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Melanocytic Markers (melanocytic + marker)
Selected AbstractsDNA mismatch repair protein expression and microsatellite instability in primary mucosal melanomas of the head and neckHISTOPATHOLOGY, Issue 6 2007C Marani Aims:, To examine the expression of DNA mismatch repair (MMR) proteins and the presence of microsatellite instability (MSI) in seven primary mucosal melanomas of the head and neck (MMHN). Methods and results:, Haematoxylin and eosin staining and immunohistochemical analysis for routine diagnostic markers and for MMR proteins were performed. Six cases were examined for MSI. Four cases were monomorphous and three cases were pleomorphic type MMHN. Melanocytic markers were positive in all cases. Immunoreactivity for MMR proteins was weak in normal epithelium. The neoplastic tissue in six cases showed positivity for all MMR proteins with different percentages. One case showed weak positivity for hMSH2 and hMSH6 and no immunoreactivity for hMLH1 or hPMS2. Staining intensity was higher in tumour cells than in matched normal mucosa in three cases for hMSH2 and hMLH1 and in two cases for hPMS2. None of the examined cases showed MSI. Conclusions:, Expression of hMSH2 and hMLH1 proteins was up-regulated in three cases, whereas in two cases that of hPMS2 was increased. hMSH6 expression was comparable to that of normal cells in all cases. The percentage of positive neoplastic cells and the intensity of staining seemed to be greater in pleomorphic melanomas. Six cases were MMR-proficient and microsatellite stable. [source] Clear cell sarcoma of soft tissue: diagnostic utility of fluorescence in situ hybridization and reverse transcriptase polymerase chain reactionJOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2008Choladda V. Curry A 7-year-old girl presented with pain and progressive swelling on the left plantar surface. Biopsy of a 2.5 cm mass showed nests of large round to oval neoplastic cells with abundant amphophilic to clear cytoplasm, prominent nucleoli and high mitotic activity. Occasional cells showed spindled morphology. Infrequent melanin pigment was present. Melanocytic markers (HMB45, S-100) were diffusely positive. A diagnosis of clear cell sarcoma of soft tissue (CCSS) was made, and the mass was re-excised with negative margins. 28 months later, a 1.0 cm pulmonary nodule was identified and wedge excision showed metastatic CCSS. Cytogenetics showed a complex karyotype (unbalanced translocation der(12;14)(q10;q10), additional chromosome 22 material of unknown origin). Although the CCSS translocation t(12;22)(q13;q12) was not identified, EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH). Reverse transcription polymerase chain reaction (RT-PCR) showed an EWS-ATF1 fusion transcript, confirmed by direct sequencing. CCSS requires differentiation from malignant melanoma, because of overlapping clinical presentations, sites of involvement, histomorphology, immunocytochemical profiles and ultrastructure. In many circumstances, definitive diagnosis is only possible with confirmation of the CCSS-defining translocation. [source] Clear Cell Sarcoma of Soft Tissue with Cytogenetic and Molecular AnalysesJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2006C. Vejabhuti A 7-year-old girl presented with pain and progressive swelling on the left plantar surface. Biopsy of a 2.5 cm mass demonstrated nests of large oval tumor cells with high nuclear-to-cytoplasm ratio, amphophilic to clear cytoplasm, prominent nucleoli, and brisk mitotic activity. Occasional cells showed spindled morphology. Infrequent melanin pigment was present. Melanocytic markers (HMB45, S-100) were diffusely positive. A diagnosis of clear cell sarcoma of soft tissue (CCSS) was made, and the tumor was re-excision with negative margins. 28 months later, a 1.0 cm pulmonary nodule was identified and showed CCSS. Cytogenetics demonstrated a complex karyotype (unbalanced translocation der(12;14)(p10;q10), additional chromosome 22 material of unknown origin). Although the CCSS translocation t(12;22)(q13;q12) was not identified, EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH). RT-PCR demonstrated an EWS-ATF1 fusion transcript, confirmed by direct sequencing. CCSS requires differentiation from malignant melanoma, due to overlapping clinical presentations, sites of involvement, histomorphology, immunocytochemical profiles, and ultrastructure. In many circumstances, definitive diagnosis is only possible with confirmation of the CCSS tumor-defining translocation. [source] PNL2 melanocytic marker in immunohistochemical evaluation of primary mucosal melanoma of the head and neckHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 6 2008Luc G. Morris MD Abstract Background Histologic diagnosis of mucosal melanoma of the head and neck is difficult, requiring immunohistochemical stains which are less reliable than in cutaneous lesions. PNL-2 is a novel marker that has not been examined in mucosal melanoma. Methods Nine formalin-fixed tissue sections of mucosal melanoma were stained with PNL-2, human melanoma black (HMB)-45, Melan-A, S-100, and microphthalmia transcription factor (MITF). Results Disease in all 9 patients arose from the sinonasal mucosa. Rates of diffuse positive staining with the 4 stains were PNL-2 (77.8%), HMB-45 (77.8%), Melan-A (50%), S-100 (87.5%), and MITF (40%). In 3 patients, PNL2 staining was superior to Melan-A or MITF. Conclusion We report the first characterization of PNL-2 staining in head and neck mucosal melanoma. PNL-2 demonstrates high sensitivity for mucosal melanoma, likely superior to Melan-A and MITF, and comparable to HMB-45, with specificity superior to S-100. We advocate inclusion of PNL2 as an important adjunctive marker in the evaluation of these lesions. