Masahito Yasuda

Gunma University, Maebashi, Gunma, Japan

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Publications (18)33.78 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Dermatofibrosarcoma protuberans (DFSP) is a rare skin cancer that develops in the deep dermis to subcutaneous adipose tissues. A COL1A1-PDGFB gene fusion, leading to the constitutive expression of PDGFB, is the tumorigenic mechanism in most DFSP cases. To evaluate the specificity of PDGFB expression as a diagnostic marker of DFSP and to determine whether other pathomechanisms (ie, gene fusions) exist in patients with DFSP without the COL1A1-PDGFB fusion gene. All patients with DFSP registered in the pathologic database of the University of the Ryukyus from January 1, 1997, through December 31, 2013, and Gunma University from January 1, 1996, through December 31, 2011, were included in this analysis. Samples were obtained from 30 patients presenting with DFSP tumors. We examined the clinicopathologic characteristics and the expression of PDGFB, PDGFRβ, PDGFRα, CD34, nestin, factor XIIIa, fibronectin, α-smooth muscle actin, S-100 protein, and Ki-67 in 30 DFSP cases and 48 non-DFSP mesenchymal tumor cases by immunohistochemical analysis. We then analyzed tumor tissues for the presence of the COL1A1-PDGFB fusion gene. We also tested whether other genes enriched in fibroblasts formed fusion products with PDGFB by reverse transcription-polymerase chain reaction analysis, using gene-specific primers. We aimed to analyze tumor tissues for the presence of the COL1A1-PDGFB fusion gene to investigate expression of PDGFB in DFSP tumors. PDGFB expression was detected in 28 (93%) of 30 patients with DFSP. PDGFB was not homogenously expressed in DFSP tumor cells, whereas CD34 and nestin were often expressed throughout the tumor mass. In 1 DFSP tumor, the COL1A1-PDGFB fusion gene was not detected even though PDGFB was expressed. We identified a novel COL1A2-PDGFB fusion gene in this tumor. Our findings indicate that PDGFB protein is expressed in most DFSP tumors and may be a useful diagnostic tool when used in conjunction with CD34 and nestin expression analysis. These PDGFB expression data, in addition to our discovery of a novel PDGF fusion gene, strongly support the concept that DFSP is a PDGFB-dependent tumor type.
    09/2015; DOI:10.1001/jamadermatol.2015.2389
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    ABSTRACT: Amino acid transporters play a crucial role in the development and invasiveness of cancer cells. However, it remains unclear whether or not the expression of L-type amino acid transporter 1 (LAT1) has prognostic significance in patients with cutaneous melanoma. A total of 128 patients with cutaneous melanoma were evaluated. Tumor sections were stained by immunohistochemistry for LAT1, CD98, Ki-67, and microvessel density determined by CD34 and p53. We also analyzed 30 specimens of patients with melanocytic nevi as negative controls. LAT1 and CD98 were highly expressed in 58% (75/128) and 75% (97/128), respectively. The rates of positivity for LAT1 in the melanocytic nevi were 0% (0/30). The expression of LAT1 was associated significantly with tumor thickness, T factor, CD98 expression, cell proliferation (Ki-67), and microvessel density (CD34). By Spearman's rank test, LAT1 expression was correlated with CD98, Ki-67, and CD34. By univariate analysis, tumor thickness, ulceration, disease staging, LAT1, and CD34 showed a significant relationship with overall survival and disease-free survival. Furthermore, a multivariate analysis confirmed that LAT1 was an independent prognostic factor for predicting a poor prognosis. This study had a small sample size. LAT1 can serve as a significant prognostic factor to predict a poor outcome and it may therefore play an important role in the aggressiveness of cutaneous melanoma.
