No abstract available.
Animals ; Erythrocytes* ; Germinal Center* ; Mice* ; Sheep* ; Spleen*

No abstract available.
Animals ; Germinal Center* ; Lymph Nodes* ; Mice*

OBJECTIVETo improve the understanding of progressive transformation of lymph node germinal centers (PTGC) and to explore its clinical, histopathologic and immunohistochemical features and the differential diagnosis between the related disease of germinal center hyperplasia.

METHODSThe clinical manifestation, laboratory bindings, treatment and outcome of a patient with PTGC were presented.

RESULTSThe main manifestation of the patient was painless peripheral lymphadenopathy. Histopathologic examination of an axillary lymph node showed reactive follicular hyperplasia and the progressive transformation changes germinal centers. The borderline between the germinal center and the mantle layer was obscured. The cells in the progressive transforming germinal centers were positive for CD20(+), CD5(+), CDw75(+).

CONCLUSIONPTGC is a rare lymphoid disorder. Histopathology and immunohistochemistry are important basis of the diagnosis.

Understanding germinal center reactions is crucial not only for the design of effective vaccines against infectious agents and malignant cells but also for the development of therapeutic intervention for the treatment of antibody-mediated immune disorders. Recent advances in this field have revealed specialized subsets of T cells necessary for the control of B cell responses in the follicle. These cells include follicular regulatory T cells and Qa-1-restricted cluster of differentiation (CD)8+ regulatory T cells. In this review, we discuss the current knowledge related to the role of regulatory T cells in the B cell follicle.
Germinal Center ; Immune System Diseases ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer ; T-Lymphocytes, Regulatory* ; Vaccines

Progressive transformation of germinal centers (PTGC) is an atypical feature seen in lymph nodes with unknown pathogenesis. PTGC most commonly presents in adolescent and young adult males as solitary painless lymphadenopathy with various durations. Cervical nodes are the most commonly involved ones while involvements of axillary and inguinal nodes are less frequent. PTGC develops extremely rarely in other locations. We report a rare case of solitary mass present in the presacral space. The mass as subsequently proven to be PTGC. To the best of our knowledge, PTGC in the presacral space has not been previously reported in the literature.
Adolescent ; Germinal Center* ; Humans ; Lymph Nodes ; Lymphatic Diseases ; Magnetic Resonance Imaging* ; Male ; Young Adult

Kimura's disease is a rare chronic inflammatory disorder with slowly enlarging subcutaneous masses. We report a case of Kimura's disease in a 33-year-old man who had such disease since childhood. He had asymptomatic variable sized, skin colored subcutaneous masses on the left cheek, both mastoid area, right epicanthus, and right parotid area. A biopsy specimen showed many lymphoid follicles with germinal center in dermis and a dense infiltration composed of small lymphocytes, plasma cells, histiocytes, and eosinophils. He was treated with triamcinolone intra-lesional injections(10 mg/ml).
Adult ; Biopsy ; Cheek ; Dermis ; Eosinophils ; Germinal Center ; Histiocytes ; Humans ; Lymphocytes ; Mastoid ; Plasma Cells ; Skin ; Triamcinolone

Lymphoid polyp is a very rare disease that commonly occurs in the rectum. It is a benign, focal or diffuse lesion that typically occurs where clusters of lymphoid follicles are present. The polyp is composed of well differentiated lymphoid tissue. It can generally be differentiated from malignant lymphoma by the proliferation of normal lymphoid tissue, which has a prominent follicular pattern and a clearly defined germinal center. There have been only a few reports of lymphoid polyps of the rectum, and there have been no reports of lymphoid polyp in the ampulla of Vater. We experienced a case of lymphoid polyp in the ampulla of Vater associated with tubulopapillary adenoma, and the patient first presented with jaundice, weight loss and general weakness.
Adenoma ; Ampulla of Vater ; Germinal Center ; Humans ; Jaundice ; Lymphoid Tissue ; Lymphoma ; Polyps ; Rare Diseases ; Rectum ; Weight Loss

Recent advances in the understanding of the biology of Hodgkin lymphoma have led to a new classification. Hodgkin lymphoma is now recognized as a B-cell disorder of germinal center or post-germinal center origin. In the WHO classification, Hodgkin lymphoma consists of two categories, namely, nodular lymphocyte predominant Hodgkin lymphoma and classical Hodgkin lymphoma. Classical Hodgkin lymphoma encompasses not only nodular sclerosis, mixed cellularity, and lymphocyte depletion subtypes, but also lymphocyte-rich subtype, among which, nodular sclerosis stands out as a distinct entity. A borderline neoplasm with features intermediate between Hodgkin lymphoma and diffuse large B-cell lymphoma has also been recognized.
B-Lymphocytes ; Biology ; Diagnosis, Differential ; Germinal Center ; Hodgkin Disease ; Lymphocyte Depletion ; Lymphocytes ; Lymphoma, B-Cell ; Sclerosis

BACKGROUND: Follicular lymphomas present with various immunohistologic patterns. The immunohistochemical markers used in the diagnosis of follicular lymphoma show variable degrees of sensitivity and specificity, and thus, additional germinal center markers are required. Smad1 has been reported to be overexpressed in follicular lymphoma, but little is known regarding the expression patterns of Smad proteins in human lymphoid tissue. METHODS: In the present study, we performed immunohistochemistry for traditional germinal center markers and for Smad1 in human reactive lymphoid and follicular lymphoma tissues to investigate Smad1's usefulness in the diagnosis of follicular lymphoma. RESULTS: In the reactive germinal centers, most cells were positive for Smad1. Among the 27 follicular lymphoma cases, 17 of 21 (80%) were Smad1 positive, 17 of 27 (63%) were positive for CD10, and 23 of 27 (85%) were positive for Bcl6. Notably, three cases expressed CD10 only, and one only expressed Bcl6. All these cases were grade 3 tumors and showed follicular and diffuse growth patterns. CONCLUSIONS: These results indicate that Smad1 is a candidate as a germinal center marker. Furthermore, they suggest that the Smad signaling pathway might be involved in follicular lymphoma.
Diagnosis ; Germinal Center ; Humans ; Immunohistochemistry ; Lymphoid Tissue ; Lymphoma ; Lymphoma, Follicular* ; Sensitivity and Specificity ; Smad Proteins

Kimura's disease is a rare benign disease characterized by subcutaneous or dermal tumors occurring predominantly on the head and the neck. It usually occurs in young adults without constitutional symptoms, except for peripheral blood eosinophilia. The histopathologic features of the tumor are characterized by dense lymphoid aggregates containing a prominent germinal center and by the proliferation of endothelial cells associated with varying degrees of lymphocytic, histiocytic, and eosinophilic infiltration. We report a case of Kimura's disease without peripheral blood eosinophilia in a 24-year-old male who had had a painless and slowly growing tumor-like swelling on his right groin for one year. The mass was excised, and the specimen was confirmed as Kimura's disease. After surgical excision, the lesion recurred, so 30 mg of oral prednisone was given daily for one month and then decreased gradually for another one month. Now, the lesion is completely healed.
Endothelial Cells ; Eosinophilia ; Eosinophils ; Germinal Center ; Groin* ; Head ; Humans ; Male ; Neck ; Prednisone ; Young Adult