliferation (ALPIBP) in the lymph nodes associated with well-documented systemic lupus erythematosus (SLE) is presented. A 30-year-old Japanese female with an 18-year history of SLE presented with right neck lymphadenopathy of 3 months duration. A biopsy specimen showed a diffuse effaced lymph node architecture without follicles and minimal sinuses. At high power field, a polymorphous population of small- to medium-sized lymphocytes, plasma cells, plasmacytoid cells, as well as large, basophilic transformed lymphocytes and immunoblasts diffusely infiltrated the paracortical area. Interestingly, the immunohistochemical study demonstrated large, irregularly shaped accumulations of follicular dendritic cells (FDCs) surrounding the small vessels, which is an immunohistochemical finding characteristic of angioimmunoblastic T-cell lymphoma (AILT). However, the present lesion showed the following differences to AILT: (a) absence of CD3+, CD4+ and CD10+ clear cells, which are tumor cells of AILT; (b) absence of pronounced arborizing vascular proliferation; (c) on molecular analysis, the present case demonstrated a polyclonal pattern converse to the monoclonal T-cell receptor gamma chain gene rearrangement in most AILTs (d) absence of EBV infected lymphoid cells, which are frequently detected AILT. As previously suggested, the present case indicates that a clinical correlation as well as immunohistologic and genotypic studies may be necessary to discriminate between ALPIBPs and AILT.

Adult↗
PubMed2005

Idiopathic ulcer of the small bowel containing numerous plasma cells: case resembling mucosa-associated lymphoid tissue lymphoma.

Idiopathic ulcer of the small bowel is a poorly recognized entity. Herein is reported a case of idiopathic ulcer of the jejunum containing numerous lymphoplasmacytoid infiltrates and mimicking mucosa-associated lymphoid tissue (MALT) lymphoma. An 82-year-old Japanese woman presented with nausea and vomiting. Following diagnosis of submucosal tumor, partial jejunal resection was performed. Macroscopically the resected specimen contained multiple small shallow ulcers. Histologically the lesion was composed of numerous plasma cells mixed with lymphocytes and histiocytes. Immunohistological study revealed that the plasma cells contained polytypic intracytoplasmic immunoglobulins. The patient remained free of disease after 36 months. Marginal zone B-cell lymphoma of MALT-type arising from small intestine occasionally shows prominent plasma cell differentiation. The present case demonstrates that idiopathic ulcer of the small bowel should be added to the differential diagnosis of MALT-type lymphoma of the small bowel.

Aged↗
PubMed2005

Lymphoid variant of hyaline vascular Castleman's disease containing numerous mantle zone lymphocytes with clear cytoplasm.

We report two unusual cases of hyaline vascular type Castleman's disease showing a pale clear cuff of mantle zone lymphocytes presenting a marginal zone distribution pattern. These cells had medium-sized round or slightly indented nuclei and a moderate amount of clear cytoplasm. The histopathologic findings in our cases were similar to those of nodal marginal zone B-cell lymphoma. However, immunohistochemistry demonstrated that both the mantle zone lymphocytes and the pale cuff of the lymphoid cells were CD20+, CD79a+, sIgM+, sIgD+, CD5-, CD10-, CD43-, CD45RO-, Bcl-2+, Bcl-6- and cyclin D1-. The polytypic nature of these cells was demonstrated by immunohistochemistry and polymerase chain reaction. Reactive lymph node lesions only rarely show mantle cell hyperplasia with clear cytoplasm. This unusual mantle cell hyperplasia with clear cytoplasm associated with a hyaline vascular type of Castleman's disease should be differentiated from nodal marginal zone B-cell lymphoma, mantle cell lymphoma and follicular lymphoma. To avoid overdiagnosis and overtreatment, it is suggested that immunophenotypic and genotypic studies might be required, and furthermore careful attention should be paid to the morphologic examination.

Adult↗
PubMed2005

Follicular lymphoid hyperplasia of the oral cavity representing progressive transformation of germinal center.

