Melanoma on chronically sun-damaged skin: Lentigo maligna and desmoplastic melanoma.

There are multiple, genetically distinct pathways that give rise to melanoma. Melanomas on sun-damaged skin (MSDS), including lentigo maligna and desmoplastic melanoma, have distinct genetic profiles and are uniquely linked to chronic ultraviolet exposure. In this article, we discuss the etiologies of lentigo maligna and desmoplastic melanoma, emerging diagnostic adjuncts that might be helpful for accurately identifying these lesions, and the clinical relevance of their frequent co-occurrence. We present unique and overlapping features of these entities and discuss challenges in MSDS management, including margin assessment, excision, and the potential role of nonsurgical therapy. Last, we address the role of immunotherapy in invasive disease. Understanding MSDS as distinct from melanoma arising on intermittently sun-exposed or sun-protected skin will ultimately help optimize patient outcomes.

Reflectance confocal microscopy features of melanomas on the body and non-glabrous chronically sun-damaged skin.

BACKGROUND: Melanoma remains a challenge to diagnose, especially when appearing on the background of chronically sun-damaged skin (CSDS). Our goal was to identify and quantify the reflectance confocal microscopy (RCM) features of melanoma on non-facial CSDS. METHODS: Included lesions were biopsy-proven melanomas, from anatomic sites other than the face, neck, scalp and acral skin, with histopathologic finding of solar elastosis in the underlying dermis. All included lesions underwent clinical, dermoscopic and RCM imaging, obtained in a standardized fashion, prior to biopsy. All images were retrospectively analyzed by four observers. RESULTS: We identified 33 melanomas from 33 patients with 63.6% male patients and overall mean age of 72.8 years. The salient RCM features included an atypical honeycomb or disarranged epidermal pattern (81.8%), pagetoid infiltration of the epidermis by both round and/or dendritic melanocytes (100%), focal proliferation of predominantly dendritic melanocytes as sheets (78.8%), foci with non-edged papillae (84.8%), junctional thickening (60.6%), areas of irregular ring or meshwork pattern (78.8%), and underlying thickened collagen bundles (51.5%). CONCLUSION: Non-facial CSDS melanomas share features similar to other melanoma types including pagetoid cells and non-edged papillae. The focal proliferation of dendritic pagetoid cells in sheets is similar to that seen in facial CSDS melanomas.

Clinical and dermoscopic characteristics of melanomas on nonfacial chronically sun-damaged skin.

BACKGROUND: Melanomas on chronically sun-damaged skin (CSDS) can be difficult to identify and often manifest morphologic features that overlap with benign lesions. OBJECTIVE: We describe and analyze the clinical and dermoscopic characteristics of melanomas on nonfacial CSDS. METHODS: Melanoma cases on nonfacial CSDS were retrospectively identified from the biopsy specimen logs of 6 melanoma clinics. Clinical and dermoscopic images were combined into 1 database. Demographics, clinical, dermoscopic, and histopathologic information were analyzed. Descriptive frequencies were calculated. RESULTS: One hundred eighty-six cases met the inclusion criteria: 142 melanomas in situ (76%) and 39 invasive (21%; mean thickness, 0.49 mm). Lentigo maligna was the most common histopathologic subtype (n = 76; 40.9%). The most frequent dermoscopic structures were granularity (n = 126; 67.7%) and angulated lines (n = 82; 44%). Vascular structures were more frequent in invasive melanomas (56% vs 12% of in situ melanomas). Most manifested 1 of 3 dermoscopic patterns: patchy peripheral pigmented islands, angulated lines, and tan structureless with granularity pattern. LIMITATIONS: This was a retrospective study, and evaluators were not blinded to the diagnosis. In addition, interobserver concordance and sensitivity and specificity for dermoscopic structures were not evaluated. CONCLUSION: Outlier lesions manifesting dermoscopic structures, such as granularity, angulated lines, or vessels and any of the 3 described dermoscopic patterns should raise suspicion for melanoma.

Erosive Pustular Dermatosis of the Scalp in a Patient With Vitiligo Successfully Treated With Topical Antibiotics.

Erosive pustular dermatosis of the scalp is a rare inflammatory skin disorder that most commonly affects the elderly with androgenic alopecia. It is characterized by painless crusted erosions that usually appear following a traumatic event. It has been associated with several autoimmune diseases and commonly responds to high-potency topical steroids.This report presents a rare case of erosive pustular dermatosis of the scalp in an 84-year-old man who presented to our clinic.

5-Fluorouracil "Chemowraps" in the Treatment of Multiple Actinic Keratoses: A Norwich Experience.

INTRODUCTION: Topical 5-fluorouracil (5-FU) has been used to treat actinic keratosis for decades. It has been an important and effective treatment which the patient can self-administer, but is limited by the surface area of skin to be treated (according to the manufacturer's guidelines) of 500 cm(2). Other topical treatments can be painful, or require hospital/health care professional input. The use of 5-FU under occlusion (chemowraps) for large areas of sun-damaged skin on the arms or legs has been described and is a potentially useful treatment option. We describe our experiences with this technique in the Norfolk and Norwich University Hospital Dermatology Department (Norwich, UK). METHODS: Five patients were recruited into this pilot study. Topical 5-FU was applied to sun-damaged limbs under occlusion, and reviewed weekly for response, and local or systemic side effects. Treatment duration was 12-14 weeks. Clinical photography was undertaken prior to, during, and after treatment to document response. RESULTS: We show that there was substantial clinical improvement in the treated skin in our patients. Experienced dermatologists reviewed all the patients, and documented the changes photographically, and by counting lesions. All patients were satisfied with their treatment regimen, and also with the end result; although two did not complete the treatment regimen due to complications not directly attributable to the treatment. CONCLUSION: Topical 5-FU under occlusion (chemowraps) may be a valid treatment option for large areas of sun-damaged skin with field cancerization changes, due to low systemic and local toxicity, and acceptability to patients.