Onychocytic Matricoma: A Clinical, Dermoscopic, and Pathological Analysis of 14 Cases.

ABSTRACT: Onychocytic matricoma (OCM) is a benign neoplasm of the nail matrix. Only 18 cases of this tumor have been reported in the literature to date. We retrospectively analyzed the clinical features of 14 patients with OCM. The most common clinical feature was longitudinal xanthopachyonychia (n = 9), followed by longitudinal leukopachyonychia (=3) and longitudinal pachymelanonychia (n = 2). The most common clinical findings identified following dermoscopy and analysis at high magnification of classical photographs were free-edge thickening of the nail plate without pitting (n = 14), longitudinal ridging (n = 7), round white clods (n = 7), white dots (n = 7), and filiform hemorrhages (n = 7), followed by oval and linear white clods (n = 5), fuzzy lateral border (n = 5), and red-purple blood clods (n = 3). Nail clipping histopathology showed a thickened nail plate with multiple, small, round-to-oval spaces. The tumor expressed immunopositivity for LEF-1. Dermoscopy of the nail plate and nail clipping histology provides useful information with regards to the differential diagnosis with subungual squamous cell carcinoma and nail melanoma. Ex vivo-in vivo correlation facilitates a better dermoscopic assessment of this unique underrecognized disease. However, the differential diagnosis between OCM and onychocytic carcinoma requires biopsy of the tumor. LEF-1 as an onychogenic marker can be used to resolve the differential diagnosis between OCM and subungual longitudinal acanthoma/seborrheic keratosis.

Outcome of pretransplant melanoma after solid organ transplantation: an observational study.

The number of patients with a history of melanoma who are awaiting a solid organ transplantation (SOT) is increasing. Few recommendations exist on the timing to transplantation after melanoma diagnosis. The aim of this study was to assess the melanoma recurrence-free survival after pretransplant melanoma (PTM). We conducted a multicenter ambispective observational study. Organ transplant recipients (OTR) with a history of PTM and complete AJCC staging were included. Thirty-seven patients (predominantly men with a renal allograft) were included. Five melanomas were in situ, 21 stage IA, 4 stage IB, 5 stage II, and 2 stage IIIB. The median post-transplantation follow-up time was 4 years. Sixty-two percent of patients were followed up more than 2 years. Recurrence-free survival since melanoma reached 89.9%, but varied significantly according to AJCC staging (P = 0.0129). Three patients presented a recurrence. Despite the rather limited sample size and a wide range of follow-up, our findings concerning the recurrence-free survival appear reassuring for in situ and stage IA PTM; accordingly, we suggest that a waiting time to transplantation is not mandatory in patients with in situ or stage IA PTM, especially whenever SOT is urgently needed. Caution is, however, needed for patients with higher stage.

Anthrenus sp. and an Uncommon Cluster of Dermatitis.

We report patients in their homes in France who had cutaneous lesions caused by Anthrenus sp. larvae during the end of winter and into spring. These lesions mimic bites but are allergic reactions to larvae hairs pegged in the skin. These lesions should be distinguished from bites of bed bugs or fleas.

Tumour-derived SPARC drives vascular permeability and extravasation through endothelial VCAM1 signalling to promote metastasis.

Disruption of the endothelial barrier by tumour-derived secreted factors is a critical step in cancer cell extravasation and metastasis. Here, by comparative proteomic analysis of melanoma secretomes, we identify the matricellular protein SPARC as a novel tumour-derived vascular permeability factor. SPARC deficiency abrogates tumour-initiated permeability of lung capillaries and prevents extravasation, whereas SPARC overexpression enhances vascular leakiness, extravasation and lung metastasis. SPARC-induced paracellular permeability is dependent on the endothelial VCAM1 receptor and p38 MAPK signalling. Blocking VCAM1 impedes melanoma-induced endothelial permeability and extravasation. The clinical relevance of our findings is highlighted by high levels of SPARC detected in tumour from human pulmonary melanoma lesions. Our study establishes tumour-produced SPARC and VCAM1 as regulators of cancer extravasation, revealing a novel targetable interaction for prevention of metastasis.

Differences in visible light-induced pigmentation according to wavelengths: a clinical and histological study in comparison with UVB exposure.

The visible light spectrum is wide, and it can be hypothesized that all the wavelengths between 400-700 nm do not induce the same photobiological effects on pigmentation. We assessed the potential pro-pigmenting effects of two single wavelengths located at both extremities of the visible spectrum: the blue/violet line (λ = 415 nm) and the red line (λ = 630 nm). We made colorimetric, clinical, and histological assessments with increasing doses of those lights on healthy volunteers. Then, we compared these irradiations to non-exposed and UVB-exposed skin. Colorimetric and clinical assessments showed a clear dose effect with the 415-nm irradiation, in both skin type III and IV subjects, whereas the 630 nm did not induce hyperpigmentation. When compared to UVB irradiation, the blue-violet light induced a significantly more pronounced hyperpigmentation that lasted up to 3 months. Histological examination showed a significant increase of keratinocyte necrosis and p53 with UVB, as compared to 415- and 630-nm exposures.