Follicular lymphoid hyperplasia (FLH) of the oral cavity is a rare and poorly understood lymphoproliferative disorder. We present a case of FLH of the oral cavity presenting with progressive transformation of germinal center (PTGC). The patient was a 49-year-old Japanese woman presenting with a hard mass in the right cheek. The resected specimen contained numerous lymphoid follicles with active germinal centers and a portion of the lymphoid follicles exhibited PTGC. The PTGCs contained a few large lymphoid cells resembling lymphocytic and histiocytic Reed-Sternberg cells of nodular lymphocyte-predominant Hodgkin lymphoma. The PTGC was surrounded by groups of epithelioid cells. In situ hybridization studies demonstrated strong expression of Epstein-Barr virus (EBV)-encoded small RNA in scattered large lymphoid cells in the PTGC. Although the etiology of FLH of the oral cavity remains unclear, the present case suggests that a subset of FLH of the oral cavity appears to be an EBV-associated lymphoproliferative disorder.

Cell Proliferation↗
PubMed2005

Progressive transformation of germinal center presenting with histological features of hyaline-vascular type of Castleman's disease.

We report three cases showing progressive transformation of the germinal center (PTGC) with histological features reminiscent of the hyaline-vascular (HV) variant of Castleman's disease (CD). Each case contained a few small HV germinal centers as well as PTGC and hyperplastic germinal centers with or without follicular lysis. Moreover, some of the PTGC were penetrated by hyalinized small vessels. Our three cases also showed some of the characteristic histological findings of HV type of CD: (i) reactive lymphoid follicles with small hyaline-vascular germinal centers surrounded by small lymphocytes in a concentrated fashion; (ii) a few small foci of plasmacytoid monocytes; (iii) perivascular fibrosis; (iv) interfollicular vascularity; (v) tight/concentric pattern of the follicular dendritic cell network; and (vi) absence of CD57+ T-cells in the HV follicles. The PTGC with coexistent HV type of CD may represent a certain form of reactive follicular hyperplasia. The possibility of PTGC should be considered and excluded before diagnosing CD.

Adult↗
PubMed2005

Follicular colonization of nodal marginal-zone B-cell lymphoma resembling follicular lymphoma: report of 6 cases.

The formation of neoplastic B-cell follicles is accepted as a diagnostic criterion of follicular lymphoma. However, extranodal marginal-zone B-cell lymphomas (MZBLs) of mucosa-associated lymphoid tissue (MALT) type also sometimes contain numerous lymphoid follicles and may even have a predominantly follicular growth pattern. However, morphologic, immunohistochemical, and genotypic findings suggest that lymphoid follicles in extranodal MZBLs are neoplastic follicles formed as the result of colonization of previously reactive follicles by tumor cells (centrocyte-like cells). We present here 6 cases of nodal MZBL demonstrating a follicular growth pattern. Immunohistochemical study demonstrated that the tumor cells were CD10-, CD20+, CD79a+,CD138-, Bcl-2+, Bcl-6- and IRF4+. Residual nonneoplastic follicular center cells were CD10+, CD20+, CD79a+, Bcl-2-, and Bcl-6+. CD21/CD23 immunostain demonstrated a disrupted follicular dendritic cell pattern characteristic of follicular colonization in extranodal MZBL of MALT type. Taken in conjunction with the morphologic findings, nodal MZBL may also show a follicular growth pattern similar to extranodal MZBL of MALT type. The marginal-zone nature is most recognizable on immunohistochemistry, although the histologic appearance alone may cause some diagnostic problems. It is important for pathologists to consider this type of lesion in diagnostic practice.

Adult↗
PubMed2005

Clinical implication of florid reactive follicular hyperplasia in Japanese patients 60 years or older: a study of 46 cases.

