The vitamin D receptor gene polymorphism and parathyroid function.
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Biomedical subjects
Publications and source records attributed to E Cristóbal.
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A 48-year-old HIV-seropositive homosexual patient presented with an ulcerative lesion in the left side of the soft palate, extensively involving local soft tissue structures. On histologic evaluation the lesions appeared to be a large-cell high-grade B-cell pleomorphic lymphoma with anaplastic and plasmacytoid features harboring Epstein-Barr virus genome in the tumor cells. Although known to be associated with HIV infection, this is a rare subtype of a malignant lymphoma arising in a patient positive for HIV. Its meaning is yet unknown in biologic and prognostic terms.
Undifferentiated nasopharyngeal carcinomas are universally associated with Epstein-Barr virus (EBV). This association has been exclusively established in lymphoepithelioma-like carcinomas in some locations. The relationship between EBV and lymphoepithelioma-like carcinomas in the larynx is unknown. In none of the few laryngeal lymphoepithelioma-like carcinomas reported have EBV investigations been carried out. We present here two supraglottic laryngeal lymphoepithelioma-like carcinomas in which EBV antigens were not demonstrable using immunohistochemical and molecular methods. Our results suggest that EBV may not be involved in laryngeal lymphoepithelioma-like carcinoma at least in Western patients.
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The recognition and classification of the different varieties of splenic low-grade B-cell lymphomas have been hampered by the rarity of histological studies of surgical splenectomy specimens of B-cell lymphoma. In an effort to characterize the recently described splenic marginal zone lymphoma (SMZL), we conducted a survey of 13 patients with this type of tumor using the criteria defined by Schmid for its recognition (Schmid et al., Am J Surg Pathol 1992;16:455-66). Primary splenic high-grade lymphomas, T-cell lymphomas, and secondary infiltration by other recognized low-grade B-cell lymphomas, with the exception of splenic lymphoma with villous lymphocytes, were excluded. This selection gave rise to a homogeneous group of tumors with similar clinical, histological, immunohistochemical, and molecular features. Our study showed the critical parameters for their recognition to be morphological, including macroscopic micronodularity and the constant presence of white- and red-pulp infiltration, marginal zone pattern, and plasmacytic differentiation. No t(14;18) or PRAD-1/cyclin D1 overexpression was detect able in any case. Clinically, the tumors were widespread with a protracted evolution. Nodal infiltration by SMZL in our cases was morphologically similar to monocytoid B-cell lymphoma. SMZL could constitute the largest group of primary splenic malignant lymphomas, partially overlapping with splenic lymphoma with villous lymphocytes. Specific molecular markers for SMZL have yet to be defined. Because of the limited number of cases, the question of therapy for this group of lymphomas must remain open for the future.
Neoplastic monocytoid B-cells (MBCs) are present in different amounts in several types of non-Hodgkin's lymphomas (NHLs), including monocytoid B-cell lymphoma (MBCL), splenic marginal zone lymphoma (SMZL), mucosa-associated lymphoid tissue (MALT) low-grade B-cell lymphomas, and follicular centroblastic-centrocytic (CB-CC) lymphomas. In an attempt to clarify the relationships between different groups of tumors with a significant monocytoid component, we studied six primary lymph node MBCL, three SMZL, seven MALT lymphomas, and four CB-CC with monocytoid differentiation. Their clinical, morphological, immunohistochemical and molecular features were compared. The results show wide overlapping between MALT and MBCL in terms of morphology, immunophenotype, and molecular features. Follicular colonization was a characteristic finding in both groups. Some MBCL revealed mucosal involvement during the course of the disease, suggesting a possible MALT origin. Our data support the suggestion that the use of the term MBCL should be discontinued in cases with mucosal involvement, as they are probably examples of lymph node involvement brought about by MALT lymphomas. Although SMZL have some overlapping features with MBCL and MALT lymphomas, some of the clinical and morphological specific findings justify their distinction from the other groups. The CB-CCs with monocytoid differentiation frequently harbored t(14;18), lacking any significant differentiating features from conventional follicular CB-CC lymphomas. Additional studies are needed to define the molecular features of MBCL and other marginal zone tumors.