Hirotake Nishimura

Cellular Localization of Sphingosine-1-phosphate Receptor 1 Expression in the Human Central Nervous System

Sphingosine-1-phosphate (S1P), a potent lipid mediator, transduces intracellular signals through the activation of S1P receptors (S1PRs). Although S1PRs have been shown to play an important role in the central nervous system (CNS), accurate localization and the function of S1PR1 in the human CNS are still unclear. In this study, we investigated the localization of S1PR1 in the human CNS of postmortem samples, using a rabbit polyclonal antibody, the specificity of which had been well defined. Immunohistochemical investigation of paraffin-embedded sections revealed diffuse granular staining of the gray matter. The signals of the gray matter were much stronger than those of the white matter. The immunohistochemical expression levels correlated well with the results of quantitative real-time RT-PCR-based analysis and Western blotting. Studies using double immunostaining and immunoelectron microscopy revealed that the antigen was strongly expressed in the membrane of the astrocytic foot processes of glia limitans and astrocytes with radial cytoplasm, but not distributed in neurons. In neurological disorders, hypertrophic astrocytes with strong expression of glial fibrillary acidic protein exhibited significantly decreased expression of S1PR1 in contrast to its strong expression in astrocytes forming fibrillary gliosis. These results indicate that S1PR1 is localized in astrocytes, and its expression level may change during the processes that occur after brain damage.

Expression of sphingosine-1-phosphate receptor 1 in mantle cell lymphoma

The distribution and pathological significance of sphingosine-1-phosphate receptor 1 expression are still unclear. In this study, we evaluated sphingosine-1-phosphate receptor 1s suitability as a diagnostic marker for malignant lymphoma by immunostaining formalin-fixed paraffin-embedded sections using a well-defined commercial anti-sphingosine-1-phosphate receptor 1 antibody. Sphingosine-1-phosphate receptor 1 was strongly expressed on the surface of small lymphocytes forming primary lymphoid follicles and in the mantle zone of secondary lymphoid follicles. Microarray-based immunohistochemistry with tissue samples from 85 lymphoid malignancy cases demonstrated that sphingosine-1-phosphate receptor 1 was expressed on the surface of mantle cell lymphoma cells. Strong expression was observed in all classical mantle cell lymphoma cases involving the lymph node (19 out of 19), gastrointestinal tract (10 out of 10), bone marrow (9 out of 9), and orbita (1 out of 1). Good results were obtained even in sections where cyclin D1 signals were lost because of over-fixation and/or decalcification. One aggressive variant of mantle cell lymphoma displayed a weaker membranous staining than classical mantle cell lymphoma in the lymph node and bone marrow. In a cyclin D1-negative mantle cell lymphoma of the orbita, no conclusive result was obtained. No cases of follicular lymphoma, marginal zone lymphoma, B lymphoblastic leukemia/lymphoma, or Burkitts lymphoma showed any significant expression, whereas 2 out of 6 chronic lymphocytic leukemia/small lymphocytic lymphomas in bone marrow, 1 out of 3 lymphoplasmacytic lymphomas in the lymph node, and 2 out of 37 diffuse large B-cell lymphomas exhibited staining. A quantitative reverse transcription polymerase chain reaction-based analysis of mantle cell lymphoma lines revealed the sphingosine-1-phosphate receptor 1 mRNA expression level to be well correlated with the results of immunocytochemistry, flow cytometry, and western blotting. Thus, sphingosine-1-phosphate receptor 1 immunohistochemistry may be useful in the histological diagnosis of mantle cell lymphoma with formalin-fixed and paraffin-embedded sections. The antigen may be particularly valuable in cases where cyclin D1 immunostaining is not successful.

Tissue gadolinium deposition in renally impaired rats exposed to different gadolinium-based MRI contrast agents: evaluation with inductively coupled plasma mass spectrometry (ICP-MS).

