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Featured researches published by Omar Sangüeza.


American Journal of Dermatopathology | 1992

Evolution of B-cell Lymphoma from Pseudolymphoma A Multidisciplinary Approach Using Histology, Immunohistochemistry, and Southern Blot Analysis

Omar Sangüeza; Sandhya Yadav; Clifton R. White; Rita M. Braziel

Cutaneous B-cell lymphomas are rare neoplasms that can present as lesions involving solely the skin or develop in association with a systemic lymphoma. Histologically they are often difficult to differentiate from pseudolymphomas, and the use of immunohistochemistry may be necessary to correctly classify them. We report a study of multiple skin lesions in a patient who initially presented with multiple pseudolymphomas, apparently associated with an immune response to the dye of his tattoos. Over a period of 4 years his skin lesions evolved from histologically benign and immunologically polyclonal pseudolymphomas to a histologically malignant and immunologically monoclonal B-cell large cell lymphoma. Genotypic analysis with a probe for the heavy-chain immunoglobulin gene demonstrated the presence of clonal B-cell populations in all of the pseudolymphoma biopsy samples as well as in the subsequent lymphoma tissue samples, with a pattern of clonal bands suggestive of evolution of the B-cell clones. These findings suggest that the development of B-cell lymphoma in this patient was related to a persistent abnormal immune response to the chronic antigenic stimulus of the dye of the tattoo. The presence of clonal B-cell populations in pseudolymphoma by Southern blot analysis may be useful in predicting those patients who will subsequently develop overt lymphoma.


Journal of The American Academy of Dermatology | 1995

Necrolytic migratory erythema without glucagonoma in patients with liver disease

M. Peter Marinkovich; C Rafael Botella; Joel Datloff; Omar Sangüeza

Abstract Background: Necrolytic migratory erythema (NME) is an uncommon inflammatory dermatosis with a distinct clinical and histologic appearance. NME is usually associated with glucagonoma. Only a few cases of NME in the absence of glucagonoma have been previously reported. Objective: We sought to understand further the pathogenesis of NME by analyzing data from three patients. Methods: Three patients were examined both clinically and histopathologically. Results: Each patient had an extensive erythematous scaling eruption in intertriginous, perioral, and acral areas, and a markedly red, smooth tongue. Skin biopsy specimens showed confluent parakeratosis, epidermal pallor, papillary edema, and a lymphohistiocytic infiltrate. Two patients had alcoholic liver disease and one had liver dysfunction as a result of hemochromatosis. Serum albumin level was depressed, and liver enzyme values were increased in all three patients. Glucagonoma was undetectable in these patients. Conclusion: In the absence of glucagonoma, hepatocellular dysfunction and hypoalbuminemia appear to be the most common factors associated with NME.BACKGROUND Necrolytic migratory erythema (NME) is an uncommon inflammatory dermatosis with a distinct clinical and histologic appearance. NME is usually associated with glucagonoma. Only a few cases of NME in the absence of glucagonoma have been previously reported. OBJECTIVE We sought to understand further the pathogenesis of NME by analyzing data from three patients. METHODS Three patients were examined both clinically and histopathologically. RESULTS Each patient had an extensive erythematous scaling eruption in intertriginous, perioral, and acral areas, and a markedly red, smooth tongue. Skin biopsy specimens showed confluent parakeratosis, epidermal pallor, papillary edema, and a lymphohistiocytic infiltrate. Two patients had alcoholic liver disease and one had liver dysfunction as a result of hemochromatosis. Serum albumin level was depressed, and liver enzyme values were increased in all three patients. Glucagonoma was undetectable in these patients. CONCLUSION In the absence of glucagonoma, hepatocellular dysfunction and hypoalbuminemia appear to be the most common factors associated with NME.


Journal of The American Academy of Dermatology | 1993

Immunophenotypic and genotypic analysis in cutaneous lymphoid hyperplasias

Elisabeth Hammer; Omar Sangüeza; Pan Suwanjindar; Clifton R. White; Rita M. Braziel

BACKGROUND The clinical utility of immunophenotyping and Southern blot analysis in the evaluation of patients with cutaneous lymphoid hyperplasia (CLH) is controversial. OBJECTIVE Our purpose was to determine whether adjunctive immunophenotyping and Southern blot analysis are of diagnostic and prognostic value in patients with CLH. METHODS Immunophenotyping was performed on skin biopsy specimens from 26 patients with a routine histologic diagnosis of CLH. Southern blot analysis for immunoglobulin (Ig) gene rearrangements was done on 13 of 26 cases. RESULTS Twenty-four of 26 patients had polyclonal CLH on immunophenotyping: 2 of 26 had monoclonal lymphoma. Two of 11 patients with polyclonal CLH studied by Southern blot analysis had clonal Ig gene rearrangements. In both, lymphoma developed within 1 to 6 years; comparison of CLH and malignant lymphoma demonstrated overlapping and different clonal bands. Two additional patients with polyclonal CLH developed lymphoma. No clonal gene rearrangements were detected in the CLH or lymphoma from one; the other was not studied. CONCLUSION Immunophenotyping will identify some patients with lymphoma with nondiagnostic histologic features. Southern blot analysis will predict some patients with polyclonal CLH in whom malignant lymphoma will develop and who may benefit from definitive therapy.


