The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Martin C Mihm - One of the best experts on this subject based on the ideXlab platform.
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Unusual variants of malignant Melanoma
Modern Pathology, 2006Co-Authors: Cynthia M Magro, A Neil Crowson, Martin C MihmAbstract:A potential diagnostic pitfall in the histologic assessment of Melanoma is the inability to recognize unusual Melanoma variants. Of these, the more treacherous examples include the desmoplastic Melanoma, the nevoid Melanoma, the so-called ‘minimal-deviation Melanoma,’ Melanoma with prominent pigment synthesis or ‘animal-type Melanoma,’ and the malignant blue nevus. Also problematic are the unusual phenotypic profiles seen in vertical growth phase Melanomas; these include those tumors whose morphological peculiarities mimic cancers of nonmelanocytic lineage and those Melanomas that express aberrant antigenic profiles not commonly associated with a melanocytic histogenesis. Metaplastic change in Melanoma, balloon cell Melanoma, signet-ring cell Melanoma, myxoid Melanoma, small cell Melanoma and rhabdoid Melanoma all have the potential to mimic metastatic and primary neoplasms of different lineage derivations. Abnormal immunohistochemical expression of CD 34, cytokeratins, epithelial membrane antigen, and smooth muscle markers as well as the deficient expression of S100 protein and melanocyte lineage-specific markers such as GP100 protein (ie HMB-45 antibody) and A103 (ie Melan-A) also present confusing diagnostic challenges. In this review, we will discuss in some detail certain of these novel clinicopathologic types of Melanoma, as well as the abnormal phenotypic expressions seen in vertical growth phase Melanoma.
K F Helm - One of the best experts on this subject based on the ideXlab platform.
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Malignant Melanoma with clinical and histologic features of Merkel cell carcinoma.
Journal of the American Academy of Dermatology, 1994Co-Authors: N S House, F Fedok, M E Maloney, K F HelmAbstract:We describe a patient with malignant Melanoma that resembled a Merkel cell carcinoma both clinically and histologically. Immunohistochemical studies showed focally positive staining with S-100 protein and strongly positive staining with HMB-45. Ultrastructural study confirmed the diagnosis by demonstrating premelanosomes and melanosomes. Although the tumor appeared to be clinically unimpressive, it was a deep Melanoma with a Breslow level of 3.8 mm that necessitated aggressive treatment. Small cell Melanoma must be considered in the differential diagnosis of small cell tumors, which also includes lymphoma, eccrine carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. The diagnosis of amelanotic Melanoma, including the small cell variant, may require electron microscopic studies.
Cynthia M Magro - One of the best experts on this subject based on the ideXlab platform.
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Unusual variants of malignant Melanoma
Modern Pathology, 2006Co-Authors: Cynthia M Magro, A Neil Crowson, Martin C MihmAbstract:A potential diagnostic pitfall in the histologic assessment of Melanoma is the inability to recognize unusual Melanoma variants. Of these, the more treacherous examples include the desmoplastic Melanoma, the nevoid Melanoma, the so-called ‘minimal-deviation Melanoma,’ Melanoma with prominent pigment synthesis or ‘animal-type Melanoma,’ and the malignant blue nevus. Also problematic are the unusual phenotypic profiles seen in vertical growth phase Melanomas; these include those tumors whose morphological peculiarities mimic cancers of nonmelanocytic lineage and those Melanomas that express aberrant antigenic profiles not commonly associated with a melanocytic histogenesis. Metaplastic change in Melanoma, balloon cell Melanoma, signet-ring cell Melanoma, myxoid Melanoma, small cell Melanoma and rhabdoid Melanoma all have the potential to mimic metastatic and primary neoplasms of different lineage derivations. Abnormal immunohistochemical expression of CD 34, cytokeratins, epithelial membrane antigen, and smooth muscle markers as well as the deficient expression of S100 protein and melanocyte lineage-specific markers such as GP100 protein (ie HMB-45 antibody) and A103 (ie Melan-A) also present confusing diagnostic challenges. In this review, we will discuss in some detail certain of these novel clinicopathologic types of Melanoma, as well as the abnormal phenotypic expressions seen in vertical growth phase Melanoma.
Rosa M. Martí - One of the best experts on this subject based on the ideXlab platform.
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Small cell Melanoma and ulceration as predictors of positive sentinel lymph node in malignant Melanoma patients.
Melanoma research, 2004Co-Authors: Francisco Cuellar, Antonio Vilalta, Ramón Rull, Sergi Vidal-sicart, J. Palou, P.j. Ventura, E. Pous, L. Quinto, Joseph Malvehy, Rosa M. MartíAbstract:Malignant Melanoma (MM) early lymph node (LN) metastasis usually appears first in the sentinel LN (SLN). Breslow thickness is the main factor considered in the selection of patients to be submitted to SLN biopsy. The present study aimed to describe other independent prognostic factors useful in SLN candidate selection. During one year, 94 MM patients (90 primary cutaneous MM with Breslow thickness > or = 0.76 mm, and four cutaneous relapses), were submitted to SLN biopsy in the Melanoma Unit at the Hospital Clinic, Barcelona, Spain. The prognostic factors studied were: Breslow thickness, Clark's level of invasion, mitotic rate, cellular type (small, epithelioid, fusocellular, sarcomatoid), vertical growth phase, regression > 50%, severe vascularization, infiltrate (lymphocytic, plasmocytic), ulceration, neurotropism, intravascular/intraneural invasion, protein p16 expression and recurrence. Nineteen SLN (20.2%) were positive and 75 (79.8%) negative. No positive SLN occurred in MM with Breslow thickness < or = 1.0 mm. Breslow thickness > or = 2 mm (P = 0.005), severe vascularization (P = 0.005), small cell (P = 0.000) and ulceration (P = 0.005) were significant prognostic factors by univariate analysis. Small cell (P = 0.008) and ulceration (P = 0.05) were also significant prognostic factors in a multivariate analysis. The probability of finding a positive SLN for small cell was 56.9% [95% confidence interval (CI), 26.8-82.6%]. The probability of positive SLN for ulceration was 35.5% (95% CI, 14.2-64.7%). For small cell and ulceration together the probability increased to 86.3% (95% CI, 54.3-97.1%). The results of this study corroborated ulceration as a prognostic factor for SLN candidate selection and for the first time we have described small cell Melanoma morphology as a significant factor associated with positive SLN.
N S House - One of the best experts on this subject based on the ideXlab platform.
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Malignant Melanoma with clinical and histologic features of Merkel cell carcinoma.
Journal of the American Academy of Dermatology, 1994Co-Authors: N S House, F Fedok, M E Maloney, K F HelmAbstract:We describe a patient with malignant Melanoma that resembled a Merkel cell carcinoma both clinically and histologically. Immunohistochemical studies showed focally positive staining with S-100 protein and strongly positive staining with HMB-45. Ultrastructural study confirmed the diagnosis by demonstrating premelanosomes and melanosomes. Although the tumor appeared to be clinically unimpressive, it was a deep Melanoma with a Breslow level of 3.8 mm that necessitated aggressive treatment. Small cell Melanoma must be considered in the differential diagnosis of small cell tumors, which also includes lymphoma, eccrine carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. The diagnosis of amelanotic Melanoma, including the small cell variant, may require electron microscopic studies.