OBJECTIVES To quantify tissue gadolinium (Gd) deposition in renally impaired rats exposed to Gd-EOB-DTPA and other Gd-based MRI contrast agents by means of inductively coupled plasma mass spectrometry (ICP-MS), and to compare the differences in distribution among major organs as possible triggers for nephrogenic systemic fibrosis (NSF). METHODS A total of 15 renally impaired rats were injected with Gd-EOB-DTPA, Gd-DTPA-BMA and Gd-HP-DO3A. Gd contents of skin, liver, kidney, lung, heart, spleen, diaphragm and femoral muscle were measured by inductively coupled plasma mass spectrometry (ICP-MS). Histological assessment was also conducted. RESULTS Tissue Gd deposition in all organs was significantly higher (P=0.005~0.009) in the Gd-DTPA-BMA group than in the Gd-HP-DO3A and Gd-EOB-DTPA groups. In the Gd-DTPA-BMA group, Gd was predominantly deposited in kidney (1306±605.7μg/g), followed by skin, liver, lung, spleen, femoral muscle, diaphragm and heart. Comparing Gd-HP-DO3A and Gd-EOB-DTPA groups, Gd depositions in the kidney, liver and lung were significantly lower (P=0.009~0.011) in the Gd-EOB-DTPA group than in the Gd-HP-DO3A group although no significant differences were seen for any other organs. CONCLUSIONS Gd-EOB-DTPA is a stable and safe Gd-based contrast agent (GBCA) showing lower Gd deposition in major organs in renally impaired rats, compared with other GBCAs. This fact suggests that the risk of NSF onset would be low in the use of Gd-EOB-DTPA.

Enhanced carotid plaque on contrast-enhanced ultrasound is associated with plaque instability and rupture.

Background: Ischemic stroke is one of causes of atherosclerotic diseases, and is closely associated with vulnerable plaque at the origin of the internal carotid artery. Several studies have shown that neovascularization in atheromatous plaque serves as a reliable maker of plaque vulnerability.Contrast-enhanced ultrasound (CEUS) can demonstrate the presence of carotid intraplaque neovascularization. The aim of the present study was to investigate the histopathologic findings of enhanced carotid plaque on CEUS. Methods: We studied consecutive 18 patients (16 men, mean age 69.4 ± 6.7 years) who underwent carotid endarterectomy. Enhanced plaque was classified into two subgroups: a spotty pattern as moving bright spots within plaque (Figure 1A, Panel A); and a linear pattern, where enhanced lesions appeared as a line from intima into plaque (Figure 1B, Panel A). Sonazoid (Daiich-Sankyo, Tokyo, Japan), perflurobutane microbubbles, was used as the contrast agent. A bolus intravenous injection of Sonazoid (0.015 mL/kg body weight (0.12 μ L perflurobutane microbubble /kg body weight)) was performed via the peripheral venous line followed by a flush with 10 mL of normal saline. We investigated the association between enhanced plaque on CEUS and histopathologic findings. Results: CEUS revealed enhanced plaque in 11 (61.1%) of 18 patients. Only a spotty pattern (spotty subgroup) was observed in 5 patients, whereas both a spotty and linear pattern (linear subgroup) was observed in 6. The amount of neovascularization was larger in enhanced than in non-enhanced plaque (6.79 ± 5.17/2.5 mm 2 vs. 1.12 ± 0.90/2.5 mm 2 , P=0.001). Furthermore, the enhanced group had more macrophage aggregation (7.76 ± 3.70% vs. 4.23 ± 1.63%, P=0.030) and intraplaque hemorrhage (18.84 ± 14.88% vs. 5.52 ± 9.68%, P=0.013) compared with the non-enhanced group. Thin fibrous cap ( Conclusions: Enhanced plaque on CEUS indicates vulnerable plaque. A linear pattern of enhanced plaque indicates plaque rupture. Enhanced plaque on CEUS should become a new surrogate marker of vulnerable carotid plaque.

Small cell variant of anaplastic large cell lymphoma diagnosed by a novel chromosomal abnormality t(2;5;3)(p23;q35;p21) of bone marrow cells

Because of the rarity and the morphological variations, small cell variant of anaplastic large cell lymphoma (ALCL) represents a diagnostic challenge. Herein is reported a case of leukemic type of small cell variant of ALCL, in which the diagnosis was established by a cytogenetic analysis. The patient was a 23‐year‐old woman who presented with fever and leukocytosis with circulatory atypical lymphoid cells. The initial differential diagnosis on bone marrow trephine biopsy sections included viral infection and peripheral T‐cell lymphoma unspecified. But a cytogenetic study on bone marrow cells indicated a novel complex translocation, t(2;5;3)(p23;q35;p21), which led to confirmation of anaplastic lymphoma kinase (ALK)‐positive pleomorphic small to medium‐sized cells scattered in bone marrow cells, on immunohistochemistry. ALK was distributed in both nuclear and cytoplasmic regions of neoplastic cells. The patient achieved complete remission after four courses of combination chemotherapy, and received autologous peripheral stem cell transplantation (auto‐PBSCT) after two additional courses of combination chemotherapy, but relapsed 2 months after auto‐PBSCT in the bilateral lung. Allogeneic stem cell transplantation led to a second remission. This case demonstrates the diagnostic importance of cytogenetic study for malignant lymphoma involving bone marrow.