American Journal of Dermatopathology | 1996

Epidermotropically metastatic breast carcinomas: Rare histopathologic variants mimicking melanoma and Paget's disease

Luis Requena; Evaristo Sánchez Yus; Cristina Núñez; Clifton R. White; Omar Sangüeza

Epidermotropic metastases from internal malignancies are exceedingly rare. We report two examples of epidermotropic metastatic breast carcinoma with striking intraepidermal involvement. The first case mimicked melanoma because the neoplastic cells contained melanin and were disposed both as single units and as nests at the dermoepidermal junction and throughout the epidermis. In the second case, the neoplastic cells were seen as isolated neoplastic cells with large, pale cytoplasm scattered throughout the epidermis, closely resembling extramammary Pagets disease. Immunohistochemical studies in both cases demonstrated the epithelial nature of intraepidermal neoplastic cells, which showed an immunophenotype identical to the neoplastic cells present in the dermis: positive staining with anti-cytokeratins, CEA, EMA, and GCDFP-15 and negative with anti-S-100 protein and HMB-45. These findings ruled out the possibility of a collision lesion, or simultaneous occurrence of melanoma and metastatic breast carcinoma. Pagetoid intraepidermal spread of metastatic breast carcinoma, as in our two cases, is exceptional. We also discuss the histogenetic similarities between our findings and those of mammary and extramammary Pagets disease, as well as the differential diagnosis of other cutaneous disorders characterized by pagetoid intraepidermal spread of neoplastic cells.


Journal of Cutaneous Pathology | 1992

Intravascular lymphomatosis: report of an unusual case with T cell phenotype occurring in an adolescent male

Omar Sangüeza; D. M. Hyder; Pastor Sangueza

Intravascular lymphomatosis is a rare disorder which most often occurs in the elderly. The overwhelming majority of the cases studied immiinophenotypically have expressed a B cell pheno‐typc. We report an unusual case of T cell intravascular lymphomatosis occurring in an adolescent male.


American Journal of Dermatopathology | 1993

DNA determination in dysplastic nevi: A comparative study between flow cytometry and image analysis

Omar Sangüeza; Dan M. Hyder; Antony C. Bakke; Clifton R. White

Dysplastic nevi (DN), described in 1978, have been associated with increased risk of melanoma, but the role of DN as precursors of melanoma is still controversial. Recent studies have shown that DN are very common in the general population, bringing into question this purported association. Numerous investigations have attempted to correlate the presence of DN in individuals with specific phenotypic and genotypic features, including the presence of abnormal DNA content. Because the occurrence of such abnormal DNA stemlines in neoplasms may be associated with malignant behavior, we studied 38 biopsies from 19 patients that histologically fulfilled criteria for DN in order to ascertain characteristics of DNA content. Nuclear suspensions made from paraffin-embedded tissue were evaluated by both flow cytometry and image analysis techniques. All cases demonstrated diploid populations by both DNA measurement methods. Our results contradict previous reports of aneuploid populations in these melanocytic lesions.


American Journal of Dermatopathology | 1990

Rhabdomyoma of the tongue

Omar Sangüeza; Pastor Sangüeza; Jose Jordan; Clifton R. White

Rhabdomyomas, which are rare striated muscle neoplasms, may occur on oral or genital mucosal surfaces as well as on the skin. Little discussion of rhabdomyomas occurs in any dermatology or dermatopathology literature. We report an 84-year-old patient who had a rhabdomyoma of her lateral tongue and discuss the clinical and histologic characteristics of this unusual type of benign neoplasm.


The Journal of Dermatologic Surgery and Oncology | 1994

Merkel Cell Carcinoma: Histopathology, Immunohistochemistry, and Cytogenetic Analysis

Whitney D. Tope; Omar Sangüeza


American Journal of Dermatopathology | 1995

Subtle clues to the diagnosis of the herpesvirus by light microscopy. Herpetic syringitis.

Omar Sangüeza; M. D. Gordon; C. R. White


Analytical and Quantitative Cytology and Histology | 1992

Comparison of image analysis with flow cytometry for DNA content analysis in pigmented lesions of the skin

Omar Sangüeza; Hyder Dm; White Cr; Pallander J; Perkins M; Remple N; Antony C. Bakke

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Luis Requena

Autonomous University of Madrid

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D. M. Hyder

Good Samaritan Hospital

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