Biomedical subjects

Yasushi Ishihara

Publications and source records attributed to Yasushi Ishihara.

3 recordsLinked to original sources

PubMed2006

Early acral melanoma in situ: correlation between the parallel ridge pattern on dermoscopy and microscopic features.

In non-white populations, acral skin is the most prevalent site of malignant melanoma. Early melanomas of this anatomic site are often misdiagnosed as melanocytic nevi, which are not uncommon on acral skin. In fact, clinical and/or histopathological features of melanocytic nevi occasionally mimic those of early acral melanoma and vice versa, and thus differentiation of early acral melanoma from melanocytic nevus is sometimes very difficult for clinicians as well as for histopathologists. Our dermoscopic investigation has revealed that the parallel ridge pattern, a band-like pigmentation on the ridges of the skin markings, is highly specific to malignant melanoma in situ on acral volar skin. In the present study, we reviewed 22 acral melanocytic lesions that showed the parallel ridge pattern on dermoscopy but had very subtle clinical and/or histopathological presentations. We diagnosed 20 of them as early melanoma in situ by careful histopathological examination, which revealed histopathological features very similar to those seen in macular portions of overt acral melanoma, but fundamentally different from features found in melanocytic nevi on acral skin. In correspondence with their dermoscopic pattern, in these early lesions of acral melanomas, proliferation of solitary arranged melanocytes was mainly detected in the crista profunda intermedia, the epidermal rete ridge underlying the ridge of the skin marking. The two remaining lesions were diagnosed as possible cases of acquired melanocytic nevus because of the formation of well-demarcated nests of melanocytes in the epidermal rete ridges. We propose that a finding of preferential proliferation of solitary arranged melanocytes in the crista profunda intermedia is an important clue for the histopathological diagnosis of early phases of acral melanoma.

Adult↗

PubMed2005

[Autoantibodies].

The autoantibody test gives significant information for diagnosis of autoimmune diseases. Since the finding of the LE-cell in 1948, dozens of autoantibodies have been found. Anti nuclear antibody (ANA) is the essential test for the screening of autoantibodies. Indirect immunofluorescence (IIF) is the conventional method for the detection of ANA. IIF can detect a wide spectrum of ANA and gives abundant information obtained from a staining pattern. However under the recent circumstances of using advanced fluorescent microscopes and reagents we often have difficulty interpreting positive results seen in normal individuals and in detailed staining patterns. ELISA (enzyme-linked immunosorbent assay), detecting disease specific autoantibodies alone, is one solution. Some antibodies such as anti-DNA or anti-ENA (extractable nuclear antigen) have a strong relation to specific diseases. These autoantibodies have been detected by IIF, RIA (radioimmunoassay) or DID (double immune diffusion). With the progress of molecular biology many autoantigens have been characterized. Now ELISA is a typical way to detect autoantibodies because purified or recombinant antigens are easily available. Though RF (rheumatoid factor) is the historical autoantibody detected in RA patients, the specificity to RA is low. The new anti-CCP is promising from its high specificity and sensitivity. Now we can choose various kind of autoantibody tests, not only conventional ones but also newly developed ones. For diagnosis and treatment of autoimmune diseases, understanding of both clinical significance and methodology is important.

Animals↗

PubMed2004

Significance of dermoscopic patterns in detecting malignant melanoma on acral volar skin: results of a multicenter study in Japan.

OBJECTIVE: To determine diagnostic variables such as sensitivity and specificity of the major dermoscopic patterns observed in melanocytic lesions on acral volar skin, with particular attention to the significance of the parallel ridge pattern and irregular diffuse pigmentation in detecting acral melanoma. DESIGN: Multicenter, retrospective study. SETTING: University hospitals in Japan. PATIENTS: Patients with melanocytic lesions on acral volar skin. A total of 712 melanocytic lesions (103 malignant melanomas, including 36 in situ lesions, and 609 melanocytic nevi) were consecutively collected from the files of 3 hospitals. Diagnoses of all the lesions had been determined histopathologically. INTERVENTIONS: Dermoscopic examination. MAIN OUTCOME MEASURES: The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the major dermoscopic patterns seen in benign and malignant melanocytic lesions on acral volar skin. RESULTS: The parallel ridge pattern and irregular diffuse pigmentation showed extremely high specificity (99.0% and 96.6%, respectively) and very high negative predictive value (97.7% and 97.5%, respectively) in malignant melanoma. For melanoma in situ, the positive predictive value and diagnostic accuracy of the parallel ridge pattern were significantly higher than those of irregular diffuse pigmentation (P = .009 and P = .006, respectively). In melanocytic nevi, the specificity and positive predictive value of the parallel furrow pattern and/or the latticelike pattern were found to be very high (93.2% and 98.3%, respectively). CONCLUSIONS: Dermoscopy is immensely helpful in differentiating malignant melanomas from melanocytic nevi on acral volar skin. Moreover, the parallel ridge pattern aids in detecting acral melanomas in early, curable stages.

Adult↗