Chronic encapsulated intracerebral hematoma: Three case reports and a literature review

Background: Chronic encapsulated intracerebral hematoma (CEIH) is one type of intracerebral hematoma that sometimes grows progressively while forming a capsule and presenting with neurological deficits. Although many cases of CEIH have been reported, correct preoperative diagnosis is very difficult. Only around 20% of cases are diagnosed preoperatively. Case Description: We encountered three cases of CEIH in which causes were unidentified and difficult to diagnose. All three cases were treated surgically. In the first case, a 59-year-old male was diagnosed preoperatively with metastatic brain tumor. In the second case, a 62-year-old female was diagnosed preoperatively with glioblastoma. The third case involved a 58-year-old female diagnosed preoperatively with CEIH. Conclusion: We should keep in mind that CEIH is a differential diagnosis for intracerebral space-occupying lesions. This report describes these three cases and discusses imaging findings and characteristics of CEIH.

Magnetic resonance imaging diagnosis of panniculitis in dermatomyositis

A 64-year-old woman noticed gradual weakness in her legs and difficulty in walking, followed by weakness in her arms and neck 4 months prior to admission. At the time of admission the patient was unable to get up from bed and was unable to lift her arms above her head. Abnormal neurological findings included MRC (Medical Research Council scale) strength of 2 in neck flexors, 3 in deltoids and biceps, 4 in hand grip, 3 in iliopsoas, and 4 in hamstrings and anterior tibialis muscles. She also had moderate atrophy in her upper arms and thighs. Erythematous rashes were noted over her arms, trunk, legs, and face. Multiple cutaneous ulcers of her elbows, wrists, and toes were first noticed 2 months after the onset of weakness. Laboratory findings included normal creatine kinase, mildly elevated aldolase, high sedimentation rate, and negative anti-Jo-1 antibody. An extensive cancer work-up was negative. Needle electromyography showed significant findings indicative of active myopathy. Magnetic resonance imaging (MRI) of the bilateral thighs showed marked enlargement of subcutaneous fat tissue (Fig. 1A,B). The subcutaneous fat showed a diffuse reticular pattern with low signal intensity on T1-weighted images (Fig. 1A). Short tau inversion recovery (STIR) images showed high signal intensity in regions with low signal intensity on T1-weighted images (Fig. 1B). These MRI findings suggested extreme subcutaneous edema and inflammation caused by panniculitis. Muscle biopsy from the left biceps brachii revealed perivascular lymphocytic inflammation and perifascicular muscle fiber atrophy consistent with a diagnosis of dermatomyositis (not shown). A subcutaneous fat biopsy specimen from the site of the muscle biopsy showed extensive lymphohistiocytic panniculitis (Fig. 1D). Once the diagnosis had been made, treatment with prednisolone at 40 mg/day was started. Immediately after the start of treatment, gradual improvement in the strength of her neck and proximal muscles was seen, and she was able to walk independently at the time of discharge. Follow-up T1-weighted images done 3 months after treatment showed normalized intensity and thickness in subcutaneous fat tissue (Fig. 1C). Cutaneous findings such as Gottron’s sign and heliotrope erythema in dermatomyositis are well known, but, clinically, subcutaneous involvement appears to be uncommon. Since the first report of panniculitis associated with dermatomyositis by Weber and Gray in 1924, only 20 cases have been reported in the literature. However, histological changes of panniculitis are more frequently observed in biopsy specimens from subcutaneous fat tissue. The incidence of these histological changes has been reported to be 3.4% by Solans et al. and 9.1% by Janis and Winkelmann. Fusade et al. considered that the discrepancy between frequencies of clinical manifestations and histological changes indicated a variable degree of severity of panniculitis. Since panniculitis is only found incidentally by biopsy in most cases, it may be an underreported finding in dermatomyositis. On the basis of clinical data in 21 panniculitis cases with dermatomyositis (our case and literature review), the sites of panniculitis were the thigh in 12 cases (57.1%), arm in 12 cases (57.1%), buttocks in 11 cases (52.4%), and abdomen in four cases (19.0%). Dates of diagnosis of panniculitis relative to the onset of dermatomyositis were antecedent in four cases (19.0%), concurrent in five cases (23.8%), and subsequent in 12 cases (57.1%). The most notable feature in our case was that MRI suggested the presence of panniculitis with dermatomyositis before biopsy from subcutaneous fat tissue. In addition, MRI was useful for assessing the effectiveness of treatment with a steroid for panniculitis. Tests should include MRI to search for signs of panniculitis, because nearly all dermatomyositis cases with panniculitis respond well to steroids, and good disease control is achieved with immunosuppressive therapy. VC 2009 Wiley Periodicals, Inc.

