Nodular Lesion in Cheek With a Hair Tuft

Trichostasis spinulosa is a rarely diagnosed disorder of the pilosebaceous unit, characterized by retention of telogen hairs within the dilated follicles. A hair tuft can be seen protruding from the follicles. We present a case of trichostasis spinulosa associated with intradermal melanocytic nevi, where dermoscopy helps to identify this entity.

The density and type of MECA-79-positive high endothelial venules correlate with lymphocytic infiltration and tumour regression in primary cutaneous melanoma

Aims Tumour-infiltrating lymphocytes have prognostic value in malignant melanoma. High endothelial venules (HEVs) are specialized vessels present in lymph nodes and tertiary lymphoid organs. CCL19, CCL21 and CCR7 regulate lymphocyte migration through HEVs. The aim of our study was to correlate HEV density in cutaneous primary and metastatic malignant melanomas with clinicopathological parameters, and with CCL19, CCL21 and CCR7 mRNA expression. Methods and results High endothelial venule density was evaluated by immunohistochemistry with a specific antibody, MECA-79, and chemokine expression was evaluated by real-time PCR. MECA-79-positive vessels, covered by cuboidal (C-HEV) or flat (F-HEV)…

Complete Regression of Melanocytic Nevi: Correlation Between Clinical, Dermoscopic, and Histopathologic Findings in 13 Patients

Background: The complete regression of melanocytic tumors, confirmed by histology, has rarely been reported in the literature. It is very difficult to determine the malignant or benign nature of a regressed tumor, and on occasions, the only indication of malignancy is the subsequent development of metastasis. Material and methods: We performed a descriptive study of melanocytic nevi that had undergone complete, histologically confirmed regression prior to excision in the dermatology department of our hospital over a period of 3 years. We included only lesions in which dermoscopy performed prior to regression showed features that suggested benignity. We assessed various clinical, dermoscopic…

Atypical Phacomatosis Pigmentokeratotica as the Expression of a Mosaic RASopathy With the BRAF-Glu586Lys Mutation

Spontaneous regression of multiple melanocytic nevi after melanoma: report of 3 cases.

Complete spontaneous regression of multiple melanocytic nevi after melanoma is an extremely rare phenomenon. We report 3 cases of patients with a history of melanoma that showed regression of almost all melanocytic nevi over time. One of the patients had 2 simultaneous primary cutaneous melanomas without metastasis. In the other 2 patients, regression of the melanocytic nevi was seen after the development of metastasis in lymph nodes. These patients had spontaneously developed an efficient immune response against melanocytes, and they would represent paradigmatic examples of the spontaneous immune responses in melanoma patients. Better understanding of the mechanisms involved in the complet…

CXCR3 chemokine receptor immunoreactivity in primary cutaneous malignant melanoma: correlation with clinicopathological prognostic factors.

A role for CXCR3, the receptor for chemokines Mig, IP-10 and interferon-inducible T cell alpha-chemoattractant, in tumour cell migration during melanoma progression has been proposed.To analyse CXCR3 expression in primary cutaneous malignant melanomas and its comparison with clinicopathological and prognostic factors.A retrospective immunohistochemical study was carried out on formalin-fixed paraffin-wax-embedded sections from 82 patients with primary invasive cutaneous melanomas, with a monoclonal antibody to CXCR3 (clone 49801.111; RD Systems). Immunoreactivity was semiquantitatively evaluated: labelling intensity (0, absent; 1, weak; 2, moderate; 3, strong) multiplied by the percentage o…

Progressive depigmentation of a melanocytic lesion: a dermoscopic challenge for melanoma diagnosis.

Sexual selection and the chemical signal design of lacertid lizards

Animal signals can differ considerably in complexity and composition, even among closely related species. Work on vocal and visual signals has revealed how sexual selection can elaborate signals relevant in mate choice or rival assessment, but few studies have investigated this process in chemical signals. In this study, we correlated chemical signalling diversity and richness with degree of sexual dimorphism in a data set of 60 species of the lizard family Lacertidae. The femoral glands of male lacertid lizards exude waxy secretions, of which the lipophilic fraction is known to function in chemical communication. We determined the composition of the gland secretions using gas chromatograph…

Going underground: short- and long-term movements may reveal the fossorial spatial ecology of an amphisbaenian

[Background]: The movement and spatial ecology of an animal depends on its morphological and functional adaptations to its environment. In fossorial animals, adaptations to the underground life help to face peculiar ecological challenges, very different from those of epigeal species, but may constrain their movement ability.

Enseñanza de las ciencias : revista de investigación y experiencias didácticas

Resumen basado en el de la revista El concepto de campo presenta una especial relevancia en Física. Sin embargo, su enseñanza ofrece una serie de dificultades y deficiencias que fueron analizadas por los autores en una investigación previa.De acuerdo con este análisis y la investigación de otros autores se han elaborado algunas propuestas para la introducción de este concepto en educación secundaria. En este estudio se presentan las directrices de la anterior propuesta puesta en práctica en una clase y evaluada después. Los resultados fueron analizados mediante diferentes instrumentos y comparados con los obtenidos por estudiantes que seguían programas oficiales. Cataluña ESP

Clinicopathological and immunohistochemical analysis of 20 cases of Merkel cell carcinoma in search of prognostic markers.

Aims:  To evaluate the clinicopathological and immunohistochemical characteristics of Merkel cell carcinoma (MCC) in an attempt to find new, potentially significant, prognostic markers. Methods and results:  Clinical data and follow-up, histopathological features (pattern, cell size, thickness, mitoses, vascular invasion, lymphocytic infiltration) and immunohistochemical detection [CK20, thyroid transcription factor (TTF-1), chromogranin A, synaptophysin, p53, Ki67, Fli-1, CD99, c-Kit] were evaluated in 20 cases of MCC. Fli-1 and CD99 were detected in 90% and 55% of cases, respectively. Tumour size > 30 mm, stage II, ‘absent’ lymphocytic infiltration, and the presence of > 50% of Ki67+ tumo…

Descriptive Dermoscopic Study of Depigmentation in Melanocytic Nevi Without a Visible Halo

Background and objectives: There are few cases described in the literature in which depigmentation of melanocytic nevi occurs without the appearance of halos. The aim of this study was to analyze the correlation between clinical and dermoscopic findings and to assess the usefulness of dermoscopy to identify possible markers of complete regression in melanocytic lesions. Materials and methods: A prospective, observational, descriptive study of 77 melanocytic lesions in 52 patients was undertaken over a 5-year period. Melanocytic lesions from patients who underwent periodic follow-up in the digital dermoscopy unit were analyzed if they had exhibited partial or total, permanent depigmentation …

Estudio descriptivo dermatoscópico de los nevos melanocíticos con despigmentación sin halo clínico

Resumen Introduccion la despigmentacion de nevos melanociticos sin halo perilesional se ha descrito de forma excepcional en la literatura. Material y metodos estudio observacional, descriptivo y prospectivo de 77 lesiones melanociticas correspondientes a 52 pacientes, llevado a cabo durante un periodo de 5 anos. Se han analizado las lesiones melanociticas de pacientes revisados periodicamente en la unidad de dermatoscopia digital que habian sufrido una despigmentacion permanente, ya fuera total o parcial, pero sin presentar clinicamente un halo blanquecino alrededor de los mismos. El objetivo fue estudiar la correlacion entre los hallazgos clinicos y dermatoscopicos a estudio, y establecer …