Multiple small tumor formation on both surfaces of the aortic valve cusps in Epstein-Barr virus-associated T/NK-cell lymphoproliferative disease: a case report.

A 41-year-old woman presented acute cerebral infarction. Transesophageal echocardiography revealed multiple masses only on both surfaces of the aortic valve cusps. There was no primary lesion outside the heart according to various examinations. After treatment for cerebral infarction, we replaced the aortic valve instead of preservation because the intraoperative histological examination reported that malignancy was highly suspected. Contrary to the rapid frozen section diagnosis, histological and immunohistochemical examinations failed to exhibit malignancy. The tumors were composed of atypical large lymphoid cells and they were assessed to be related to T-/natural killer-cells. Furthermore, Epstein-Barr virus related markers were also positive. Her three-year postoperative course was uneventful without chemotherapy. We report an extremely rare case of Epstein-Barr virus-associated T-/natural killer-cell lymphoproliferative disease which formed multiple small tumors on both surfaces of the aortic valve.

A case of familial amyloid polyneuropathy (FAP ATTR Ile107Val) with proximal muscle weakness in the lower extremities.

Proximal dominant muscle weakness is rare in transthyretin (TTR)-related familial amyloid polyneuropathy (FAP). A 69-year-old Japanese man developed numbness and dysesthesia of the first, second and third digits of both hands since 2008. He presented to our hospital with one year history of progressive proximal muscle weakness in the lower extremities since 2013. Neurological examinations revealed predominant proximal muscle weakness and atrophy with areflexia in the lower extremities, decreased superficial sensation in the first, second and third fingers of both hands, and decreased superficial and deep sensation in the lower extremities. Nerve conduction studies revealed an axonal degeneration type of sensorimotor polyneuropathy and bilateral carpal tunnel syndrome. Electromyogram revealed acute and chronic neurogenic changes predominantly in proximal muscles. We performed biopsy of the left quadriceps muscle and observed neurogenic changes in the muscle tissue and an amyloid deposition in the adipose tissue. This amyloid deposition was not seen in endomysium, perimysium and blood vessels. Genetic analysis of the TTR gene revealed the patient was heterozygous for a single nucleotide substitution c.379 A>G, which resulted in the replacement of valine with isoleucine at position 107 of the mature protein. We diagnosed his condition as FAP with Amyloid Transthyretin (ATTR) Ile107Val.

Early Stages of Hyaline Membrane Formation Detected in Alveolar Mouths in Diffuse Alveolar-Damage-Associated Diseases: A Detailed Immunohistochemical Study.

To study the early stages of hyaline membrane (HM) formation, diffuse alveolar damage (DAD) was thoroughly investigated using immunohistochemical methods in 15 autopsy cases, which consisted of various types of interstitial pneumonias and pulmonary diseases derived from nonmalignant or malignant diseases. Alveolar mouths (AMs) that were presumed to be normal were ultrastructurally examined in detail, by using pulmonary tissues in the pneumothorax. It is interesting to note that during the initial stages of HM formation in AMs, fragmented eosinophilic masses were closely attached to AMs as irregular fragments or by a cap-like structure. The ultrastructure revealed some distance between the capillary spaces and surface epithelium of the AMs, indicating that the epithelial cells at the AMs might be often easily damaged even by minor stimuli; they can be considered as "locus minoris resistentiae." HMs were found to be formed initially at the site of AMs derived from fragmented eosinophilic masses in not only pulmonary but also extrapulmonary diseases, including both nonmalignant and malignant diseases. These irregular eosinophilic masses, representing the early shape of HMs, were immunohistochemically positive for the epithelial membrane antigens, namely, surfactant protein A and factor VIII antigen, and occasionally for KL-6 and cytokeratins. These results suggested that fragmented irregular masses represent the initial phase of HM formation. Five of 15 cases were focally negative for KL-6 at the initial irregular mass of HMs. Because KL-6 is one of the fundamental components of pulmonary surface elements, it needs to be studied further by detailed clinicopathological examination.

