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Lymphoscintigraphy
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Rimma Axelsson, Maria Holstensson, Ulrika Estenberg
The lymphatic system consists of lymphatic vessels, lymphatic nodes, and organized lymphoid tissue in different organs, such as tonsils, spleen, and bone marrow. Lymphatic vessels, lymphatic nodes, and lymphoid tissue are distributed throughout the whole body. The lymphatic system is more developed in organs that come into direct contact with the external environment, for example tonsils and skin.
The immune and lymphatic systems, infection and sepsis
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
Michelle Treacy, Caroline Smales, Helen Dutton
Lymphoid tissue is composed of reticular connective tissue, which provides support for lymphocytes and macrophages. These lymphocytes and macrophages can quickly squeeze through the capillary walls to circulate in the blood. This recirculation of lymphocytes between the blood, lymphatic tissues and organs is vitally important in exposing many lymphocytes to an invading pathogen or antigen. Depending on the route of entry the antigen, will be conveyed from the site of infection to the lymphatic tissues, where antigen-presenting cells, e.g., dendritic cells of lymphoid tissue and macrophages, are waiting to phagocytose the microbes and present the microbial antigen on their surface for antibodies to respond to. Antigens causing a tissue infection will be conveyed to the appropriate draining lymph nodes: the lymph node effectively closes down to retain the antigen-specific cells within the lymph node, thereby containing the infection within a small area (Stewart 2012). This causes swollen, painful lymph nodes, as experienced with an infection within the tonsils (tonsillitis). Cancerous cells can also be trapped within the lymph node: the node may become swollen but not painful, which is a useful sign in differentiating between infection and cancer.
Lymphoma
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Sarah J Vinnicombe, Rodney J Hicks
MALT lymphomas arise from epithelial and mucosal sites that normally have no organized lymphoid tissue, within which lymphoid tissue has arisen as a result of chronic inflammation or autoimmunity. Examples include Hashimoto's thyroiditis, Sjögren's syndrome and Helicobacter-induced chronic follicular gastritis. The association between gastric MALT lymphoma and H. pylori infection was established in 1991 by Wotherspoon et al. (137), who found the organism in over 90% of cases and demonstrated remission in response to antibiotic treatment for H. pylori. More recent studies suggest that the incidence of gastric MALT lymphoma is decreasing as a result of widespread eradication therapy for H. pylori. Consequently, fewer cases are associated with H. pylori at diagnosis (138).
How to recognize inborn errors of immunity in a child presenting with a malignancy: guidelines for the pediatric hemato-oncologist
Published in Pediatric Hematology and Oncology, 2023
Jutte van der Werff ten Bosch, Eva Hlaváčková, Charlotte Derpoorter, Ute Fischer, Francesco Saettini, Sujal Ghosh, Roula Farah, Delfien Bogaert, Rabea Wagener, Jan Loeffen, Chris M Bacon, Simon Bomken
Often the first to diagnose a specific malignancy, pathologists have an early opportunity to consider the possibility of an underlying IEI in a child with cancer. This is facilitated by the examination of surgical biopsies. Lymphomas presenting in children with IEI are often histologically identical to those occurring sporadically, even if the age and tissue distribution of specific lymphoma types differs.68 In contrast, some lymphoid neoplasms such as polymorphic lymphoproliferative disorders and EBV-associated mucocutaneous ulcers are highly associated with immunodeficiency, while the presence of certain morphological features in a common lymphoma type, such as polymorphic or Hodgkin-like features in a frank diffuse large B-cell lymphoma, may also suggest immunodeficiency.69–72 These lesions are typically EBV-positive, as are some immunodeficiency-associated marginal zone lymphomas and T/NK-cell lymphomas, and all pediatric lymphomas should be tested for EBV-association by in situ hybridization with positive findings correlated with peripheral blood EBV levels and serology.73,74 However, EBV-positivity alone is not sufficient to indicate an underlying IEI. Any non-neoplastic lymphoid tissue sampled should be carefully examined for the abnormal constituent cell populations or altered lymphoid architecture described in several IEIs.75–78
Activation of Conjunctiva-Associated Lymphoid Tissue in Diabetic Patients
Published in Ocular Immunology and Inflammation, 2023
Yuting Liu, Jingrao Wang, Xin Jin, Yingbin Wang, Yan Shi, Nan Zhang, Rui Zhu, Yueyan Dong, Hong Zhang
We observed diffuse lymphoid tissue and lymphoid follicles and selected 3 pictures of each part of the conjunctiva for further analysis. The diffuse lymphoid tissue is composed of lymphocytes in the epithelial layer and lamina propria. The cells in this layer mainly include T lymphocytes and plasma cells. The confocal microscopy images showed a layered structure composed of highly reflective, irregularly shaped cells. Follicles are oval-shaped structures located under the epithelial layer. Highly reflective parafollicular lymphocytes could be observed around the germinal center. Three images were selected for analysis of diffuse lymphoid tissue for each eye, and three images were analyzed for follicular-related parameters. A total of 768 IVCM images were analyzed for both eyes, and 192 IVCM images were analyzed for one eye in each group.
Drug delivery to the intestinal lymph by oral formulations
Published in Pharmaceutical Development and Technology, 2022
Takayuki Yoshida, Hiroyuki Kojima, Kazuhiro Sako, Hiromu Kondo
Approximately 95% of lymphocytes are located in the lymph and lymphoid tissues, and 50%–70% of the lymphocytes in the body are present in gut-associated lymphoid tissue (GALT) and the intestinal lymphatic system (Guy-Grand and Vassalli 1993; Cesta 2006). T-cells are present in the lymph (98.6%) and blood (1.4%) (Fischer et al. 1996; Kaplan and Mcpherson 2007; Fanous et al. 2007). The concentration of helper T-cells in the mesenteric lymphatic fluid is 2.1 × 105 cells/µL (Fischer et al. 1996; Fanous et al. 2007), which is 76-fold higher than that in the blood (1.1 × 103 cells/µL) (Kaplan and Mcpherson 2007). Orally administered DDS used to target the intestinal lymph achieve efficient exposure of lymphocytes to drugs (Guy-Grand and Vassalli 1993; Fischer et al. 1996; Cesta 2006; Kaplan and Mcpherson 2007; Fanous et al. 2007; Trevaskis et al. 2010a; Yoshida et al. 2016; Yoshida et al. 2020).