Malignant lymphoma of mucosa-associated lymphoid tissue arising in the thymus of a patient with Sjögren's syndrome. A morphologic, phenotypic, and genotypic study.
A 59-year-old woman with Sjögren's syndrome had an anterior mediastinal tumor. The tumor had epithelium-lined thymic cysts. Histologically, centrocyte-like (CCL) cells were present as clusters intermingling with small lymphocytes and plasma cells, invaded the epithelium, and formed characteristic lymphoepithelial lesions; the tumor was identified as malignant lymphoma arising in mucosa-associated lymphoid tissue (MALT). Within the tumor, trapped Hassall's corpuscles were recognized. Immunohistochemical staining demonstrated monotypic cytoplasmic kappa light chains in a small portion of the CCL cells. Furthermore, Southern blot hybridization studies showed rearrangements of immunoglobulin heavy chain, immunoglobulin kappa light chain, and T-cell receptor beta genes. The findings are consistent with thymic low-grade B-cell MALT lymphoma.
Takagi
N
N
Department of Pathology, Aichi Cancer Center Hospital, Nagoya, Japan.
Nakamura
S
S
Yamamoto
K
K
Kunishima
K
K
Takagi
I
I
Suyama
M
M
Shinoda
M
M
Sugiura
T
T
Oyama
A
A
Suzuki
H
H
D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics; D005838:Genotype; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007147:Immunoglobulin Light Chains / Q000032:analysis; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D008221:Lymphoid Tissue / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000473:pathology*; D008854:Microscopy, Electron; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D015388:Organelles / Q000648:ultrastructure; D010641:Phenotype; D012859:Sjogren's Syndrome / Q000235:genetics / Q000473:pathology*; D013953:Thymus Neoplasms / Q000235:genetics* / Q000473:pathology*
D007070:Immunoglobulin A; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains