Low-grade B-cell Lymphoma of Mucosa-associated Lymphoid Tissue in the Thymus of a Patient with Pulmonary Amyloid Nodules

Abstract

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-type lymphoma) is a rare thymic tumor, with only seven previous cases described worldwide to date. We describe the only case to have presented with pulmonary amyloid nodules. A 63-year-old Japanese female was found to have an anterior mediastinal tumor and multiple bilateral pulmonary nodules during a medical check-up in 1990 followed by chest radiography and computerized tomography. Because the mediastinal tumor grew larger, she was referred to the National Cancer Center Hospital East and hyperglobulinemia was pointed out. The thymus was resected through median sternotomy and pulmonary nodules were also resected through left thoracotomy. The solid and nodular tumor with several small satellite extensions and cyst formation was completely confined to within the thymus and the resected pulmonary nodules consisted of solid masses with a rough surface. Histologically, monotonous medium-sized centrocyte-like cells occupied the medulla of the thymus and infiltrated Hassall's corpuscles (lymphoepithelial lesions) and the resected pulmonary nodules consisted of eosinophilic amorphous deposits which showed birefringence on Congo Red staining. Immunohistochemically, the tumor cells were positive for CD20 and CD79a. IgG and kappa light chain restrictions were also found in plasmacytoid cells in the tumor. Clonal rearrangement of the immunoglobulin heavy chain gene was demonstrated by polymerase chain reaction. We diagnosed this case as low-grade B-cell MALT-type lymphoma in the thymus and nodular pulmonary amyloidosis. Since the patient had only localized amyloid deposits in the lung far from the thymic malignant lymphoma and had high serum immunoglobulins, the pulmonary amyloid deposits might be derived from a circulating precursor associated with hyperglobulinemia.

Primary Thymic Extranodal Marginal-Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue Type Exhibits Distinctive Clinicopathological and Molecular Features

“…[12][13][14][15][16][17][18][19][20][21][22][23] It is noteworthy that at least 17 (77%) of these patients are Asians. The apparent rarity of this lymphoma type in Caucasians suggests that there may be racial and/or environmental factors influencing its development.…”

“…Nine of these cases have previously been reported. 12,13,[15][16][17][21][22][23] All specimens were obtained at initial presentation and were reviewed by two independent pathologists (HI and SN). All tissue samples were fixed in 10% buffered formalin and embedded in paraffin.…”

“…2,3,10,11 Primary low-grade B-cell MALT lymphoma is very rare in the thymus, with only 16 cases having been reported in the literature to date. [12][13][14][15][16][17][18][19][20][21][22][23] Because the largest series has included only three cases, 20 and follow-up information is limited, the clinicopathological and behavioral features of this lymphoma type have not been clearly delineated.…”

Primary Extranodal Marginal Zone B-cell Lymphoma of Mucosa-Associated Lymphoid Tissue-type in the Thymus of a Patient with Sjögren's Syndrome and Rheumatoid Arthritis

“…Thymic MZBL of MALT-type is an extremely rare disease with only 22 cases having been reported in the literature to date, including one Korean case (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). According to Inagaki et al (19) who systematically investigated 15 cases of thymic MALT lymphoma, this tumor entity revealed prevalence in Asians, marked female predilection, strong association with autoimmune diseases, especially Sjogren' s syndrome, mostly IgA phenotype, and consistent lack of API2-MLT1 gene fusion, a recently reported MALT lymphoma-specific gene abnormality.…”

“…Primary MZBLs of MALT-type have been described in a variety of sites, including gastrointestinal tract (1), thyroid gland (4) , lung (5), salivary gland (6), and ocular adnexa (7) associated with clinical setting of autoimmune diseases or chronic inflammation, usually Sjogren' s syndrome, Hashimoto' s thyroiditis, and Helicobacter pylori infection. Thymic MZBL of MALT-type is an extremely rare disease with only 22 cases having been reported in the literature to date and the largest series has included 15 cases (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). In this paper, I report a case of low-grade MZBL of MALT-type in the thymus of a patient with Sjogren' s syndrome and rheumatoid arthritis.…”