Histologic distinction between subungual lentigo and melanoma.
ABSTRACT The distinction between a benign subungual pigmented macule (lentigo) and an early lesion of melanoma in situ can be difficult. To identify histologic parameters of potential diagnostic value, we retrospectively reviewed biopsies and excisions of 35 pigmented nail lesions. We studied 20 melanomas (10 invasive and 10 noninvasive) and 15 benign subungual melanotic lentigines. Ten specimens of normal nail apparatus obtained for reasons other than melanonychia were also examined as controls. The parameters, which were analyzed, included the density of melanocytes, the presence of multinucleated cells, pagetoid spread, cytologic atypia, inflammation, and the distribution of melanin pigment. The density of melanocytes was measured as the number of cells per 1 mm stretch of subungual dermo-epithelial junction [=melanocyte count (MC)]. The MC for invasive melanomas was as follows: mean=102, median=92.5, and range 52 to 212. For noninvasive (only in situ) melanoma, the mean MC was 58.9, median 51, and range 39 to 136. For benign subungual melanotic macules, the mean MC was 15.3, median 14, and range 5 to 31. In normal controls, the mean MC was 7.7, median 7.5, and range 4 to 9. Qualitative features associated with in situ melanoma and useful for its distinction from benign subungual melanotic macules included the presence of confluent stretches of solitary units of melanocytes, multinucleated melanocytes, lichenoid inflammatory reaction, and florid pagetoid spread of melanocytes.
Article: Longitudinal melanonychias[Show abstract] [Hide abstract]
ABSTRACT: Melanonychia is black or brown pigmentation that appears in the fingernails and toenails. The pigment can come from exogenous sources, such as bacteria or fungal infection, tar, or blood. Endogenous causes include aberrant melanin production in the nail bed, resulting in a longitudinal presentation. Melanonychia can indicate the presence of cancerous growths, as well as infection. Diagnostic measures, including dermatoscopy, biopsy, and histopathology, can determine the cause and direct the course of treatment. Malignant lesions should be excised, and underlying infections should be addressed with antibiotics or antifungals. Benign lesions and hyperpigmentation may benefit from a wait-and-see approach.Clinics in dermatology 09/2013; 31(5):594-601. DOI:10.1016/j.clindermatol.2013.06.007 · 1.93 Impact Factor
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ABSTRACT: A large signal measurement system for characterisation of high power packaged devices has been developed. The system is based upon the Microwave Transition Analyser (HP 78002) integrated with a novel test jig which has been developed `in-house¿. The measurement system is fully vector corrected to the device planes and allows measurement of the magnitude and phase of the output harmonics under different drive levels, dc bias conditions, fundamental load impedance and frequency. Measured results are shown for a 4W Bipolar device.
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ABSTRACT: The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope or chloroplasts and peroxisomes. Mitochondria divided by different mechanisms and became enclosed in Golgi and ER derived authopagic vacuoles or in the central vacuole. Several fold increase of the diameter of cristae became typical. In all cases mitochondria were attached to nuclear envelope. It can be considered as structural mechanism of promoting of PCD.Cell Biology International 01/2006; 29(12):1050-6. DOI:10.1016/j.cellbi.2005.10.004 · 1.64 Impact Factor