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Biomedical subjects

P Bilek

Publications and source records attributed to P Bilek.

10 recordsLinked to original sources

The ABCD rule of dermatoscopy. High prospective value in the diagnosis of doubtful melanocytic skin lesions.

BACKGROUND: The difficulties in accurately assessing pigmented skin lesions are ever present in practice. The recently described ABCD rule of dermatoscopy (skin surface microscopy at x10 magnification), based on the criteria asymmetry (A), border (B), color (C), and differential structure (D), improved diagnostic accuracy when applied retrospectively to clinical slides. OBJECTIVE: A study was designed to evaluate the prospective value of the ABCD rule of dermatoscopy in melanocytic lesions. METHODS: In 172 melanocytic pigmented skin lesions, the criteria of the ABCD rule of dermatoscopy were analyzed with a semiquantitative scoring system before excision. RESULTS: According to the retrospectively determined threshold, tumors with a score higher than 5.45 (64/69 melanomas [92.8%]) were classified as malignant, whereas lesions with a lower score were considered as benign (93/103 melanocytic nevi [90.3%]). Negative predictive value for melanoma (True-Negative divided by [True-Negative+False-Negative]) was 95.8%, whereas positive predictive value (True-Positive divided by [True-Positive+False-Positive]) was 85.3%. Diagnostic accuracy for melanoma (True-Positive divided by [True-Positive+False-Positive+False-Negative]) was 80.0%, compared with 64.4% by the naked eye. Melanoma showed a mean final dermatoscopy score of 6.79 (SD, +/- 0.92), significantly differing from melanocytic nevi (mean score, 4.27 +/- 0.99; p < 0.01, U test). CONCLUSION: The ABCD rule can be easily learned and rapidly calculated, and has proven to be reliable. It should be routinely applied to all equivocal pigmented skin lesions to reach a more objective and reproducible diagnosis and to obtain this assessment preoperatively.

Dermatology↗

[The dermatoscope. A simplification of epiluminescent microscopy of pigmented skin changes].

The poor prognosis of thick malignant melanomas emphasizes the importance of their early detection. Skin microscopy using a stereomicroscope has been shown to increase the accuracy of clinical diagnosis significantly in pigmented skin lesions. Owing to the development of the Heine Delta 10 dermatoscope, skin microscopy has become less difficult and more rapid. Therefore, this technique can now be applied routinely in daily office practice.

Basal Cell Carcinoma↗

[DNA impulse cytophotometry measurements in head and neck tumors. Initial results of a correlation with clinical stage, therapeutic response and pattern of recurrence].

The DNA index and proliferation rate (percentage of S-phase cells) of 52 head and neck tumours were analysed by flow cytometry. Thirty-one (60%) of these tumours were aneuploid, 21 (40%) diploid. The distribution of aneuploid tumours was nearly equal in all T-stages. In contrast, the number of aneuploid tumours increased with higher N-stages. Locoregional recurrences developed more often (69%) in aneuploid tumours than in diploid tumours (54%). Furthermore, recurrence presented earlier (median 5 months) than in the latter (median 11 months). Regional recurrences were mainly observed in aneuploid tumours, local recurrences in diploid tumours.

DNA, Neoplasm↗

[Flow cytophotometric measurements before and during radiotherapy of head and neck tumors].

The DNA index and proliferation activities were determined by flow cytophotometry in 59 tumors of the head and neck area. 35 tumors (59%) were aneuploid, 24 (41%) were diploid. Aneuploid tumors showed a tendency to increased formation of lymph node metastases, an increased risk of relapse as well as a shorter relapse-free interval. No correlation was found between the primary tumor stage and the incidence of aneuploid tumors. Whereas aneuploid tumors developed frequently regional recurrences, only local recurrences were observed in diploid tumors. A number of biopsies was additionally performed during radiotherapy in twelve tumors. After 10 or 20 Gy, aneuploid tumors showed a considerably increased number of S and S2 + M phase cells. In diploid tumors, substantial modifications of the cell cycle phases were not found, because it is not possible in these cases to distinguish between normal cells and tumor cells.

Aneuploidy↗