A multiparametric study of malignant lymphoma of mucosa associated lymphoid tissue (MALT).
A morphological, immunophenotypic and ultrastructural study, cell cycle estimation, DNA and cytogenetic analysis were performed in ten cases of B-MALT lymphomas. Five had low grade lymphoma and five had high grade. Low and high grade cases showed the same cells but in different percentages: These included centrocyte-like cells with occasional monocytoid cytoplasmic changes, and centroblast-like cells. However, in high grade cases more dysplastic and large cells were present. All cellular types showed an important development of rough endoplasmic reticulum. In all cases a large panel of monoclonal antibodies was employed to study the B-cell immunophenotype. Ki-67 positivity ranged from 5% to 30% in low-grade cases and from 50% to 70% in high-grade cases. Gene rearrangement analysis showed rearrangement with Jh probe and half of the cases were also rearranged with the Kde probe (Kappa constant chain gene). A rearrangement banding pattern with TCR genes was not present in any of the cases. Cytogenetic study showed complex alterations in high grade cases and a normal karyotype in low grade lymphomas. Only one case had rearrangement for the bcl-2 probe.
Rivas
C
C
Department of Pathology, Immunology and Genetics, Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain.
Echezarreta
G
G
García
R
R
Santos
M
M
Santon
A
A
Robledo
M
M
Benitez
J
J
Oliva
H
H
Delsol
G
G
D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005770:Gastrointestinal Neoplasms / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D015321:Gene Rearrangement; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008221:Lymphoid Tissue / Q000473:pathology; D008223:Lymphoma / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure