Epiluminescent light microscopy of melanocytic lesions after dermoepidermal split

Detection of a novel pigment network feature in reticulated black solar lentigo by high-resolution epiluminescence microscopy

Epiluminescence light microscopy (ELM) of pigmented skin lesions has led to a catalog of pigment network (PN) features. The objective of this study was to determine whether high-resolution ELM detects additional pigment structures not seen with conventional ELM. Epiluminescence light microscopy was performed by placing the lens of a standard light microscope directly on the skin surface, with resulting enhanced optical resolution compared with ELM systems currently in general use. Eight reticulated black solar lentigines were studied. All lesions were viewed and analyzed using dermatoscopic criteria for the PN. In addition, they were all photographed, excised, and examined histologically. Two subtypes of black solar lentigines could be distinguished using generally accepted dermatoscopic criteria for the PN. Furthermore, a new pigment structure was detected, namely, pigment spots of equal color, shape, and size, which were regularly superimposed on and juxtaposed to the PN. Clinicopathologic correlation showed these spots to represent individual hyperpigmented corneocytes. Because such cells result from physiologic excessive pigment translocation via the epidermal melanocytic unit, we called them pigmented corneocytes. Pigmented corneocytes were seen in seven of eight black solar lentigines. The ELM technique presented here allows for more detailed analysis and classification of the PN components. Pigmented corneocytes are proposed as an additional dermatoscopic criterion.

Diagnostic Significance of the Blue Hue in Dermoscopy of Melanocytic Lesions: A Dermoscopic–Pathologic Study

In epiluminescence microscopy, the perception of a blue hue is generally considered a clue to malignancy, especially in clinically equivocal melanocytic skin lesions. However, melanocytic nevi can seldom show a blue hue under dermoscopy. The aim of the current study was to evaluate the histopathologic correlates of the blue hue seen in dermoscopy, to clarify its significance and diagnostic value. From a series of 224 consecutive pigmented skin lesions submitted to surgical excision, we selected all the melanocytic skin lesions (n. 36), blue nevi excluded, characterized by the presence of a blue hue dermoscopically. In agreement with recent refinement of dermoscopic semeiology, all cases were further classified in cases showing blue areas and cases showing blue-whitish veil by experts observers blinded to the final diagnosis. Histopathologically, the series included 23 (63.9%) melanocytic nevi and 13 (36.1%) melanomas. For each lesion, several histopathologic parameters related to both epidermal and dermal alterations were assessed. Blue areas were found in 21 melanocytic nevi and 7 melanomas, whereas blue-whitish veil was found in 6 melanomas and 2 nevi. Careful dermoscopic-histopathologic correlation demonstrated that blue areas are related to the presence of large amounts of melanin pigment, either within melanophages (in the context of areas of regression) or within pigmented melanocytes in the superficial dermis. Conversely, the histopathologic correlate of the blue-whitish veil resulted in the presence of an acanthotic epidermis with compact orthokeratosis overlying large amounts of melanin in the dermis. Such melanin was found not only within melanocytes but also in large clusters of melanophages within areas of regression in the dermis. In conclusion, the majority of melanocytic lesions characterized by the presence of blue areas were histopathologically diagnosed as melanocytic nevi whereas the presence of blue-whitish veil was highly indicative of malignant melanoma diagnosis (specificity 91% vs. 9% of blue areas; sensitivity 75% vs. 25% of blue areas). Thus, these two features of blue hue under dermoscopy cannot be longer considered as synonymous in dermoscopy setting, being associated with different histopathologic alterations and different diagnostic information.

The use of digital dermoscopy for the follow-up of congenital nevi: a pilot study

One of the main problems in the management of congenital nevi is the potential risk for malignant transformation and the resulting need for follow-up examination. Dermoscopy is a noninvasive technique that has been shown to be useful for the follow-up of benign melanocytic skin lesions as well as the early diagnosis of malignant melanoma. Therefore we thought to use the digital dermoscopy (DD) technique for the follow-up of congenital nevi. For documentation purposes we registered an overview, and the following standardized dermoscopic images of every lesion: representative architectural pattern, border of the lesion, and regions of "special interest." In all instances the examination with digital dermoscopy was well tolerated by the patients and the integration of the parents to the "live" examination on the computer screen was appreciated. The follow-up was easy to perform with these standardized documents. We showed the feasibility of follow-up of congenital nevi using digital dermoscopy. Furthermore, we identified three different patterns as well as some typical structures seen in congenital nevi by DD.

Histopathologic correlates of dermoscopic criteria

The correct interpretation of dermoscopic features requires an understanding of the corresponding histopathologic correlates. This articles addresses the importance of performing an exact dermoscopic-pathologic correlation when evaluating pigmented lesions of the skin. The histopathologic structures underlying most dermoscopic criteria are extensively described.