In vivo reflectance confocal microscopy features of a melanoacanthoma

Abstract

Efforts have been expended to evaluate the reflectance confocal microscopy (RCM) features of different clinical entities in order to more thoroughly delineate benign versus malignant features. In this way, RCM can help clinicians to be more selective in regard to undertaking appropriate skin biopsies and improving their benign to malignant ratio. Herein, we report a case of a histopathologically proven melanoacanthoma, a variant of seborrheic keratosis. There are scarce reports describing the RCM features of melanoacanthoma. Our case demonstrated RCM features that were suspicious for melanoma. More RCM images of this benign entity are needed to establish definitive diagnostic criteria.

Melanoacanthoma: a potential pitfall of reflectance confocal microscopy

“…However, melanoma-specific dermoscopic criteria were identified in six of these cases, and blue-white veil and atypical dots were the most frequent features 1 . In the most recent report, Shahriari et al described a black papule with blue-black pigmentation, suspicious for nodular melanoma 3 …”

“…CM is an uncommon neoplasm histologically characterized by proliferation of epidermal keratinocytes and large dendritic melanocytes. The melanocytes are scattered throughout the tumor 3, 4, 5. The exact incidence of CM among the SK histopathological subtypes is unclear.…”

“…This benign lesion is clinically notable for its dark pigmentation and fast-radial growth, making this entity difficult to distinguish from melanoma. CM has been seldom characterized with dermoscopy and with reflectance confocal microscopy (RCM) 3 …”

Melanoacanthoma Masquerading as Melanoma: Case Reports and Literature Review

“…It demonstrates positive staining of the melanocytes in a melanoacanthoma. However, since melanoma and benign nevi also demonstrate positive staining of melanocytes with MART-1, other pathologic features observed on hematoxylin and eosin staining are necessary to confirm the diagnosis of melanoacanthoma [13,15].…”

The challenge of diagnosing seborrheic keratosis by reflectance confocal microscopy

“…Histologically, seborrheic keratosis has been classified into 6 different subtypes, including acanthotic subtype, hyperkeratotic subtype, adenoid subtype, clonal subtype, irritated subtype, and melanoacanthoma. The RCM images of each subtype may be different . Most seborrheic keratosis cases showed normal honeycomb in epidermal (Table ).…”