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source] Characterization of t(6;11)(p21;q12) in a renal-cell carcinoma of an adult patientGENES, CHROMOSOMES AND CANCER, Issue 5 2007Lorenza Pecciarini Renal-cell carcinoma (RCC) constitutes a heterogeneous group of tumors with specific chromosome aberrations. Recently, a new small group of RCC, occurring in children and young adults, has been described as characterized by t(6;11)(p21;q12). It has been shown that this translocation results in the fusion of the 5, portion of the ALPHA gene (11q12) with the transcription factor gene TFEB (6p21). Herewith, we report the first complete cytogenetic and molecular characterization of a t(6;11)-positive RCC of an adult patient, a 54-year-old woman. The tumor was histologically defined as RCC with peculiar features and it was negative for epithelial markers and positive for melanocytic markers. Chromosome QFQ banding analysis of short-term cultured cells from the RCC showed t(6;11)(p21;q12) as the sole cytogenetic abnormality. The translocation was confirmed by FISH analysis. RT-PCR analysis, performed on total RNA isolated from both neoplastic and normal tissue samples, revealed an ALPHA,TFEB chimeric transcript in the tumor sample; sequencing of the RT-PCR product defined a novel TFEB gene breakpoint cluster region, broader than the one reported thus far. Western blot analysis showed a band at the expected size of wild-type TFEB in the neoplastic tissue compared to the normal sample, supporting that the fusion gene does not encode for a chimeric protein but it causes an upregulation of the wild-type TFEB. Our data contribute to define better this rare RCC type, which is typical not only of childhood but can also be found in adulthood. © 2007 Wiley-Liss, Inc. [source] The effects of gp100 and tyrosinase peptide vaccinations on nevi in melanoma patientsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2006David S. Cassarino Background:, A new approach to prevent disease recurrence in high-risk melanoma patients involves immunization with gp100 and tyrosinase peptides. This is the first study to examine the effects of such treatments on nevi. Design:, We studied biopsies of ,clinically atypical' nevi from 10 patients before and after peptide vaccination. All had a cutaneous melanoma measuring at least 1.5 mm in depth, satellite metastases, or at least one positive lymph node. We performed immunohistochemical stains for CD3, CD4, CD8, MHC-I, MHC-II, CD1a, HMB-45, MART-1, tyrosinase, bcl-2, p53, and Ki-67 (mib-1). Results:, Immunohistochemistry showed no differences in staining due to vaccination in either the immunologic or melanocytic markers. However, there was a significant increase in both p53 and bcl-2 staining, and a trend toward decreased Ki-67 staining, in the nevi post-treatment. Discussion:, The primary goal of peptide vaccinations with gp100 and tyrosinase is to activate melanoma-specific T cells in order to prevent melanoma recurrence. Nevi were studied in order to assess the effects on benign melanocytes. No significant changes in lymphocytes, langerhans cells, expression of MHC antigens, or melanocytic markers were found. The increase in p53 and bcl-2 raises the possibility that vaccination with melanocytic antigens stimulates a response in benign melanocytes. [source] CD34+ Pigmented Fibrous Proliferations: The Morphologic Overlap Between Pigmented Dermatofibromas and Bednar TumorsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005J. Chu McAllister Pigmented dermatofibrosarcoma protuberans (Bednar tumor) constitute 5,10% of all cases of dermatofibrosarcoma protuberans, and are usually considered mimics of melanocytic proliferations rather than fibrous lesions. We report two cases of pigmented fibrous proliferations that demonstrate features of both dermatofibromas and DFSP. The first case is a 19-year-old man with a three year history of a slowly growing pigmented lesion on the right arm. On clinical exam the lesion was a 7 mm firm pigmented papulonodular lesion. The second case is a 31-year-old woman with a 4,5 year history of a slowly enlarging, asymptomatic ,dark area' on the right buttock. On clinical exam the lesion is a 2 cm darkly pigmented flat nodule. Morphologically both lesions are primarily dermal proliferations of spindled cells admixed with pigmented dendritic melanocytes. The lesional cells trap collagen fibers at the periphery and there is basal cell hyperpigmentation. Adnexal structures are effaced but significant trapping of subcutaneous fat is not present. By immunohistochemistry both lesions show focal CD34 positivity but are negative for Factor XIIIa and melanocytic markers. Although overlap between dermatofibromas and DFSP is well documented in the literature, pigmented fibrous lesions with features of both entities are not well described. [source] | ||||||||||