Investigation of aluminum and iron deposition on metaplastic bones in three patients with diffuse pulmonary ossification.

Diffuse pulmonary ossification (DPO) is a rare pulmonary lesion. DPO is typically detected at autopsy rather than premortem. Recently, however, several cases were diagnosed antemortem using computed tomography, high-resolution computed tomography, or video-assisted thoracic surgery. In the present study, we evaluated DPO at autopsy from two patients with post-myocardial infarction (cases 1 and 3) and one patient with duodenal cancer (case 2). Multiple metaplastic bones (nodular in case 1 and 3 or dendriform in case 2) were detected in these three cases. In an attempt to detect aluminum and iron deposition in these metaplastic bones, histochemical investigations were performed. The two nodular types of one and three cases were positive for aluminum and iron, but the dendriform type of case 2 was positive only for aluminum. The depositions occurred in a linear pattern along the calcifying front. It is of great interest that these deposition patterns were similar to those of bones from three previously reported DPO cases and from the bones of hemodialysis patients. It is suggested that these abnormal metal depositions in the calcifying front might disturb the normal mineralization processes of the metaplastic bones, although no morphological abnormality was detected, except for dense black color of calcifying front lines. Further investigations are needed in more patients with DPO to obtain more information on this topic.

Vasculo-smooth muscle hamartomatous structure is linked to morphogenesis of colorectal polypoid adenoma.

To investigate the difference of surrounding stromal structure between the polypoid and flat adenomas in the colorectum, we performed microscopic study including immunohistochemistry in a total of 32 colorectal adenomas (typical 24 polypoid and eight flat adenomas), especially focusing on vessels around muscularis mucosa. All 24 polypoid adenomas accompanied vasculo-smooth muscle hamartomatous structure in association with muscularis mucosa and submucosal vessels, whereas none of eight flat adenomas had vasculo-smooth muscle hamartomatous structure; surrounding muscularis mucosa and submucosa of the flat adenomas are identical to those of normal colorectal tissue. Vasculo-smooth muscle hamartomatous structure is linked to the morphogenesis of colorectal polypoid adenomas.

Disappearance of GFP-positive hepatocytes transplanted into the liver of syngeneic wild-type rats pretreated with retrorsine.

BACKGROUND AND AIM: Green fluorescent protein (GFP) is a widely used molecular tag to trace transplanted cells in rodent liver injury models. The differing results from various previously reported studies using GFP could be attributed to the immunogenicity of GFP. METHODS: Hepatocytes were obtained from GFP-expressing transgenic (Tg) Lewis rats and were transplanted into the livers of wild-type Lewis rats after they had undergone a partial hepatectomy. The proliferation of endogenous hepatocytes in recipient rats was inhibited by pretreatment with retrorsine to enhance the proliferation of the transplanted hepatocytes. Transplantation of wild-type hepatocytes into GFP-Tg rat liver was also performed for comparison. RESULTS: All biopsy specimens taken seven days after transplantation showed engraftment of transplanted hepatocytes, with the numbers of transplanted hepatocytes increasing until day 14. GFP-positive hepatocytes in wild-type rat livers were decreased by day 28 and could not be detected on day 42, whereas the number of wild-type hepatocytes steadily increased in GFP-Tg rat liver. Histological examination showed degenerative change of GFP-positive hepatocytes and the accumulation of infiltrating cells on day 28. PCR analysis for the GFP transgene suggested that transplanted hepatocytes were eliminated rather than being retained along with the loss of GFP expression. Both modification of the immunological response using tacrolimus and bone marrow transplantation prolonged the survival of GFP-positive hepatocytes. In contrast, host immunization with GFP-positive hepatocytes led to complete loss of GFP-positive hepatocytes by day 14. CONCLUSION: GFP-positive hepatocytes isolated from GFP-Tg Lewis rats did not survive long term in the livers of retrorsine-pretreated wild-type Lewis rats. The mechanism underlying this phenomenon most likely involves an immunological reaction against GFP. The influence of GFP immunogenicity on cell transplantation models should be considered in planning in vivo experiments using GFP and in interpreting their results.