Florid reactive follicular hyperplasia (FRFH) of the enlarged lymph node in middle-aged or elderly patients requiring biopsy is a relatively uncommon phenomenon as compared with that in younger age groups. Between 1984 and January 2004, we encountered 46 patients, aged 60 years or older, in whom histology of biopsied lymph node specimens showed inappropriate FRFH for the patient's age. An apparent cause of lymphadenopathy was initially identified in 17 cases (37%): 11 with autoimmune disease and related disorders, 3 with cancer-reactive lymphadenopathy, 2 with Epstein-Barr virus-associated lymph node lesion exhibiting transient autoimmune-disease-like clinical findings, and 1 with atypical mycobacterial infection. Among 29 patients without specific etiology, 16 patients (55%) exhibited histologic findings of progressive transformed germinal center (PTGC). Only 1 of our patients developed malignant lymphoma during the follow-up period. The present study indicates that PTGC is included in the etiology of FRFH in elderly Japanese patients as well as imbalance of the immune system such as autoimmune-disease-associated lymphadenopathy and idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia. By in situ hybridization, Epstein-Barr virus genomes were demonstrated in only 6 (15%) of 39 cases examined.

Aged↗
PubMed2005

Reactive lymphoid hyperplasia of the lymph nodes with giant follicles: a clinicopathologic study of 14 Japanese cases, with special reference to Epstein-Barr virus infection.

To clarify the clinicopathologic and immunohistochemical features of reactive lymphoid hyperplasia with giant follicles (RHGF) among Japanese, 14 patients were studied. The subjects consisted of 9 males and 5 females, ranging in age from 9 to 61 years, with a mean age of 30 years and a median age of 24 years. None of the patients exhibited systemic symptoms. The affected lymph nodes were located in the head and neck area except in 1 case. At the time of lymph node biopsy, 1 patient was diagnosed as having acute infectious mononucleosis (IM) and 2 patients had a recent history of acute IM. One each with myelogenous leukemia or diffuse large B-cell lymphoma had a history of peripheral blood stem cell transplantation. There were no recurrences during follow-up periods ranging from 3 to 50 months. Histologically, 14 lesions were characterized by numerous enlarged, coalescing lymphoid follicles with distortion rather than effacement of the lymph node architecture. By in situ hybridization, Epstein-Barr virus (EBV) genomes were demonstrated in 5 (36%) of 14 cases. The present study indicates that a portion of RHGF appears to represent a histologic finding of acute IM. Moreover, as previously stated, RHGF should be differentiated from follicular lymphoma, particularly the floral variant.

Adolescent↗
PubMed2005

Distribution of Epstein-Barr virus in systemic rheumatic disease (rheumatoid arthritis, systemic lupus erythematosus, dermatomyositis) with associated lymphadenopathy: a study of 49 cases.

Among systemic rheumatic diseases (SRDs), lymphadenopathy is frequently found in patients with rheumatoid arthritis (RA) and systemic lupus erythematous (SLE). Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPDs) may occur in patients following methotrexate therapy for RA and dermatomyositis (DM). However, little is known about the distribution of EBV in reactive LPDs in patients with SRDs who had no history of methotrexate therapy. We analyzed 49 such patients (SLE=25, RA=23, DM=1) for the presence and distribution of EBV+ cells using Epstein-Barr virus (EBV)-encoded small RNA (EBER) specific in situ hybridization. A positive signal for EBERs was identified in 9 (SLE=5, RA=4) (18%) of 49 cases, and 3 main distribution patterns of EBER+cells could be delineated: pattern A, more than 500 EBER-positive cells were located in the germinal centers as well as interfollicular area (SLE=2); pattern B, EBER + cells were located in a few germinal centers (RA=2); and pattern C, up to 100 EBER+ cells were located in the interfollicular area (SLE=3, RA=2). Recent EBV infection may be a cause of lymph node lesion in only 2 cases of patients with pattern A. However, the pathognomonic significance of pattern B and pattern C EBER + cell distribution patterns still remains unclear. Our study indicates that the underlying immune deficits of patients with SRDs may also play an important role in the development of EBV-associated LPDs in SRDs, as previously suggested by several authors.

Adult↗
PubMed2004

Rectal cancer associated with chronic lymphocytic leukemia.

