Dendritic cells in reflectance confocal microscopy is a clue for early melanoma diagnosis in extrafacial flat pigmented melanocytic lesions

Innate Immune Cells in Melanoma: Implications for Immunotherapy

The innate immune system, composed of neutrophils, basophils, eosinophils, myeloid-derived suppressor cells (MDSCs), macrophages, dendritic cells (DCs), mast cells (MCs), and innate lymphoid cells (ILCs), is the first line of defense. Growing evidence demonstrates the crucial role of innate immunity in tumor initiation and progression. Several studies support the idea that innate immunity, through the release of pro- and/or anti-inflammatory cytokines and tumor growth factors, plays a significant role in the pathogenesis, progression, and prognosis of cutaneous malignant melanoma (MM). Cutaneous melanoma is the most common skin cancer, with an incidence that rapidly increased in recent decades. Melanoma is a highly immunogenic tumor, due to its high mutational burden. The metastatic form retains a high mortality. The advent of immunotherapy revolutionized the therapeutic approach to this tumor and significantly ameliorated the patients' clinical outcome. In this review, we will recapitulate the multiple roles of innate immune cells in melanoma and the related implications for immunotherapy.

Melasma and reflectance confocal microscopy: from baseline to treatment monitoring

Melasma is a frequent condition worldwide, and it represents one of the most challenging disorders to treat in cosmetic dermatology. One of the critical factors for treatment prognosis is the assessment of the depth and distribution of pigment within the hyperpigmented area. Nowadays, non-invasive skin imaging techniques, such as reflectance confocal microscopy (RCM), have been used to estimate pigment distribution and depth within different skin layers. This article aims to provide a systematic review of RCM applications in melasma, providing terminology and investigating characteristics of melasma at baseline and after medical and laser treatment. Our results support the recognition of two main types of melasma, epidermal and mixed type, thanks to the role of RCM in highlighting the precise pigment depth location in the skin non-invasively. RCM treatment monitoring enables the objectification of pigment variations after treatment and the identification of prognostic factors for different treatment modalities. After the era of the application of RCM as a technique applied strictly to skin cancers, additional cosmetic applications are emerging, such as the application of melasma treatment monitoring.

Concordance between reflectance confocal microscopy and histopathology for the diagnosis of acral lentiginous melanoma

BACKGROUND

Acral lentiginous melanoma (ALM) is a highly malignant and invasive type of melanoma with unique locations of onset. Its incidence is increasing and early diagnosis is challenging. Reflectance confocal microscopy (RCM) is a non-invasive technique that provides an accurate image of tissue pathology. There are few reports on the use of RCM for the assessment of ALM.

MATERIALS AND METHODS

In this retrospective study, data from 31 patients with a clinical diagnosis of ALM were collected. RCM image features were compared with histopathological findings to determine the concordance between the two methods. The sensitivity, specificity, positive predictive value, and negative predictive value of RCM for the diagnosis of ALM were evaluated.

RESULTS

RCM and histopathology findings were concordant in 29 of 31 patients (93.5%). There were no false-negative results, although there were two false positives in RCM diagnosis. The sensitivity of RCM for diagnosing ALM was 100%, specificity was 50%, positive predictive value was 93.1%, and negative predictive value was 100%.

CONCLUSIONS

RCM showed substantial concordance with histopathology in the diagnosis of ALM. It is a reliable and valuable non-invasive diagnostic tool that holds promise for the early diagnosis of ALM.

Dermatoscopic, Histological and Confocal Microscopic Analysis of a Kissing Nevus of the Penis

Kissing nevus is a congenital melanocytic neoplasm arising in those parts of the body that split at some point during embryological development (i.e., eyelid; penis), resulting in two adjacent melanocytic nevi. To date, 23 cases of kissing nevus of the penis have been described, and dermatoscopic and histological findings are available in 4/23 cases. We report a dermatoscopic, histological and confocal microscopic analysis in a new case of the kissing nevus of the penis in a 57 years old man. Dermatoscopic analysis showed large globules in the central area and a peripheral pigment network; the histological examination confirmed the presence of an intradermal melanocytic nevus with minimal junctional component and congenital features. Moreover, we reported, for the first time, confocal microscopy findings in the kissing nevus of the penis, revealing the presence of dendritic cells in correspondence with the epidermis and suggesting a state of cellular activity. Considering the clinicopathological features of the lesion, a conservative approach was adopted, and a clinical follow-up was planned after six months.