| Progressive transformation of germinal centres | |
|---|---|
| Other names | progressive transformation of germinal centers |
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| Micrograph of a lymph node biopsy showing progressive transformation of germinal centres. H&E stain. | |
| Specialty | Infectious disease |
Progressive transformation of germinal centres (PTGCs) is a reactive lymph node process of undetermined cause.
PTGC is usually characterized by localized lymphadenopathy and is otherwise typically asymptomatic.
PTGC is diagnosed by surgical excision of the affected lymph node(s), and examination by a pathologist. The differential diagnosis includes non-neoplastic causes of lymphadenopathy (e.g. cat-scratch fever, Kikuchi disease) and malignancy, i.e. cancer.
PTGCs is characterized by: [1]
PTGC is treated by excisional biopsy and follow-up. It may occasionally recur and a small proportion of patients have been reported to subsequently develop nodular lymphocyte predominant Hodgkin lymphoma. [2] [3]
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes. The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph nodes, fever, drenching sweats, unintended weight loss, itching, and constantly feeling tired. The enlarged lymph nodes are usually painless. The sweats are most common at night.
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphoid tissues and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation..
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function.
Reed–Sternberg cells are distinctive, giant cells found with light microscopy in biopsies from individuals with Hodgkin lymphoma. They are usually derived from B lymphocytes, classically considered crippled germinal center B cells. In the vast majority of cases, the immunoglobulin genes of Reed–Sternberg cells have undergone both V(D)J recombination and somatic hypermutation, establishing an origin from a germinal center or postgerminal center B cell. Despite having the genetic signature of a B cell, the Reed–Sternberg cells of classical Hodgkin lymphoma fail to express most B-cell–specific genes, including the immunoglobulin genes. The cause of this wholesale reprogramming of gene expression has yet to be fully explained. It presumably is the result of widespread epigenetic changes of uncertain etiology, but is partly a consequence of so-called "crippling" mutations acquired during somatic hypermutation. Seen against a sea of B cells, they give the tissue a moth-eaten appearance.
Castlemandisease (CD) describes a group of rare lymphoproliferative disorders that involve enlarged lymph nodes, and a broad range of inflammatory symptoms and laboratory abnormalities. Whether Castleman disease should be considered an autoimmune disease, cancer, or infectious disease is currently unknown.
Tumors of the hematopoietic and lymphoid tissues or tumours of the haematopoietic and lymphoid tissues are tumors that affect the blood, bone marrow, lymph, and lymphatic system. Because these tissues are all intimately connected through both the circulatory system and the immune system, a disease affecting one will often affect the others as well, making aplasia, myeloproliferation and lymphoproliferation closely related and often overlapping problems. While uncommon in solid tumors, chromosomal translocations are a common cause of these diseases. This commonly leads to a different approach in diagnosis and treatment of hematological malignancies. Hematological malignancies are malignant neoplasms ("cancer"), and they are generally treated by specialists in hematology and/or oncology. In some centers "hematology/oncology" is a single subspecialty of internal medicine while in others they are considered separate divisions. Not all hematological disorders are malignant ("cancerous"); these other blood conditions may also be managed by a hematologist.
Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type is lymphadenitis, producing swollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated as synonymous. Inflammation of the lymphatic vessels is known as lymphangitis. Infectious lymphadenitis affecting lymph nodes in the neck is often called scrofula.
Follicular lymphoma (FL) is a cancer that involves certain types of white blood cells known as lymphocytes. The cancer originates from the uncontrolled division of specific types of B-cells known as centrocytes and centroblasts. These cells normally occupy the follicles (nodular swirls of various types of lymphocytes) in the germinal centers of lymphoid tissues such as lymph nodes. The cancerous cells in FL typically form follicular or follicle-like structures (see adjacent Figure) in the tissues they invade. These structures are usually the dominant histological feature of this cancer.
The B-cell lymphomas are types of lymphoma affecting B cells. Lymphomas are "blood cancers" in the lymph nodes. They develop more frequently in older adults and in immunocompromised individuals.
