Continuous wave electron paramagnetic resonance (CW EPR) and X-band (9 GHz) EPR imaging (EPRI) were used to nondestructively investigate the possible differentiation between malignant melanoma (MM) and nevus pigmentosus (NP) melanin radicals in paraffin-embedded specimens. The EPR spectra of both samples were analyzed using linewidth, spectral pattern, and X-band EPRI. The CW-EPR spectra of the MM showed an additional signal overlap. Eumelaninand pheomelanin-related radicals were observed in the MM specimens. The EPR results revealed that the peak-to-peak linewidths (ΔHpp) of paraffin-embedded MM and NP samples were 0.65 ± 0.01 and 0.69 ± 0.01 mT, respectively. The g-value was 2.005 for both samples. Moreover, the two-dimensional (2D) EPRI of the MM showed different signal intensities at the different tumor stages, unlike the NP, which displayed fewer variations in signal intensity. Thus, the present results suggest that EPR and 2D EPRI can be useful for characterization of the two melanin radicals in the MM and for determination of their size and concentration.

No abstract

No abstract

No abstract

No abstract

Nail cosmetics and adornments are widely used in today's society. However, their histologic features are not well characterized. Routine histologic examination and polarization of nail plate specimens in our academic dermatopathology practice at the Hospital of the University of Pennsylvania revealed 3 distinct histologic patterns of nail cosmetics: a hyperpigmented pattern with diffuse fine granular material, a layered pattern with a single linear band of polarizable material, and a hyperpigmented pattern with larger granules containing flecks of polarizable material. In our experience, submitting clinicians rarely indicate the patient's use of nail polish or other enhancements. Recognition of the histologic features of nail cosmetics is important to prevent confusion with dermatoses affecting the nail unit, and it will help dermatopathologists render more accurate diagnoses.

No abstract

Basal cell carcinoma (BCC) in paraffin-embedded specimens was investigated by nondestructively electron paramagnetic resonance (EPR) and X-band (9.45 GHz) EPR imaging (EPRI). A histopathological examination of specimens showed the melanin contents and revealed that they were predominantly of the nodular types. A single-line EPR pattern was observed in the BCC specimens, and the spectra of the samples were analyzed using linewidth and spectral pattern parameters. The eumelanin-related radical was observed in paraffin-embedded BCC specimens. The stability of the radical was supported by sepia pigment experiments. The g-value and peak-to-peak linewidths (ΔHpp) were 2.0046 and 0.61 ± 0.02 mT (mean ± SEM), respectively. Strong EPRI signals correspond to areas of strong pigmentation in the samples. Thus, histopathological examination, EPR, and EPRI of BCC specimens showed that the radical distribution reflects on the spatial distribution of pigments in the samples.