It has been reported that chronic lymphocytic leukemia (CLL) often occurs concomitantly with other malignant neoplasms. However, because CLL is rare in Japan, there are only a limited number of reports of the occurrence of malignant neoplasia in Japanese patients with CLL. We report here the simultaneous occurrence of rectal cancer and CLL in a 57-year-old man. Because the clinical stage of CLL was Rai system I, we decided, in accordance with the National Cancer Institute-Sponsored Working Group guidelines, to monitor him without therapy for CLL until evidence of disease progression, and we performed abdominoperineal resection of the rectum for the cancer. The small rectal tumor was associated with aggressive lymphangiosis carcinomatosa, and multiple nodal metastases were observed in the pool of CLL cells. He died of rectal cancer 7 months after the operation, and autopsy revealed extensive metastases of the cancer. Cellular and humoral immunity is often impaired in patients with CLL, and the defective immunity in this patient may have had an etiological role in the development and rapid progression of the cancer. In the follow-up of CLL patients, we must always be aware of the possible existence of a second malignant disease. Particular attention should be paid to those with defective immunity, and screening should be performed, especially for pulmonary and gastrointestinal malignancies.

Colonoscopy↗
PubMed2004

Atypical lymphocytosis resembling non-Hodgkin's lymphoma in peritoneal effusion of infectious mononucleosis: a case report.

Peritoneal effusion appears to be an unusual complication of infectious mononucleosis (IM). The cytological features of peritoneal effusion from a patient affected by IM are presented. The patient was a 21-year-old Japanese woman, with typical and physical findings of IM. Ascites disappeared with resolution of acute IM. The cytospin smears of the ascitic fluid were highly cellular, consisting exclusively of lymphoid cells. Lymphoid cells were composed of large cells with broad basophilic cytoplasm, as well as of small to medium-sized cells having scant cytoplasm and irregularly shaped nuclei. The overall cytomorphological pictures posed serious difficulties in differentiating this condition from those of peripheral T-cell lymphomas manifesting ascites. The majority of atypical lymphocytes, including large cells, expressed CD3 and CD8. The present case indicates that IM should be added to the list of lesions considered for the differential diagnosis of non-Hodgkin's lymphoma of the peritoneal fluid, particularly regarding young adults.

Adult↗
PubMed2004

Lymph node lesion in infectious mononucleosis showing geographic necrosis containing cytologically atypically B-cells. A case report.

Lymph node lesions in infectious mononucleosis (IM) show a marked histological diversity and may occasionally be confused with malignant lymphoma. We report on a rare case of IM showing geographic lymph node necrosis as well as angiocentric lymphoproliferative lesions, and containing numerous centroblasts, immunoblasts and Reed-Sternberg (RS)-like cells. The patient was a 40-year-old Japanese man with signs and symptoms of classical IM. This was later confirmed serologically, but the necrotic area comprised 50% of a cervical lymph node. The large lymphoid cells, including RS-like cells, were CD3-, CD5-, CD15-, CD20+, CD30+, CD45RO-, CD79a+, LMPI+, and EBNA2+. In situ hybridization study also disclosed that these cells were associated with Epstein-Barr virus (EBV). The patient was disease free during a follow-up of 15 years. Although the classical IM syndrome rarely shows a close resemblance to lymphomatoid granulomatosis of the lymph node or to EBV+ B- cell lymphoproliferative disorders associated with an immunodeficient state on histology, it is important for pathologists to be aware of this type of lesion in diagnostic practice.

Antigens, CD↗
PubMed2004

Hepatic angiomyolipoma resembling an inflammatory pseudotumor of the liver. A case report.