    Melanoma research 07/2015; 25(5). DOI:10.1097/CMR.0000000000000181 · 2.28 Impact Factor
  • The Journal of Dermatology 05/2015; 42(9). DOI:10.1111/1346-8138.12959 · 2.25 Impact Factor
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    Acta Dermato Venereologica 01/2015; 95(6). DOI:10.2340/00015555-2054 · 3.03 Impact Factor
  • Australasian Journal of Dermatology 11/2014; 55(4). DOI:10.1111/ajd.12208 · 1.11 Impact Factor
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    ABSTRACT: Giant condyloma acuminatum (GCA) is a cauliflower-like condyloma acuminatum. Low-risk human papillomavirus (HPV) infection, such as that of HPV types 6 or 11, is associated with the disease (1). HPV type 56 is a high-risk HPV type that is sometimes detected in skin tumours (2). In particular, nail Bowen's disease presenting with longitudinal melanonychia has been reported to be frequently associated with HPV type 56 (2-4). We herein report a case of multiple giant condylomata acuminata in the groin and scrotum caused by high-risk HPV type 56 infection.
    Acta Dermato-Venereologica 11/2013; 94(4). DOI:10.2340/00015555-1755 · 3.03 Impact Factor
  • Journal of Dermatological Science 02/2013; 69(2):e35. DOI:10.1016/j.jdermsci.2012.11.405 · 3.42 Impact Factor
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    The Journal of Dermatology 01/2011; 38(1):101-3. DOI:10.1111/j.1346-8138.2010.01007.x · 2.25 Impact Factor
  • European journal of dermatology: EJD 05/2010; 20(3):401-2. DOI:10.1684/ejd.2010.0945 · 1.99 Impact Factor
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    ABSTRACT: Arteriovenous malformation (AVM) is a structural vascular abnormality with no proliferation of cellular components. We report on a 53-year-old man who presented with a 15-year history of a progressively enlarging nodule on his lower lip. A dark-reddish, easy-bleeding nodule diagnosed as AVM was resected to reduce the volume and troublesome bleeding. Histologically, the nodule revealed that the proliferating cellular area was composed of endothelial cells and pericytes in addition to the area of dilated vessels. We speculated that the cell proliferation developed secondary to AVM. We also discuss the histological differential diagnosis of spindle cell hemangioma and pseudo-Kaposi's sarcoma.
    The Journal of Dermatology 04/2010; 37(4):363-6. DOI:10.1111/j.1346-8138.2010.00788.x · 2.25 Impact Factor
  • Etsuko Okada · Masahito Yasuda · Atsushi Tamura · Osamu Ishikawa
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    ABSTRACT: Background: Dermatofibrosarcoma protuberans (DFSP) is an uncommon infiltrative tumor of the dermis and subcutaneous tissue. Recent cytogenetic studies have demonstrated a chromosomal trans-location of the collagen type I alpha 1 (COL1A1) gene on chromosome 17 to the platelet-derived growth factor B-chain (PDGFB) gene on chromosome 22. Various exons of the COL1A1 gene have been reported to be involved in the fusion with exon 2 of the PDGFB gene. Method: The COL1A1-PDGFB fusion transcript was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) using frozen tissue from 4 DFSP patients. Nucleotide sequence analyses were carried out using the PCR products to identify the breakpoints. Results: COL1A1-PDGFB fusion transcripts were detected in all tumor specimens. Sequence analyses revealed that the end of exon 25, 45, 32, or 11 in the COL1A1 gene was fused with the start of exon 2 in the PDGFB gene. Conclusion: Detection of this aberrant fusion transcript can be useful as a diagnostic method for DFSP.
    The Kitakanto Medical Journal 09/2009; 59(3):259-263. DOI:10.2974/kmj.59.259
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    ABSTRACT: Digital ulcers and gangrene are common skin manifestations of connective tissue diseases, especially systemic sclerosis, although they are relatively rare in systemic lupus erythematosus. We describe here three patients with digital gangrene and systemic lupus erythematosus. None of the patients showed high disease activity of systemic lupus erythematosus at the time the digital gangrene developed. Two patients were positive for anti-RNP antibodies; however, no symptoms of other collagen diseases were present. One patient had anti-phosphatidylserine/prothrombin complex antibodies, and the other had anti-cardiolipin beta2 glycoprotein I antibodies and lupus anticoagulant at low titre. All patients showed narrowing or occlusion of radial and/or ulnar arteries in addition to digital arteries. Although a complication of anti-phospholipid syndrome is considered to be a possible cause, there may be unidentified causes other than thrombosis, atherosclerosis, overlap syndrome and vasculitis.
