Dermoscopic features of melanomas associated with MC1R variants in Spanish CDKN2A mutation carriers.

BACKGROUND: The presence of at least one MC1R gene variant is associated with a reduction in age at melanoma diagnosis in families with CDKN2A mutations. OBJECTIVES: To describe dermoscopic features of early melanoma in CDKN2A gene mutation-positive Spanish individuals and to evaluate the possibility of a correlation between particular dermatoscopic pattern and MC1R gene variants. METHODS: Patients in whom a melanoma was diagnosed during specific follow up of high-risk individuals carrying CDKN2A mutations (with familial or personal history of previous melanoma) were included in this study. The decision to remove such melanomas was taken on the basis of history, clinical and dermoscopic evaluations including total body photography and digital dermoscopy. RESULTS: Of the nine patients included in this study, three were noncarriers of the red hair MC1R polymorphism, three patients had one red hair MC1R polymorphism and three patients had two red hair MC1R polymorphisms. On dermoscopic analysis of suspect melanocytic lesions we found that the mean +/- SD ABCD total dermoscopy score (TDS) was significantly higher in noncarriers of red hair MC1R polymorphisms than in carriers of two MC1R gene red hair variants (6.8 +/- 0.4 vs. 4.4 +/- 0.9; P = 0.014). CONCLUSIONS: Early melanomas in patients with two MC1R red hair variants may be difficult to diagnose definitively by dermoscopy because, in our limited experience, they show fewer colours and structures and have a lower TDS. In such melanomas, subtle atypical vessels and other changes detected by digital image follow up may be useful to confirm the diagnosis of melanoma. An integrated approach including clinical history and dermoscopic data (also considering additional information, such as the presence of atypical vessels) should be utilized in evaluating these high-risk patients. Further studies are necessary to confirm our suggestion.

Dermoscopy of skin lesions in two patients with xeroderma pigmentosum.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare disorder produced by a genetic defect in the repair of DNA damage caused by ultraviolet radiation. The early diagnosis of malignant skin tumours is crucial in the survival of patients with XP, but this is not easy even for experienced dermatologists due to the presence of a high number of actinic lesions. Dermoscopy is a new diagnostic method that increases the diagnostic accuracy for skin tumours. OBJECTIVES: To describe the clinical and dermoscopic features of different benign and malignant lesions [focusing on malignant melanoma, basal cell carcinoma (BCC) and benign melanocytic naevi] in two patients with XP. METHODS: Three dermatologists with experience in pigmented skin lesions and dermoscopy examined two siblings with XP over a period of 54 months. Diagnosis of skin tumours was obtained using clinical examination and dermoscopy with 10-fold magnification and digital images. All the tumours with criteria of malignancy were excised for further histopathological analyses. RESULTS: Multiple skin tumours showing some degree of pigmentation were detected in the patients. Clinical and dermoscopic examination allowed the discrimination of four melanomas (three of them in situ), 26 BCCs and five dysplastic naevi from other pigmented skin lesions. The features and parameters previously described for dermoscopy were shown to be appropriate for the recognition of tumours in our patients with XP. Generalized actinic lentigos were distinguished from BCCs by the presence of a delicate brown pigmented network. Fine vessels from poikiloderma were differentiated from the arborizing telangiectasia of BCC. CONCLUSIONS: The dermoscopic findings in the tumours were similar to those previously described in patients not affected by XP. Diagnosis by dermoscopic pattern analyses allowed a correct classification of malignant tumours in these cases.

Depósitos del complejo de ataque de membrana en la alopecia areata / Membrane attack complex deposits in alopecia areata

El sistema del complemento es un complejo formado por más de 28 proteínas plasmáticas, cuya activación secuencial en cascada tiene como resultado un producto final, el complejo de ataque de membrana (MAC ó C5b-9) y unas fracciones protéicas derivadas de la fragmentación de los diferentes componentes del complemento. Estos productos de activación del complemento, además de desarrollar diferentes funciones biológicas, se han implicado en la patogenia de diversas enfermedades autoinmunes, incluso en algunas de ellas se ha demostrado que el grado de activación del sistema del complemento está relacionado con la actividad del proceso. Objetivo de estudio: Hasta el momento no se han realizado estudios similares en la alopecia areata (AA), por lo cual el objetivo de este trabajo fue detectar la posible existencia de depósitos de MAC en biopsias cutáneas de AA. Material y métodos: Para ello dispusimos de 16 muestras: 9 de ellas pertenecientes al borde de placas alopécicas de cuero cabelludo de pacientes con diferentes formas clínicas de AA, seis, a diferentes áreas pilosas de individuos control aparentemente sanos y una, a cuero cabelludo de otro paciente control afecto de lupus eritamatoso discoide (LED). La técnica utilizada fue el sistema de inmunodetección biotina-estreptavidina (Bio.Genex) y los anticuerpos monoclonales C5b-9 de Dakopatts (Dinamarca). Resultados: En 8 de 9 biopsias de AA, se hallaron depósitos de MAC en la membrana basal (MB) de muchos folículos, fundamentalmente en la porción inferior y en el promontorio. Respecto a los controles, solo en 2 de las 6 biopsias de piel normal se detectaron depósitos de MAC en la zona de la MB adyacente a la glándula sebácea y en el LED, se observaron depósitos densos de MAC a lo largo de la MB de prácticamente todos los folículos pilosos observados. Conclusión: Los depósitos de MAC parecen ser más frecuentes en las lesiones de AA que en piel normal, pero menos intensos que en el LED. Por tanto, podríamos decir que probablemente el MAC está implicado en la patogenia de la AA y quizá también interviene en el desarrollo normal del ciclo folicular (AU)