T-Cell/Histiocyte-Rich Large B-Cell Lymphoma of the Thyroid
© Ichikawa et al.; licensee BioMed Central Ltd. 2013
Received: 25 November 2012
Accepted: 5 January 2013
Published: 9 January 2013
T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare subtype of diffuse large B-cell lymphoma, and has been reported to mainly affect lymph nodes with advanced Ann Arbor stage. We present a 69-year-old woman with a past history of chronic thyroiditis, who had suffered from rapidly-growing thyroid tumor. No other lymph nodes swelling or extranodal lesions were detected. She promptly underwent surgery with resection of the thyroid tumor, and the diagnosis of THRLBCL was established pathologically. She was successfully treated by standard rituximab-containing chemotherapy. To our knowledge, this is the first case report of THRLBCL exclusively arising in the thyroid.
KeywordsT-cell/histiocyte-rich large B-cell lymphoma Thyroid lymphoma R-CHOP
To the editor
THRLBCL is a rare morphological subtype of diffuse large B-cell lymphoma (DLBCL), which is characterized by a limited number of scattered, large, atypical B-cells embedded in a background of abundant T-cells and frequently histiocytes . THRLBCL has been reported to mainly affect lymph nodes, and most cases are at advanced Ann Arbor stage with intermediate to high risk of IPI [1–3]. Although extranodal involvement of THRLBCL is not uncommon, an exclusively extranodal presentation at diagnosis is extremely rare; Weshi et al  reported that all of 61 cases investigated had lymph node lesions. In contrast to these observations, our case had a single thyroid tumor with an IPI score indicating low-intermediate risk. To our knowledge, this is the first case report of THRLBCL exclusively arising in the thyroid.
Malignant lymphoma is a minor component of thyroid tumors, accounting for only 2 to 5% of all thyroid malignancies. Thyroid lymphoma is often associated with chronic thyroiditis, and mostly diagnosed as DLBCL and MALT lymphoma pathologically . Also in this case, the past history of chronic thyroiditis might be associated with the emergence of lymphoma.
THRLBCL is considered an aggressive lymphoma. It has also been reported that THRLBCL with histiocytes could represent a very aggressive lymphoma . Although the biological characteristics seem to be different from DLBCL and the effects of rituximab for THRLBCL remain to be determined, it is recommended at present that THRLBCL should be treated similar to stage-matched DLBCL . On the other hand, localized extranodal DLBCL is often treated with radiation therapy with or without chemotherapy, as reported in gastric lymphoma . In this case, however, a tracheotomy was done before lymphoma treatment and radiation therapy could cause airway trouble; so that the patient was treated with R-CHOP chemotherapy without radiation. The patient described here showed a good clinical course; however, careful observation is indispensable to monitor disease relapse at both the primary site and distant sites.
This article is published under license to BioMed Central Ltd. licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.