Thymic Hyperplasia with Lymphoepithelial Sialadenitis (LESA)-Like Features: Strong Association with Lymphomas and Non-Myasthenic Autoimmune Diseases

Abstract

Thymic hyperplasia (TH) with lymphoepithelial sialadenitis (LESA)-like features (LESA-like TH) has been described as a tumor-like, benign proliferation of thymic epithelial cells and lymphoid follicles. We aimed to determine the frequency of lymphoma and autoimmunity in LESA-like TH and performed retrospective analysis of cases with LESA-like TH and/or thymic MALT-lymphoma. Among 36 patients (21 males) with LESA-like TH (age 52 years, 32–80; lesion diameter 7.0 cm, 1–14.5; median, range), five (14%) showed associated lymphomas, including four (11%) thymic MALT lymphomas and one (3%) diffuse large B-cell lymphoma. One additional case showed a clonal B-cell-receptor rearrangement without evidence of lymphoma. Twelve (33%) patients (7 women) suffered from partially overlapping autoimmune diseases: systemic lupus erythematosus (n = 4, 11%), rheumatoid arthritis (n = 3, 8%), myasthenia gravis (n = 2, 6%), asthma (n = 2, 6%), scleroderma, Sjögren syndrome, pure red cell aplasia, Grave’s disease and anti-IgLON5 syndrome (each n = 1, 3%). Among 11 primary thymic MALT lymphomas, remnants of LESA-like TH were found in two cases (18%). In summary, LESA-like TH shows a striking association with autoimmunity and predisposes to lymphomas. Thus, a hematologic and rheumatologic workup should become standard in patients diagnosed with LESA-like TH. Radiologists and clinicians should be aware of LESA-like TH as a differential diagnosis for mediastinal mass lesions in patients with autoimmune diseases.

GTF2I Mutation in Thymomas: Independence From Racial-Ethnic Backgrounds. An Indian/German Comparative Study

“…The German cohort included 15 (19,5%) type A thymomas, 31 (40,3%) type AB, 15 atypical A/AB (19,5%) and 16 (20,8%) type B1-B3 thymomas. The remaining 24 German cases comprised 18 thymic carcinomas, 2 cases of sclerosing mediastinitis, 2 metaplastic thymomas, 1 thymolipoma and 1 thymic hyperplasia with lymphoepithelial sialadenitis (LESA)-like features ( 10 ).…”

Thymic Hyperplasia With Lymphoepithelial Sialadenitis-Like Features Arising in a Patient With Immunoglobulin G4-Related Disorders: A Case Report

“…Thymic hyperplasia with lymphoepithelial sialadenitis-like features was assumed to be unrelated to autoimmune diseases; however, Porubsky et al reported a series of 36 cases in which they described that thymic hyperplasia with lymphoepithelial sialadenitis-like features was strongly associated with lymphomas and non-myasthenic autoimmune diseases. 5 In their case series, 5 cases had an accompanying B-cell lymphoma (4 MALT lymphomas and 1 diffuse large B-cell lymphoma). In comparison, 12 cases had an accompanying autoimmune disorder (4 systemic lupus erythematosus, 3 rheumatoid arthritis, 2 myasthenia gravis, 2 asthma, Sjogren's syndrome, scleroderma, pure red cell aphasia, Grave's disease, and anti-IgLON5 syndrome).…”

Benign lesions of the mediastinum

“…The lesion is characterized by expansion of epithelial cell meshworks with prominent lymphoepithelial lesions, numerous Hassall corpuscles undergoing cystic changes, a substantial or even complete cortical atrophy, and lymphofollicular hyperplasia, potentially resulting in an organ appearance reminiscent of a lymph node (Figure 2). The largest cohort published so far showed a slight male predominance and a mean age of 52 years (range 32–80 years) 17 . Moreover, it revealed that 14% of the patients had an associated lymphoma, in most cases a thymic MALT lymphoma, and 33% of the patients suffered from nonmyasthenic autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjögren syndrome, pure red cell aplasia, or Graves' disease (Figures 3 and 4).…”

“…The largest cohort published so far showed a slight male predominance and a mean age of 52 years (range 32-80 years). 17 Moreover, it revealed that 14% of the patients had an associated lymphoma, in most cases a thymic MALT lymphoma, and 33% of the patients suffered from nonmyasthenic autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sj€ ogren syndrome, pure red cell aplasia, or Graves' disease (Figures 3 and 4). These findings indicate that LESA-like TH is not merely an aggravated form of a TFH, but rather an entity of its own standing and that a haematologic and rheumatologic work-up should be warranted in patients diagnosed with LESA-like TH.…”

“…LESA-like TH is a tumorous proliferation of thymic epithelial cells and lymphoid follicles. 17,18 The lesion is characterized by expansion of epithelial cell meshworks with prominent lymphoepithelial lesions, numerous Hassall corpuscles undergoing cystic changes, a substantial or even complete cortical atrophy, and lymphofollicular hyperplasia, potentially resulting in an organ appearance reminiscent of a lymph node (Figure 2). The largest cohort published so far showed a slight male predominance and a mean age of 52 years (range 32-80 years).…”