Terminal deoxynucleotidyl transferase-positive cells in human tonsils

• Published in: American journal of clinical pathology Vol. 116; no. 1; pp. 12 - 16
• Main Authors: STRAUCHEN, James A, MILLER, Lorraine K
• Format: Journal Article
• Language: English
• Published: Chicago, IL American Society of Clinical Pathologists 01.07.2001
• Subjects: Adolescent; Adult; Biological and medical sciences; Child; Child, Preschool; DNA Nucleotidyltransferases - metabolism; Hematologic and hematopoietic diseases; Humans; Hyperplasia; Immunohistochemistry; Infant; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Lymph Nodes - enzymology; Lymph Nodes - pathology; Medical sciences; Middle Aged; Palatine Tonsil - enzymology; Palatine Tonsil - pathology; Human; Immunohistochemistry; Amygdala; Enzyme; Transferases; Acute; Precursor cell; Histiogenesis; Lymphoblastic lymphoma; CFU-BL-Cell; Malignant hemopathy; B-Lymphocyte; Lymphoid tissue; Non Hodgkin lymphoma; DNA nucleotidylexotransferase; Pathology; Nucleotidyltransferases; Lymphoproliferative syndrome; Acute lymphocytic leukemia
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1309/M8V2-DWPB-DVX1-UBPC

To study the possible cellular origin of recently recognized indolent terminal deoxynucleotidyl transferase (TdT)-positive T-lymphoblastic proliferations of the tonsils and oropharynx, we studied normal human tonsils for the presence of TdT-positive cells. TdT-positive cells were readily demonstrated in the tonsils from 15 children and adults by immunohistochemical staining. TdT-positive cells were distributed in discrete foci at the periphery of lobules of lymphoid tissue and adjacent to fibrous septa and had the morphologic features of small to medium-sized lymphocytes. Double-antibody staining indicated the TdT-positive cells had the phenotype of uncommitted early lymphoid precursors (CD3-, CD79a-, CD10-). Foci of TdT-positive cells were not identified in 6 reactive lymph nodes studied as controls. These studies indicate that tonsils, like bone marrow and thymus, are sites of lymphopoiesis. The presence of TdT-positive precursor cells in human tonsils may be a factor in the pathogenesis of recently described indolent T-lymphoblastic proliferations involving the tonsils and oropharynx. The presence of TdT-positive cells in human tonsils should not be misinterpreted as evidence of lymphoblastic lymphoma or leukemia.