[A case of adult-onset type II citrullinemia in an elderly patient].

A 72-year-old man presented with consciousness disturbance. The results of brain magnetic resonance imaging and cerebrospinal fluid examination were normal, but triphasic waves were noted on electroencephalography. His plasma ammonia level was elevated due to which encephalopathy secondary to hyperammonemia was suspected. However, his liver function was normal, and no evidence of cirrhosis or portal-systemic shunt was noted. The patient's medical history revealed that he had a tendency to excessively consume pulse products since childhood, and an amino acid analysis showed elevation of citrulline and arginine levels. Thus, we diagnosed the patient with an extremely rare case of adult-onset type II citrullinemia, which was triggered by cessation of the intake of pulse foods (soybeans and peanuts) due to dental problems.

Expression of podoplanin/D2-40 in pericryptal stromal cells in superficial colorectal epithelial neoplasia.

The aim of this study is to investigate the distribution and roles of podoplanin/D2-40-positive pericryptal stromal cells in superficial colorectal epithelial neoplasia. A total of 105 superficial colorectal epithelial tumors were examined: 65 tubular/tubulovillous adenomas, 32 adenocarcinomas in situ, and 8 submucosally invasive adenocarcinomas. Immunohistochemical analysis was performed using the monoclonal antibody to podoplanin/clone D2-40, which is reactive in both lymphatic endothelial cells and activated stromal cells, but negative in vascular endothelial cells. We found 50 (78 %) of 65 tubular/tubulovillous adenomas, 30 (94 %) of 32 adenocarcinomas in situ, and all 8 (100 %) submucosally invasive adenocarcinomas had podoplanin/D2-40-positive pericryptal stromal cells, whereas all normal colorectal mucosae had no podoplanin/D2-40-positive pericryptal stromal cells. The presence of podoplanin/D2-40-positive pericryptal stromal cells is associated with epithelial tumorigenesis in the colorectum.

[Effects of mast cells on degradation of collagen fibers in dimethylnitrosamine-induced hepatic fibrosis of rat].

OBJECTIVE: To investigate the relationship between mast cell and hepatic fibrosis by histopathological method and semi-quantitative measurement. METHODS: Seventy-two Wistary male rats, the control group and the normal group of each only 16, experimental group of 40 rat liver fibrosis was induced by injection of DMN and was sampled at eight different time points. HE, histochemistry, immunohistochemistry (ABC method) and immunofluorescence were performed. The size of fibrosis and the number of mast cells were counted. The expression of MMP-2 and TIMP-2 was documented and electron microscopic examination was performed. RESULTS: After injection of DMN, the fibrosis was the most severe in the 2 week (3.72%) and the first month (3.73%, P = 0.2626), and then gradually diminished, although residual fibrosis was still present at 12 months (1.42%, P = 0.0003). The appearance of mast cells began at 2 weeks (1.73 per 200 power field in average by light microscope) after the injection and reached the peak at 4 months (3.06, P = 0.008). Residual amount of mast cells were present at 12 months (1.04, P = 0.045). However, the degree of fibrosis was not proportional or overlapping with the number of mast cells in this experiment model. Mast cells expressed MMP-2 but not TIMP-2. CONCLUSIONS: In the DMN-induced rat liver fibrosis model, mast cell may be an integral player in the pathogenesis of liver fibrosis and may contribute to the degradation of fibrosis by synthesizing and secreting MMP-2.

[Solitary actinomycotic brain abscess: case report].

