Familial multiple blue nevi

Diagnostic Imaging of Agminated Blue Lesions and Blue Lesions with Satellitosis: Case Series with a Concise Review of the Current Literature

Background: Agmination and/or satellitosis in pigmented blue lesions is a phenomenon rarely mentioned in the literature and not well known. This phenomenon can be expressed by several benign and malignant pigmented blue lesions, such as blue nevi, Spitz nevi, melanocytoma and melanoma. On this spectrum, dermoscopy, reflectance confocal microscopy (RCM) and dynamic Optical coherence tomography (D-OCT) represent non-invasive imaging technologies, which may help clinicians in the diagnosis of melanoma and non-melanoma skin cancers in daily clinical practice. Methods: Currently, in the literature there is a lack of new data about agminated blue lesions and blues lesions with satellitosis, as well as the lack of a recent and updated review of the literature about this topic. Therefore, considering that clinicians must be confident with the diagnosis of these rare skin lesions, we decided to carry out this work. Results: In this paper, four new cases of agminated pigmented cutaneous lesions were described. Moreover, a review of the current literature on this topic was performed. Conclusions: A clinical-pathological correlation is often needed to reach a correct diagnosis; currently, dermoscopy and non-invasive diagnostic techniques, such as reflectance confocal microscopy and optical coherence tomography, due to the depth of these skin lesions in the dermis, can only make a partial and limited contribution.

Blue nevi and related lesions: a review highlighting atypical and newly described variants, distinguishing features and diagnostic pitfalls

Blue nevi and related entities are a heterogenous group of congenital and acquired melanocytic tumors that includes established entities such as dendritic ("common") blue nevus and cellular blue nevus, and their numerous clinical and pathologic variants, such as deep penetrating nevus. They share several clinical and morphologic features including their blue tinctorial properties, the presence of a dermal proliferation of spindle, fusiform or ovoid cells, associated melanin pigment (both within the melanocytic tumor cells and also within macrophages) and stromal sclerosis and, at least focal positivity for HMB-45 (Gp100). Some variants, such as deep penetrating nevus, often show considerable variation in nuclear size and shape, and, as a consequence, are at risk of being misdiagnosed as melanoma by those unfamiliar with their characteristic morphologic features. The so-called malignant blue nevus is a controversial term denoting melanomas arising in association with or exhibiting some morphologic similarities to blue nevus. There are also lesions that are probably related to blue nevi, such as the recently described pigmented epithelioid melanocytoma and the neurocristic hamartomas, whose nature, biologic behavior, and relationship to the better established entities remains to be clearly established. This review aims to present a brief overview of these lesions, highlighting their pathologic characteristics, distinguishing features and potential diagnostic pitfalls, with particular emphasis on recently described entities, molecular findings, controversial areas, and approaches to diagnosis.

Blue Nevi and Related Tumors

Blue nevi and related lesions are characterized by the proliferation of dermal dendritic melanocytes. Although they share certain common clinical and histologic features, they encompass a spectrum of lesions ranging from benign melanocytic hamartomas and common blue nevi to borderline malignant pigmented epithelioid melanocytoma and aggressive malignant blue nevi. This article succinctly describes the common dermal dendritic proliferations and updates readers on newly classified entities and variants. The differential diagnosis of the main entities and strategies to distinguish them from their melanocytic and nonmelanocytic mimics is also presented.