Showing papers by "Geraldine S. Pinkus published in 1999"

Breakpoints of the t(11;18)(q21;q21) in Mucosa-associated Lymphoid Tissue (MALT) Lymphoma Lie within or near the Previously Undescribed Gene MALT1 in Chromosome 18

Abstract: Lymphomas arising in mucosa-associated lymphoid tissue (MALT) are indolent B-cell tumors that have a predilection for epithelial sites and often develop in a setting of chronic inflammation or autoimmunity. As many as 50% of low-grade MALT lymphomas contain an (11;18)(q21; q21) chromosomal translocation. Using fluorescence in situ hybridization, we have analyzed the position of recombination within chromosome 18 DNA in three examples of MALT lymphoma bearing this translocation. In all three cases, the breakpoint maps to DNA in BAC b357H2, covering about 150 kb of sequence. A previously undescribed, ubiquitously expressed gene, which we refer to as MALT1, was identified within this sequence and was found to be broken in one case for which we have definitively located the position of recombination between chromosomes 18 and 11. The sequence of this gene indicates the presence of two immunoglobulin-like C2 domains and a region of partial homology to caspases, suggesting a possible role for MALT1 in the regulation of apoptosis.

Nodular lymphoid lesion of the liver: an immune-mediated disorder mimicking low-grade malignant lymphoma.

Abstract: Three cases of unusual lymphoid infiltrate forming nodular macroscopic masses in the liver were studied in the authors' surgical pathology laboratory. These lesions posed difficulty in diagnosis, and their differentiation from low-grade lymphoma was not possible on histopathologic evaluation alone. The liver masses were analyzed histologically and immunohistochemically as well as for clonal immunoglobulin heavy chain (IgH) and T-cell receptor gamma (TCR-gamma) gene rearrangements. The lesions were seen as solitary grossly distinct firm nodules in all three patients, measuring 0.4, 0.7, and 1.5 cm, respectively, in their greatest dimensions. Two were found in livers removed because of end-stage primary biliary cirrhosis at the time of orthotopic liver transplantation, and the third was an incidental finding during laparotomy. Microscopically, these were nodules composed of small lymphocytes, plasma cells, and immunoblasts, with varying degrees of admixed acute inflammatory cells and scattered lymphoid follicles. By immunohistochemistry and molecular studies, these were found to be reactive lymphoid proliferations. All patients are alive and well at 2, 4, and 13 years, respectively. It is concluded that these cases represent a unique type of nodular lymphoid lesion, which is probably an immune-mediated benign reactive hyperplasia. It constitutes an entity by itself and must be distinguished from low-grade lymphoma. For a definitive diagnosis, immunohistochemistry and molecular studies are required.

MALT) Lymphoma Lie within or near the Previously Undescribed Gene MALT1 in Chromosome 18 1

Abstract: Lymphomas arising in mucosa-associated lymphoid tissue (MALT) are indolent B-cell tumors that have a predilection for epithelial sites and often develop in a setting of chronic inflammation or autoimmunity. As many as 50% of low-grade MALT lymphomas contain an (11;18)(q21; q21) chromosomal translocation. Using fluorescence in situ hybridization, we have analyzed the position of recombination within chromosome 18 DNA in three examples of MALT lymphoma bearing this translocation. In all three cases, the breakpoint maps to DNA in BAC b357H2, covering about 150 kb of sequence. A previously undescribed, ubiquitously expressed gene, which we refer to as MALT1, was identified within this sequence and was found to be broken in one case for which we have definitively located the position of recombination between chromosomes 18 and 11. The sequence of this gene indicates the presence of two immunoglobulin-like C2 domains and a region of partial homology to caspases, suggesting a possible role for MALT1 in the regulation of apoptosis.

Idiopathic pinealitis: Case report

Abstract: This 63-year-old man presented with complaints of "having a feeling of falling backward" over a 3-month period. Results of his general physical examination, laboratory studies, and neurological examination were unremarkable. A magnetic resonance image revealed a 1.8 x 1.4 x 1.2-cm enhancing mass in the posterior third ventricle just above the corpora quadrigemina. The pineal gland was found to be diffusely enlarged at operation and separable from the posterior thalamus and was totally resected. The patient had an uneventful postoperative course but continues to be somewhat confused. The lesion consisted of a remarkable chronic inflammatory cell infiltrate permeating the pineal lobules and was composed of T and B lymphocytes, macrophages, eosinophils, and mast cells. Immunoperoxidase studies did not demonstrate Langerhans cells, and a search for microorganisms was unrevealing. There was no evidence of neoplasia; results of immunostaining for germ cell markers and other tumor-associated antigens were negative.