NK-T-Cell Non-Hodgkin’s Lymphoma
Before describing NK-T-cell non-Hodgkins lymphoma it is appropriate to define and discuss lymphoma. Lymphoma is a disease/blood cancer which results when DNA damage or changes occur to immune cells (lymphocytes of the immune system) that alters the behavior of the cells. The damage results in the abnormal production of proteins that prevents the cells from dying when they should, or causes sustained rapid cell division that produces more of its kind. Theses malignant cells then may accumulate to form tumors that may spread to other areas of the lymphatic system, such as the spleen or bone marrow. Lymphoma can also spread, or first appear outside the lymphatic system. Many lymphomas arise, or present, in non-lymphoid sites such as the skin and gastrointestinal track -- these are called extranodal lymphomas. Matt suffered from extranodal lymphoma which initially presented in his skin and ultimately attacked his brain and central nervous system.
Lymphomas are categorized as either Hodgkin’s or non-Hodgkin’s lymphomas. The non-Hodgkin lymphomas (NHLs) are a diverse group of blood cancers that include any kind of lymphoma except Hodgkin's lymphomas, which are cancers of unique malignant cells known as Reed-Sternberg cells. Types of NHL vary significantly in their severity, from indolent (i.e., slow to develop) to very aggressive, with NK-T-cell lymphoma being one of the most rare and aggressive.
NK T- Cell Lymphoma
Extranodal NK T-cell lymphoma is a rare and aggressive lymphoma marked by extensive necrosis (localized death of living cells) and angioinvasion (presence of tumor emboli or tumor masses), most often presenting in extranodal sites such as the nasal or paranasal sinus region, the palate, trachea, skin, and gastrointestinal tract. Hemophagocytic syndrome may occur. In most cases, EBV genomes are detectable in the tumor cells and immunophenotyping shows CD56 positivity. In addition to chemotherapy for NK T-cell lymphoma, the increased risk of central nervous system (CNS) involvement and of local recurrence has led to recommendations for radiation therapy locally, often prior to the start of chemotherapy. The highly aggressive course, with poor response and short survival with standard therapies, has led some investigators to recommend bone marrow or peripheral stem cell transplantation consolidation.