Sphingosine-1-phosphate receptor 1 as a prognostic biomarker and therapeutic target for patients with primary testicular diffuse large B-cell lymphoma

Sphingosine‐1‐phosphate (S1P) is a potent lipid mediator that is produced during the metabolism of sphingolipid by sphingosine kinase. S1P has been implicated in the migration and trafficking of lymphocytes and several lymphoid malignancies through S1P receptors. Moreover, the overexpression of sphingosine‐1‐phosphate receptor 1 (S1PR1) has been correlated with the constitutive activation of signal transducer and activator of transcription (STAT)3 and poor prognosis of diffuse large B‐cell lymphoma (DLBCL). Thus, in this study, we examined the expression of S1PR1 in 198 DLBCL samples collected from nodal and various extranodal sites and sub‐classified formalin‐fixed paraffin‐embedded tissue samples into germinal centre B‐cell‐like (GCB) and non‐GCB subgroups using immunohistochemistry. These analyses showed S1PR1 overexpression in 15·7% of all cases with DLBCL and in 54·2% of 24 cases with primary testicular (PT)‐DLBCL; S1PR1 expression correlated with S1PR1mRNA expression and STAT3 phosphorylation in fresh samples. Analyses of data from a single institution suggested that S1PR1 overexpression was an independent negative prognostic marker in 68 patients with DLBCL of clinical stages I and II. The present high prevalence of S1PR1 overexpression warrants the consideration of PT‐DLBCL as a distinct disease subtype and suggests the potential of the S1P/S1PR1 axis as a therapeutic target.

Sphingosine-1-phosphate receptor 1 is a useful adjunct for distinguishing vascular neoplasms from morphological mimics

Sphingosine-1-phosphate receptor 1 (S1P1) has been shown to play an important role in the migration, proliferation, and survival of endothelial cells. S1P1 of vascular and lymphatic endothelial cells can be detected by immunostaining of paraffin-embedded sections using a rabbit anti-S1P1 antibody. In this study, to distinguish vascular tumors from histologic mimics using immunohistochemical means, we evaluated the expression of S1P1 in a range of vascular tumors. S1P1 expression was observed in eight of eight hemangiomas, four of four lymphangiomas, four of four epithelioid hemangioendotheliomas, three of three Kaposi’s sarcomas, and 15 of 15 angiosarcomas with vasoformative, spindle, epithelioid, and undifferentiated features. Conventional analysis and use of a tissue microarray of soft tissue tumors revealed three of 21 liposarcomas to have weak cytoplasmic staining and one of five squamous cell carcinomas to have membranous staining in a very limited area among 115 nonvascular tumors including histological mimics of angiosarcoma such as undifferentiated carcinoma, melanoma, and epithelioid sarcoma. The sensitivity with regards to the angiosarcoma cases was equal to, or even exceeded in undifferentiated angiosarcoma, that of CD31. Based on this study, S1P1 may be a useful adjunct to CD31 in cases where a vascular neoplasm requires a differential diagnosis.

Primary intestinal NK-cell lymphoma with a CD8+ CD56+ immunophenotype: A case report