Actinomycotic brain abscess is a rare condition with uncertain clinical features. Here we report the case of a 66-year-old immune-competent woman with an actinomycotic brain abscess who presented with sensory aphasia and mild right hemiparesis. She had no febrile episode or headache. Moreover, she did not have any periodontal or oto-rhino-laryngological disease, and the results of laboratory tests were normal. A computed tomography scan showed an irregular, low-density area in the left parietal lobe. Subsequent magnetic resonance imaging showed low-signal intensity in a T1 weighted image, high-signal intensity in a T2 weighted image, and mixed intensity on a diffusion weighted image. Thallium-201 chloride scintigraphy showed definite accumulation of thallium in the lesion and the patient's condition gradually deteriorated. Ten days after gadolinium administration, a T1 weighted image showed a multi- lobulated irregular mass in the left parietal lobe. The patient subsequently underwent craniotomy and evacuation of the yellowish abscess. Gram staining of the tissue showed the presence of gram-positive filamentous rods, and abscess cultures were positive for Actinomyces and Prevotella disiens. The abscess resolved after treatment with a high dose of intravenous penicillin G (24 million units/day) for 8 weeks, followed by an oral dose of amoxicillin for 4 months. The patient was discharged with a rudimentary limitation of the visual field.

Neutrophil infiltration and oxidant-production in human atherosclerotic carotid plaques.

To clarify the clinical implications of neutrophils in vulnerable plaques we evaluated the function and activity of infiltrated neutrophils in an atherosclerotic plaque, focusing on oxidant production. A histopathological investigation was performed using carotid arterial samples obtained from seven patients. The atherosclerotic plaques were examined cytochemically for naphthol-ASD-chloroacetate esterase activity and oxidant-production, and immunohistochemically using N-formyl peptide receptor-like 1 (fPRL1)-, CD66b-, CD68- or p22phox-specific antibodies. The cytoplasmic fPRL1 intensity value of the neutrophils in the plaque was estimated using an activity index. Naphthol-ASD-chloroacetate esterase activity was found in cells located in the atherosclerotic plaque, indicating that the cells were neutrophils. The cytoplasmic fPRL1 intensity value of the neutrophils in the plaque decreased to approximately 60% of the intensity observed in the capillary vessels. Oxidant-production was also detected in the plaques, and both neutrophils and macrophages were observed at the corresponding oxidant-production sites. p22phox expression was also located in the same areas in which oxidant-production was observed in these plaques. We could not directly evaluate how much ROS generated from the infiltrated neutrophils contributed the plaque vulnerability followed by its rupture. However, the infiltrated neutrophils in the atherosclerotic plaques morphologically appeared activated and were actively generating oxidant, implying that neutrophils, together with macrophages, infiltrate into atherosclerotic plaques and contribute to plaque vulnerability.

Epstein-Barr virus-infected subcutaneous panniculitis-like T-cell lymphoma associated with methotrexate treatment.

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a lymphoid proliferation or lymphoma in patients treated with MTX. We report a case of Epstein-Barr virus (EBV)-positive subcutaneous panniculitis-like T-cell lymphoma (SPTCL) in a 60-year-old Japanese man treated with MTX for rheumatoid arthritis (RA). SPTCL is a rare cytotoxic T-cell lymphoma characterized by involvement of subcutaneous fat mimicking panniculitis. The patient, who had been on MTX therapy for RA, manifested high fever and lumbago. Physical examination showed multiple subcutaneous nodules on the trunk including axillary and inguinal regions. Biopsy of the inguinal nodule showed profuse infiltration of CD8(+) T-cell lymphoma cells in the subcutaneous adipose tissues. A diagnosis of SPTCL was made according to the diagnostic criteria of World Health Organization classification. EBV-encoded small RNA in situ hybridization revealed that the lymphoma cells contained EBV genome. The cells were positive for EBV latent membrane protein 1, but not for EBNA2. After discontinuation of MTX, the nodules regressed spontaneously. Studies have reported that most MTX-LPDs are B-cell type lymphomas and Hodgkin lymphoma. To the best of our knowledge, EBV-positive SPTCL has not been reported in patients receiving MTX. Our case emphasizes the importance of clinical and virological characterization of MTX-associated SPTCL.

