Metastatic Melanoma Definition Lymph node metastases of melanoma. Epidemiology The incidence of melanoma is increasing rapidly among Caucasians in America, Europe, and Australia. In the US, melanoma is increasing at…

Tumor Metastases in Lymph Nodes Partmark Metastatic Tumors in Lymph Nodes The involvement of lymph nodes by metastatic tumors signifies the start of a new phase in the progreWss of…

Lymphadenitis of Whipple Disease Definition Specific form of vascular neoplasm that occurs sporadically in the general population and frequently in persons with acquired immune deficiency. Epidemiology Kaposi sarcoma (KS) occurs…

Introduction The involvement of lymph nodes by metastatic tumors signifies the start of a new phase in the progress of a cancer. It indicates that through a succession of molecular…

Hemangiomas/Hemangioendotheliomas Definition Primary benign vascular tumors of lymph nodes. Pathogenesis Vascular neoplasms of lymph nodes are uncommon yet morphologically diverse, including multiple entities with a varied and sometimes confusing nomenclature…

Introduction A broad spectrum of vascular proliferations may involve lymph nodes, ranging from the benign vascular hyperplasias of some lymphadenopathies to the malignant vascular neoplasias of Kaposi sarcoma and angiosarcoma….

Inflammatory Pseudotumor of Lymph Nodes Definition Inflammatory pseudotumor (IPT) of lymph node is a histiocytic and fibroblastic non-neoplastic proliferation involving the lymph node connective tissue framework and associated with vascular…

Palisaded Myofibroblastoma Definition Benign mesenchymal lymph node tumor characterized by palisading spindle cells, stellate deposits of collagen (amianthoid fibers), and hemorrhage. Synonym Intranodal hemorrhagic spindle cell tumor with amianthoid fibers….

Lymphomas Associated with Acquired Immunodeficiency Syndrome (AIDS) Definition This is a heterogeneous group of Hodgkin lymphomas and non-Hodgkin lymphomas arising in persons with severe acquired immunodeficiency syndrome (AIDS) induced by…

Dendritic Cell Neoplasms Histiocytes have two broad functions: antigen processing and antigen presentation. In Chapter 77, the focus was on neoplasms derived from antigen-processing cells; that is, phagocytic histiocytes/macrophages. In…