    Acta Dermato-Venereologica 02/2009; 89(4):398-401. DOI:10.2340/00015555-0658 · 3.03 Impact Factor
  • M Yasuda · Y Miyachi · A Utani
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    ABSTRACT: We report two cases of dyshidrosiform pemphigoid (DP) with different presentations. One patient was a 65-year-old Japanese man, who had been diagnosed with dyshidrosis and had been treated before visiting our hospital. When we stopped all treatments, the vesicles increased and spread to the trunk and limbs. We made a diagnosis of vesicular pemphigoid (VP) that was concomitant with or transformed from DP. Using Western blotting, the sera reacted with antigens with molecular weights of 60 and 180 kDa. The 60-kDa antigen has not been found previously in the sera of patients with VP. The other patient was a 94-year-old Japanese woman, who presented with redness and swelling with bullae on the palmoplantar areas. Five days later, areas of oedematous erythema, as seen in prototypical bullous pemphigoid (BP), developed on the limbs. Study of the distribution of the BP antigen may elucidate the mechanisms involved in localized forms of BP such as DP.
    Clinical and Experimental Dermatology 02/2009; 34(5):e151-3. DOI:10.1111/j.1365-2230.2008.03083.x · 1.09 Impact Factor
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    Dermatology 08/2008; 217(2):146-8. DOI:10.1159/000135708 · 1.57 Impact Factor
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    ABSTRACT: We report a 58-year-old man with mycosis fungoides (MF) and occupational systemic sclerosis (SSc) induced by silica exposure. He was engaged in tunnel construction from the age of 18 to 33 years. He developed MF at the age of 30. Diagnosis of silicosis was made at the age of 52 and SSc at the age of 58. Physical examinations revealed sclerotic skin changes on his forearms and fingers and poikiloderma on the left popliteal fossa and inguinal region. Both antinuclear antibody and antitopoisomerase-I antibody were positive. We could find no apparent difference between his clinical features and those of idiopathic SSc except for the presence of silicosis and MF. Systemic therapy with interferon-gamma for MF did not improve the skin sclerosis. We discuss the relationship of silica exposure to both MF and SSc.
    The Journal of Dermatology 02/2008; 35(1):21-4. DOI:10.1111/j.1346-8138.2007.00405.x · 2.25 Impact Factor
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    ABSTRACT: Bowen's disease developing on mucous or mucocutaneous regions is clinically called erythroplasia of Queyrat. We report herein a 56-year-old male with Bowen's disease extending from the penis shaft to the glans penis, and urethral meatus. Physical examination revealed bright red velvety plaques on the prepuce and glans penis and an irregularly pigmented scaly lesion on the dorsum of his penis shaft. Histopathological findings of both lesions were compatible with those of Bowen's disease, supporting the concept that erythroplasia of Queyrat and Bowen's disease should be regarded as one clinicopathologic entity. A partial penectomy was finally performed, because tumor cells were pathologically observed in the mucous epithelium of the urethra. Although several therapeutic modalities exist for Bowen's disease on the external genitalia, treatment options are limited when Bowen's disease extends to the urethral meatus. We discussed the recent therapeutic modalities in genital Bowen's disease.
    The Journal of Dermatology 04/2005; 32(3):210-3. DOI:10.1111/j.1346-8138.2005.tb00747.x · 2.25 Impact Factor
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    ABSTRACT: We report two cases of Werner's syndrome (WS). First, a 42-year-old Japanese man was referred on suspicion of systemic sclerosis (SSc) because of scleroderma-like skin atrophy and foot ulcers. Second, a 51-year-old woman with malignant fibrous histiocytoma was referred on suspicion of premature aging syndrome. Because both patients had many typical manifestations compatible with WS, we made a clinical diagnosis of WS. Genetic analyses revealed a homozygous mutation, an A deletion at nucleotide 3677 of WS gene (WRN) in the first case and a homozygous mutation, a G to C substitution at one base upstream of exon 26 of WRN in the second case. Both mutations were consistent with those previously reported in Japanese WS patients.
    European journal of dermatology: EJD 11/2004; 14(6):379-82. · 1.99 Impact Factor
  • Masahito Yasuda · Masatoshi Abe · Atsushi Tamura · Osamu Ishikawa
    The Kitakanto Medical Journal 01/2002; 52(6):469-472. DOI:10.2974/kmj.52.469