Splenic marginal zone lymphoma (SMZL) is a type of cancer made up of B-cells that replace the normal architecture of the white pulp of the spleen. The neoplastic cells are both small lymphocytes and larger, transformed lymphoblasts, and they invade the mantle zone of splenic follicles and erode the marginal zone, ultimately invading the red pulp of the spleen. Frequently, the bone marrow and splenic hilar lymph nodes are involved along with the peripheral blood. The neoplastic cells circulating in the peripheral blood are termed villous lymphocytes due to their characteristic appearance.
Angioimmunoblastic T-cell lymphoma is a mature T-cell lymphoma of blood or lymph vessel immunoblasts characterized by a polymorphous lymph node infiltrate showing a marked increase in follicular dendritic cells (FDCs) and high endothelial venules (HEVs) and systemic involvement.
Mantle cell lymphoma (MCL) is a type of non-Hodgkin's lymphoma, comprising about 6% of cases. It is named for the mantle zone of the lymph nodes where it develops. The term 'mantle cell lymphoma' was first adopted by Raffeld and Jaffe in 1991.
Rosai–Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy or sometimes as Destombes–Rosai–Dorfman disease, is a rare disorder of unknown cause that is characterized by abundant histiocytes in the lymph nodes or other locations throughout the body.
Marginal zone B-cell lymphomas, also known as marginal zone lymphomas (MZLs), are a heterogeneous group of lymphomas that derive from the malignant transformation of marginal zone B-cells. Marginal zone B cells are innate lymphoid cells that normally function by rapidly mounting IgM antibody immune responses to antigens such as those presented by infectious agents and damaged tissues. They are lymphocytes of the B-cell line that originate and mature in secondary lymphoid follicles and then move to the marginal zones of mucosa-associated lymphoid tissue, the spleen, or lymph nodes. Mucosa-associated lymphoid tissue is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body such as the gastrointestinal tract, mouth, nasal cavity, pharynx, thyroid gland, breast, lung, salivary glands, eye, skin and the human spleen.
Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a slow-growing CD20 positive form of Hodgkin lymphoma, a cancer of the immune system's B cells.
Hodgkin lymphoma (HL) is a type of lymphoma in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells are present in the patient's lymph nodes. The condition was named after the English physician Thomas Hodgkin, who first described it in 1832. Symptoms may include fever, night sweats, and weight loss. Often, nonpainful enlarged lymph nodes occur in the neck, under the arm, or in the groin. Those affected may feel tired or be itchy.
Follicular hyperplasia (FH) is a type of lymphoid hyperplasia and is classified as a lymphadenopathy, which means a disease of the lymph nodes. It is caused by a stimulation of the B cell compartment and by abnormal cell growth of secondary follicles. This typically occurs in the cortex without disrupting the lymph node capsule. The follicles are pathologically polymorphous, are often contrasting and varying in size and shape. Follicular hyperplasia is distinguished from follicular lymphoma in its polyclonality and lack of bcl-2 protein expression, whereas follicular lymphoma is monoclonal, and expresses bcl-2.
In situ lymphoid neoplasia is a precancerous condition newly classified by the World Health Organization in 2016. The Organization recognized two subtypes of ISLN: in situ follicular neoplasia (ISFN) and in situ mantle cell neoplasia (ISMCL). ISFN and ISMCL are pathological accumulations of lymphocytes in the germinal centers and mantle zones, respectively, of the follicles that populate lymphoid organs such as lymph nodes. These lymphocytes are monoclonal B-cells that may develop into follicular (FL) and mantle cell (MCL) lymphomas, respectively.
T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a malignancy of B cells. B-cells are lymphocytes that normally function in the humoral immunity component of the adaptive immune system by secreting antibodies that, for example, bind to and neutralize invasive pathogens. Among the various forms of B-cell lymphomas, THRLBCL is a rarely occurring subtype of the diffuse large B-cell lymphomas (DLBCL). DLBCL are a large group of lymphomas that account for ~25% of all non-Hodgkin lymphomas worldwide. THRLBCL is distinguished from the other DLBCL subtypes by the predominance of non-malignant T-cell lymphocytes and histiocytes over malignant B-cells in its tumors and tissue infiltrates.
Indolent lymphoma, also known as low-grade lymphoma, is a group of slow-growing non-Hodgkin lymphomas (NHLs). Because they spread slowly, they tend to have fewer signs and symptoms when first diagnosed and may not require immediate treatment. Symptoms can include swollen but painless lymph nodes, unexplained fever, and unintended weight loss.