Dermoscopic and histopathologic diagnosis of equivocal melanocytic skin lesions

Abstract

BACKGROUNDDermoscopy (dermatoscopy, epiluminescence microscopy) is increasingly employed for the preoperative detection of cutaneous melanoma; dermoscopic features of pigmented skin lesions have been previously defined using histopathology as the key to the code. In a preliminary study on 10 cases evaluated by nine dermoscopists and nine histopathologists, the authors experienced that when at least two dermoscopists disagree in evaluating a melanocytic lesion, even histopathologic consultations may give equivocal results.METHODSOne hundred seven melanocytic skin lesions, consecutively excised because of equivocal clinical and/or dermoscopic features, were retrospectively examined by eight dermoscopists and eight histopathologists; the diagnostic interobserver agreement was calculated by means of the Schouten k statistics. After histopathologic consultations, all 107 lesions underwent unblinded dermoscopic re‐evaluation in order to find which dermoscopic features had given rise to histopathologic diagnostic difficulties.RESULTSThe interobserver ageement was good for both dermoscopy (k = 0.53) and histopathology (k = 0.74). Out of 48 cases evaluated by the dermoscopists in complete accordance, only 8 (16.7%) received at least one conflicting histopathologic diagnosis. Instead, among the remaining 59 cases with at least one disagreeing dermoscopic diagnosis, 21 (35.6%) received at least one disagreeing histopathologic diagnosis. The unblinded dermoscopic re‐evaluation showed that five out of seven lesions with clear‐cut regression structures were histopathologically controversial.CONCLUSIONSAt least for selected and reasonably difficult lesions, a diagnostic discrepancy among formally trained dermoscopists seems to be predictive for a diagnostic disagreement among histopathologists. Lesions showing clear‐cut regression structures are prone to give some histopathologic disagreement. Cancer 2002;95:1094–1100. © 2002 American Cancer Society.DOI 10.1002/cncr.10768

The Spectrum of Spitz Nevi

“…Among these lesions, we found that a potential source of dermoscopic overestimation was a bandlike dermal infiltrate of melanophages, a common ancillary feature of pigmented spindle-cell nevi. In fact, in 3 cases, this feature was responsible for a diffuse bluish pigmentation of the lesion, a worrisome dermoscopic feature that suggests the presence of either regression 30,31,34 or a blue-whitish veil. 23,30,31 In addition, and even more interestingly, 4 cases showed a striking dermoscopic asymmetry, which was not adequately represented on histologic sections.…”

“…Moreover, the histopathologic features of lesions with spitzoid features are often not definitive, creating substantial diagnostic interobserver disagreement. 34 Finally, when dermoscopy clearly reveals features of a Spitz nevus, sometimes the histopathologic analysis of the same lesion supports a diagnosis of a melanoma. Remarkably, the "spitzoid melanoma" does not have a distinctive dermoscopic counterpart.…”

Sclerosing Nevus with Pseudomelanomatous Features (Nevus with Regression-Like Fibrosis): Clinical and Dermoscopic Features of a Recently Characterized Histopathologic Entity

“…We have also called them ‘nevi with regression-like fibrosis’ (NRLF) [2,3,4], a term which maintains ‘regression’ as an immunologic, melanoma-specific phenomenon [5,6,7,8]. Such lesions are probably the result of minor, unnoticed trauma(s) on preexisting nevi and are histopathologically characterized by (i) an atypical junctional proliferation associated with some pagetoid spreading, (ii) significant area(s) of dermal fibrosis/sclerosis containing architecturally atypical melanocytic nests and (iii) residual nevus tissue (often with congenital-like features) around and deep into the cicatricial tissue.…”

Limitations of Histopathologic Analysis in the Recognition of Melanoma

“…In our estimation, the conceptual and practical link between dermoscopy and histopathology is strong. In 2002, Ferrara and colleagues 16 demonstrated in a study of 107 equivocal melanocytic lesions that a diagnostic discrepancy among formally trained dermoscopists seemed to predict a diagnostic disagreement among histopathologists. These data lend increasing importance to establishing a dialogue between dermoscopists and histopathologists who will probably experience similar diagnostic troubles on a given case.…”