الفهرس 
DermoscopyOnly 14 pages are availabe for public view
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Abstract
Dermoscopy is an aiding diagnostic tool that allows the in vivo evaluation of colors and microstructures of the epidermis, the dermo-epidermal junction, and the papillary dermis which are not visible to the naked eye. Its idea depends on trans-illumination of a lesion and studying it with a high magnification. Old dermoscopes required application of certain oil over the lesion to be examined while new dermoscopes are provided with polarized light, rendering the fluid placed on the lesion unnecessary for inspecting pigmented skin structures. Dermoscopes are classified into dermoscopes without image capturing facility, dermoscopes with image capturing facility and dermoscopes with image capture facility and analytical capability.
Dermoscopes are used mainly for the study of melanocytic nevi and melanoma and to differentiate them from other pigmented lesions (PSLs). However, they can be used to diagnose other conditions too, e.g. psoriasis, lichen planus, dermatofibroma, Darier’s disease, cicatricial alopecia, seborrheic keratosis, urticarial vasculitis, raynaud’s phenomenon, striae distensae, mucinous carcinoma, porokeratosis, clear cell acanthoma, angioma serpiginosum, solitary angiokeratoma, fibroepithelioma of Pinkus, Bowen’s disease, actinic keratosis, sebaceous hyperplasia, scabies, pediculosis and vitiligo.
In assessing dermoscopic images, both global and local features can be recognized. Global features include reticular pattern, globular pattern, cobblestone pattern, homogenous pattern, starburst pattern, parallel pattern, multicomponent pattern, lacunar pattern, unspecific pattern. Local features include, pigment network, dots and globules, streaks, blue-whitish veil, pigmentation, hypopigmentation, regression structures, vascular structures, milia like cysts, comedo-like openings, exophytic papillary structures, red lacunas, leaf-like areas, central white patch.
There are different dermoscopic diagnostic procedures including, the two-step dermoscopy algorithm, ABCD rule of dermoscopy, the 7-point checklist, rule of three points, Menzies scoring method, pattern analysis, CASH algorithm and stratification of risk level.
In our study we used dermoscopy in the examination of PSLs among Egyptians, white skinned Europeans and Americans. Most of the Egyptian patients were of skin phototype IV while most of the Europeans and Americans were of skin phototype II. The most commonly detected PSLs among Egyptians, Europeans and Americans were acquired melanocytic nevi followed by seborrheic keratosis, solar lentigines and cherry angiomas. The detected cases of seborrheic keratosis were more frequent among Egyptians while Reed’s nevi were more frequent among Europeans and Americans, with statistically significant difference between both groups. There was no statistically significant difference between both groups as regards other types of PSLs.
The reticular pattern was the most common pattern in acquired melanocytic nevi in both groups. The globular and combined patterns were common as well and were more prevalent in the white population than in Egyptians.
Arborizing vessels were the most common dermoscopic finding in the detected cases of BCC.
Among nine biopsies taken from nine suspicious lesions, four lesions were proved to be malignant while the remaining five lesions were proved to be benign. The five malignant cases were three cases among Egyptians (a case of nodulo-ulcerative BCC, a case of superficial BCC and a case of cutaneous metastasis from the breast) and 1 case among Europeans and Americans which was a case of nodulo-ulcerative BCC.
In our study we have correlated between dermoscopy and histopathology of suspicious lesions only so we were able to detect only the sensitivity while the specificity could not be established. The sensitivity of dermoscopy in our study was 100% as there were no false negative cases.