Super paramagnetic iron oxide MRI shows defective Kupffer cell uptake function in non-alcoholic fatty liver disease.

BACKGROUND: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is incompletely understood. Kupffer cells (KCs), phagocytic liver-resident macrophages, provide a protective barrier against egress of endotoxin from the portal to the systemic circulation. It is not known if KC phagocytic function is impaired in NAFLD. Super-paramagnetic iron oxide (SPIO) magnetic resonance imaging is a comparative technology dependent on KC phagocytic function. OBJECTIVE: To evaluate KC uptake function, in patients and experimental animals with NAFLD, using SPIO. METHODS: Abdominal CT and histological examination of liver biopsy specimens were used to estimate the degree of steatosis in patients with NAFLD and controls with chronic hepatitis C. SPIO-MRI was then performed in all patients. Normal rats fed a methionine-choline-deficient diet to induce non-alcoholic steatohepatitis (NASH), the more severe stage of NAFLD, and obese, insulin resistant, Zucker fa/fa rats with steatohepatitis, were also studied with SPIO-MRI and analysed for hepatic uptake of fluorescent microbeads. Immunohistochemical analysis evaluated the numbers of KCs in patients and rat livers. RESULTS: Relative signal enhancement (RSE), inversely proportional to KC function, was higher in patients with NAFLD than in controls and with the degree of steatosis on CT. RSE also positively correlated with the degree of steatosis on histology and was similarly higher in rats with induced severe NAFLD (NASH). On immunohistochemistry, defective phagocytic function was the result of reduced phagocytic uptake and not due to reduced KC numbers in rats or patients with NAFLD. CONCLUSIONS: KC uptake function is significantly impaired in patients with NAFLD and experimental animals with NASH, worsens with the degree of steatosis and is not due to a reduction of KC numbers.

Lecithin: retinol acyltransferase protein is distributed in both hepatic stellate cells and endothelial cells of normal rodent and human liver.

BACKGROUND: To determine the extent to which hepatic stellate cell (HSC) activation contributes to liver fibrosis, it was found necessary to develop an alternative structural and functional stellate cell marker for in situ studies. Although several HSC markers have been reported, none of those are associated with particular HSC functions. AIM: The present study was undertaken to examine whether lecithin:retinol acyltransferase (LRAT), the physiological retinol esterification enzyme of the liver, is a potential and relevant tissue marker for HSC. METHODS: An antibody specific to mouse and human LRAT was prepared based on the amino acid sequences. Antibodies to LRAT were used for immunohistochemical studies to assess the distribution of LRAT-positive cells in the liver with the aid of fluorescence and immunogold electron microscopy. RESULTS: LRAT-positive cells were found to be confined in the space of Disse, corresponding with the location of desmin-positive HSC in rodent liver, also in human liver. Interestingly, LRAT-positive staining was also observed along the liver sinusoidal endothelial lining. Furthermore, immune electron microscopic studies revealed that LRAT was mainly distributed in HSC within the rough-endoplasmic reticulum (RER) and multivesicular bodies, whereas LRAT staining within the endothelial cells was largely confined to the perinuclear area and to some extent to the RER. CONCLUSION: Evidence has been accumulated that LRAT might serve as an excellent alternative HSC marker for future structural and functional studies. Furthermore, the presence of LRAT in endothelial cells might suggest a currently unknown function of this enzyme in liver endothelial biology.

Expression of fascin-1, an actin-bundling protein, in migrating hepatoblasts during rat liver development.

