Search results for "Skin Neoplasm"

Perineural pattern of aggregation of cellular blue nevus: probable histoarchitectural reminiscence of histogenesis.

2008

A striking feature of cellular blue nevus consists in the presence, in its histologic picture, of numerous hypertrophic nerves and nerve-like figures, positive for histochemical and immunohistochemical methods for nerve fibers and myelin sheaths. These findings, first described in Masson's original article and repeatedly highlighted in the past for their possible histogenetic significance, are currently considered as merely coincidental. However, the thin conventional histologic sections, catching only short tracts of the nerves, preclude a correct observation of their route and do not allow us to verify if there is an architectural relationship between them and the nevus as a whole. With t…

Study of the immunophenotype of the inflammatory cells in melanomas with regression and halo nevi.

2015

Abstract The pathogenesis and prognostic implications of regression in melanoma are not well understood. It has traditionally been considered an immunologically mediated phenomenon. Improvement in the knowledge of the mechanisms that lead to regression may prove to be of great value in an era in which treatments oriented to the augmentation of the host's immunity against melanoma have demonstrated excellent clinical results. This study was designed to improve the understanding of the mechanisms underlying melanoma regression and the differences between similar situations in benign melanocytic nevus. The study sample consisted of 77 lesions: 62 melanomas and 15 halo nevi. The following marke…

Comparative expression of cyclooxygenase 2 and Ki67 in amelanotic and conventional oral melanomas

2020

Background Oral melanomas have some histopathological resemblance with its cutaneous counterpart; however, an aggressive behavior is more common in tumors that occur in the oral cavity. Several markers have been suggested as indicative of tumoral progression and aggressiveness, such as cyclooxygenase 2 (COX-2) and Ki67. Material and Methods In this study, we have compared the expression of COX-2 and Ki67 in a series of amelanotic (n=7) and melanotic oral melanomas (n=22). The cases were selected from 4 pathology laboratories and submitted to the immunohistochemical (IHC) reactions. We analyzed the IHC staining based on a qualitative – using visual scores; and a computer-assisted method (qua…

Nonepithelial skin tumors with multinucleated giant cells

2013

Recognition of the different types of multinucleated giant cells in neoplastic and pseudotumoral lesions of the skin may be helpful in the differential diagnosis of these tumors. In this review, we will analyze the different types of multinucleated giant cells that can be found in nonepithelial cutaneous tumors and, more importantly, the clinicopathological context in which they are found. Touton giant cells are typically present in juvenile xanthogranuloma, necrobiotic xanthogranuloma, and some subtypes of xanthomas. Giant cells with a ground glass appearance are typically present in the solitary reticulohistiocytoma and multicentric reticulohistiocytosis. Osteoclast-like cells are found i…

Reply to “Primary cutaneous biphasic sarcomatoid basal cell carcinoma with myoepithelial carcinoma differentiation. Is it a new variant of sarcomatoi…

2020

Primary cutaneous plasmacytosis in a child. Is this a new entity?

2002

Plasma cell proliferations represent a heterogeneous spectrum of disorders. A 7-year-old Caucasian female had suffered an asymptomatic eruption on the trunk for 4 years. Physical examination revealed a plaque with scattered red-brown papules and nodules. Chemical analysis revealed normal proteinaemia. Histological examination of biopsy specimens showed dense perivascular and periadnexal infiltrate, consisting largely of plasma cells, in the superficial and deep dermis. Immunohistochemical study showed that many cells of the infiltrate were CD20 positive. The plasma cells expressed kappa and lambda light chains. The girl's status (age; absence of hypergammaglobulinaemia, lymphadenopathy and …

Dermatofibrosarcoma protuberans: a comprehensive review and update on diagnosis and management

2013

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial tumor characterized by high rates of local recurrence and low risk of metastasis. DFSP occurs most commonly on the trunk and proximal extremities, affects all races, and often develops between the second and fifth decade of life. The tumor grows slowly, typically over years. Histologically, several variants of DFSP have been described and should be well characterized to avoid misdiagnosis with other tumors. These include pigmented (Bednar tumor), myxoid, myoid, granular cell, sclerotic, atrophic DFSP, giant cell fibroblastoma, and DFSP with fibrosarcomatous areas. Of all these variants, only the DFSP with fibrosarcomatous areas is…

Primary plasmacytoma of the skin.

1996

Primary plasmacytoma of the skin without evidence of bone marrow plasmacytosis is a rare disorder belonging to the heterogenous spectrum of plasma cell neoplasms. With immunohistochemical techniques, differentiation from benign plasma cell aggregates can be accomplished by demonstrating the monoclonality of tumor cells. We describe a patient in whom a solitary primary cutaneous plasmacytoma developed on the left thigh. Immunohistochemically, plasma cells showed restriction of immunoglobulin lambda-chain expression. Underlying multiple myeloma was excluded by serum protein and immunoglobulin electrophoresis, roentgenographic skeletal survey, and bone marrow biopsy. The tumor responded well t…

Acquired IFNγ resistance impairs anti-tumor immunity and gives rise to T-cell-resistant melanoma lesions

2016

Melanoma treatment has been revolutionized by antibody-based immunotherapies. IFNγ secretion by CD8+ T cells is critical for therapy efficacy having anti-proliferative and pro-apoptotic effects on tumour cells. Our study demonstrates a genetic evolution of IFNγ resistance in different melanoma patient models. Chromosomal alterations and subsequent inactivating mutations in genes of the IFNγ signalling cascade, most often JAK1 or JAK2, protect melanoma cells from anti-tumour IFNγ activity. JAK1/2 mutants further evolve into T-cell-resistant HLA class I-negative lesions with genes involved in antigen presentation silenced and no longer inducible by IFNγ. Allelic JAK1/2 losses predisposing to …

Effect of estrogen in malignant melanoma

2021

Background Melanoma is associated with poor prognosis in its advanced stages. Potential influence of estrogen and its metabolites on melanoma growth has been suggested. Aims The objective of this review was to provide an overview on the evidence related to estrogen in malignant melanoma. Materials and methods Literature search using PubMed, Google Scholar and relevant cross-references of the retrieved articles was performed to review relevant published articles related to estrogen and its effects in malignant melanoma. Results Effect of estrogen signaling on a tissue largely depends on the relative expression of estrogen receptors (ER) α and β. Gender differences in melanoma may be explaine…