To the Editor: The World Health Organization (WHO) classification recognizes extranodal natural killer (NK)/T-cell lymphoma, nasal type, which is defined by the expression of CD3e and cytotoxic molecules, and by Epstein-Barr virus (EBV) infection, and occurs most commonly in the upper aerodigestive tract. Although nasal-type NK/T-cell lymphoma is prevalent in Asians, primary NK-cell lymphoma of intestinal origin is quite rare. An international peripheral T-cell lymphoma project reported that 14% of 116 extranodal NK/T-cell lymphomas of nasal type express CD8, although the clinical significance of this CD8 expression is unknown. Expression of both CD8 and CD56 in intestinal lymphoma suggests a type 2 enteropathy-associated intestinal T-cell lymphoma (EATCL), because CD8 expression is exceptionally rare in intestinal NK/T-cell lymphoma of nasal type and has been shown in only one case reported by Chuang et al. In this report, we describe a case of primary intestinal CD8-positive NK-cell lymphoma with EBER-positive CD8-positive small lymphocytes in the mucosa uninvolved by lymphoma. The patient was a 63-year-old man complaining of tarry stool and mild fever. He had suffered from fever of 37–39 degrees for 3 months. He complained of epigastralgia and presented with weight loss of 5 kg. Gastroendoscopic examination revealed no abnormality. He had not been immuno-compromised and had no previous symptoms or signs of chronic diarrhea, malabsorption, or inflammatory bowel disease. There was no superficial lymph node swelling. Laboratory data were as follows: WBC 4730/mL (Neutro 63.5%, Lymph 30.0%, Mono 5.5%, Eos0.6%, Baso 0.4%), RBC 343 ¥ 10/mL, Hb 11.1 g/dL, Hct34.1%, Plt30.6/mL TP 7.2 g/dL, Alb3.9 g/dL, AST 22 U/L, ALT 18 U/L, LDH 135 IU/L, ALP 289 U/L, g-GTP 14 U/L, ChE 332 U/L, Amy84 U/L, creatinine 0.80 mg/dL, UA 5.7 mg/dL, BUN 18 mg/dL, T-Bil0.4 mg/dL, CRP 0.25 mg/dL, Na 137 mEq/L, K 4.2 mEq/L and Cl 104 mEq/L and serum antibody against HIV was negative. Because of bleeding, he underwent intestinal endoscopy, which revealed an ulcerative lesion of the jejunum. A biopsy specimen showed that pleomorphic lymphoid cells had infiltrated the intestinal mucosa. Immunohistochemically, these cells reacted with CD3e, CD8, CD56, granzyme B and TIA-1, but not with CD20, CD4, CD5, CD79a and CD68. EBER-1 in situ hybridization showed that positive signals were distributed in the nuclei of large lymphoma cells. Thus, extranodal NK/T cell lymphoma of nasal type was suspected. No involvement was found in other sites including the nasopharygeal region, skin and bone marrow. After the histological diagnosis was given, The patient underwent segmental resections of the jejunum with ulcerated lesion. The tumor formed an ulcerated lesion that was demarcated from adjacent mucosa with a normal appearance. The tumor cells were mediumto large-sized cells with round to oval nuclei with conspicuous nucleoli, scanty cytoplasm and were characterized by a slightly pleomorphic appearance (Fig. 1a). The tumor cells did not show epitheliotropism, infiltrated into the muscular layer and showed slight affinity for vessels, infrequently showing angiocentric patterns. Inflammatory reactions were seen on the serosal side of the tumor. In the touch smear cytology, the tumor cells had irregularly shaped nuclei and relatively plump cytoplasm containing a considerable number of cytoplasmic azurophilic granules. These features are typical of large granular lymphocytes. Flow cytometric analysis revealed that the tumor cells were positive for CD2, CD7, CD8 and CD56 and negative for CD3, CD4, CD5, CD13, CD14 and CD33. Immunohistochemistry on paraffin sections showed that the tumor cells were positive for CD3e, CD8 (Fig. 1b), CD30, CD56 (Fig. 1c), granzyme B, TIA-1 and LMP-1, while they were negative for CD4, CD20 and bF1. EBER-1 in situ hybridization showed that positive signals were distributed in the nucleoli of the tumor cells (Fig. 1d). Combination staining with EBER in situ hybridization and immunohistochemistry revealed that EBER-positive tumor cells were positive for CD3e and CD8 (Fig. 1e). Intestinal NK/T-cell lymphoma of nasal type should be differentiated from, not only type II EATCL, but also the recently described benign gastrointestinal NK-cell enteropathy. Type II EATCLs may exhibit similar clinicopathological features to nasal-type NK/T-cell lymphoma, that is, a progressive deeply ulcerated lesion and the expression of CD3e, CD56 and CD8, but the lymphoma shows abTCR or gdTCR phenotype and is consistently negative for EBER. Atypical lymphocytes of NK-cell enteropathy show a phenotypically and genetically similar configuration to nasal type NK/T-cell lymphoma, but the disease is a superficial ulcerated lesion and atypical lymphocytes do not harbor EBV. The technical quality and accuracy of interpretation of TCR analysis seem to be crucial for the differential diagnosis of intestinal T-cell and NK-cell lymphomas. Although DNA isolated from formalin-fixed and paraffin-embedded (FFPE) samples may often be of poor quality and unsuitable for PCR-based analysis, most reported cases of intestinal NK-cell lymphoma were defined by PCR-based TCR gene rearrangement studies of FFPE tissues. Even using the Pathology International 2013; 63: 138–140 doi:10.1111/pin.12034 bs_bs_banner