Hepatic angiomyolipoma (AML) may demonstrate a marked histologic diversity and is frequently misdiagnosed. HMB45 is a promising marker for this tumor and is expected to facilitate the recognition of some AMLs with unusual morphology. We report on a case of hepatic AML exhibiting histologic features that were similar to inflammatory pseudotumor (IPT) or to IPT-like follicular dendritic cell (FDC) tumor of the liver. The patient was a 21-year-old Japanese woman with a mass in the left lobe of the liver (70 x 73 mm). There were no clinical features of tuberous sclerosis. Histologically, numerous inflammatory cells, including small lymphocytes, plasma cells, and histiocytes, showed diffuse infiltration throughout the lesion. However, the present case also shared some of the morphologic findings of hepatic AML, including clusters of smooth muscle cells with clear cytoplasm, a few scattered adipose cells, and thick-walled blood vessels. Moreover, the smooth muscle cells consisted of spindle-shaped cells or larger, more rounded cells with either clear cytoplasm or eosinophilic epithelioid cell features positive for vimentin, muscle-specific actin, and smooth muscle actin. HMB45 immunostaining confirmed the diagnosis of AML. The present case indicates that IPT or IPT-like FDC tumor should be added to the list of differential diagnoses for AML of the liver.

Adult↗
PubMed2004

Multimeric structure of the PomA/PomB channel complex in the Na+-driven flagellar motor of Vibrio alginolyticus.

It is known that PomA and PomB form a complex that functions as a Na(+) channel and generates the torque of the Na(+)-driven flagellar motor of Vibrio alginolyticus. It has been suggested that PomA works as a dimer and that the PomA/PomB complex is composed of four PomA and two PomB molecules. PomA does not have any Cys residues and PomB has three Cys residues. Therefore, a mutant PomB (PomB(cl)) whose three Cys residues were replaced by Ala was constructed and found to be motile as well. We carried out gel filtration analysis and examined the effect of cross-linking between the Cys residues of PomB on the formation of the PomA/PomB complex. In the presence of dithiothreitol (DTT), the elution profile of the PomA/PomB complex was shifted to a lower apparent molecular mass fraction similar to that of the complex of the wild-type PomA and PomB(cl) mutant. Next, to analyze the arrangement of PomA molecules in the complex, we introduced the mutation P172C, which has been shown to cross-link PomA molecules, into tandem PomA dimers (PomA approximately PomA). These mutant dimers showed a dominant-negative effect. DTT could restore the function of PomA approximately P172C and P172C approximately P172C, but not P172C approximately PomA. Interdimer and intradimer cross-linked products were observed; the interdimer cross-linked products could be assembled with PomB. The formation of the interdimer cross-link suggests that the channel complex of the Na(+)-driven flagellar motor is composed of two units of a complex consisting of two PomA and one PomB, and that they might interact with each other via not only PomA but also PomB.

Amino Acid Sequence↗
PubMed2004

The role of radiotherapy for thymic carcinoma.

OBJECTIVE: The aim of this study is to evaluate retrospectively the role of radiotherapy for thymic carcinoma. METHODS: Between 1973 and 1998, 14 patients with thymic carcinoma were treated at Gunma Prefectural Cancer Center. Two patients who had hematogenous metastasis were excluded from this study, therefore 12 patients were analyzed. The Masaoka staging system was used; four patients were diagnosed with stage III disease and eight patients with stage IV disease. The pathological subtype according to the World Health Organization histological criteria for thymic tumors was squamous cell carcinoma (low-grade histology) in six cases and undifferentiated carcinoma (high-grade histology) in six. Ten patients underwent thoracotomy, and two patients underwent excisional biopsy without thoracotomy. Ten patients (83%) received radiotherapy as a curative intent, and the median dose was 60 Gy. Systemic chemotherapy was administered to four patients (33%), and the majority (75%) of the regimens contained cisplatin. RESULTS: The 3-year overall survival rate was 25%. Histological subtype (low-grade versus high-grade), surgical resection (complete versus incomplete), radiotherapy and chemotherapy were evaluated as prognostic factors in a univariate analysis. Low-grade histology and complete resection were good prognostic factors, although these were not statistically significant. Patients who received radiotherapy had a better outcome than those who did not. The major sites of recurrence were the pleura and pericardium. Recurrence within the radiation field was observed in one of seven patients in whom failure patterns could be evaluated. CONCLUSION: Complete resection is mandatory if possible. Radiotherapy plays an important role in treating thymic carcinoma in terms of reducing local recurrence and prolonging survival time. Establishment of an innovative treatment protocol that includes chemotherapy is necessary to control intrathoracic relapse and distant metastasis.

Adult↗