Fascin-1 is an actin-bundling protein localized at the core actin bundles within microvillar projections and filopodial extensions in migrating cells. It is expressed at a low level in normal epithelial cells, but at a high level in tumor cells, indicating its importance in the invasion and motility of tumor cells. In addition, fascin-1 is expressed in human and murine embryos, occurring at high levels especially in developing nervous tissues. In this study, we have investigated the expression patterns of fascin-1 immunohistochemically during the early stages of rat hepatogenesis. A high expression of fascin-1 was detected in the liver bud and hepatoblasts at embryonic day (ED) 10.5, ED11.5, and ED12.5. Expression fell by ED13.5 and was not detectable at ED14.5. These observations demonstrate that the expression of fascin-1 is correlated with the migration activity of hepatoblasts during the early stages of liver development in rats.

Distribution and role of myofibroblasts in human normal seminal vesicle stroma.

We studied the distribution of myofibroblasts in the stroma of normal seminal vesicles. Twelve normal seminal vesicles obtained by surgery on the diagnosis of some diseases were selected, and we evaluated the distribution of myofibroblasts in the seminal vesicles using immunohistochemical and electron and immunoelectron microscopic techniques. Immunohistochemically, myofibroblasts, which were positive for alpha-smooth muscle actin (ASMA) and negative for high molecular weight caldesmon (h-CD), were observed in the stroma just beneath the epithelium of normal seminal vesicles. Moreover, an electron microscope examination revealed the presence of spindle or stellate cells in the stroma of the lamina propria beneath the seminal vesicle epithelium, and an immunoelectron microscopic examination showed that these cells were positive for ASMA. Finally, myofibroblasts are distributed in the lamina propria of human normal seminal vesicles and may play an important role in the ejection of sperm plasm.

Adenoid basal carcinoma arising in the cervical polyp: an immunohistochemical study of stromal cells.

Adenoid basal carcinomas of the uterine cervix are uncommon neoplasms and generally run a favorable clinical course. Although it is well known that these tumors do not evoke the stromal reaction, we immunohistochemically examined a stromal reaction in a case of adenoid basal carcinoma. A 40-year-old woman was found to have a cervical polyp during a medical checkup and underwent polypectomy. Histological examination revealed the finding of adenoid basal carcinoma. Immunohistochemically, a smaller number of CD34-positive and CD31-negative stromal cells, namely fibroblasts, in the stroma of tumor center than in normal cervical stroma were observed. On the other hand, alpha-smooth muscle actin-positive and h-caldesmon-negative stromal cells, namely myofibroblasts, were completely absent in the stroma of tumor center. Finally, our preliminary report suggests that the decrease of CD34-positive fibroblasts in adenoid basal carcinoma may show an early stromal reaction to tumor invasion. Gynecologists and pathologists should bear in mind that adenoid basal carcinoma may arise in a cervical polyp.

Hyaline globule-like structures in undifferentiated sarcoma cells of malignant müllerian mixed tumor of the fallopian tube.

Malignant müllerian mixed tumors (MMMTs) of the fallopian tube are very rare neoplasms, and we present such a case with unusual findings here. A 57-year-old Japanese woman, after she received a medical checkup, underwent salpingo-oophorectomy on the suspicion of ovarian cancer. At the time of operation, the main tumor was present predominantly in the fallopian tube. Microscopically, the tumor consisted of carcinoma and sarcoma components. The carcinoma showed moderately to poorly differentiated adenocarcinoma. The sarcoma consisted of predominantly undifferentiated sarcoma and focally rhabdomyosarcomatous cells with abundant eosinophilic cytoplasm. Immunohistochemically, the differentiation toward rhabdomyosarcoma was confirmed. Interestingly, the cytoplasm of undifferentiated sarcoma cells contained hyaline globule-like structures. These structures showed a positive reaction for PAS, and these structures were not digested by the diastase pretreatment. Ultrastructurally, hyaline globule-like structures corresponded to lysosomes. Finally, pathologists should keep in mind that undifferentiated sarcoma cells in MMMT of the fallopian tube may contain hyaline globule-like structures in the cytoplasm.