Anaplastic large-cell lymphoma

Anaplastic_large-cell_lymphoma

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  Anaplastic large-cell lymphoma under very high magnification
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  Anaplastic large-cell lymphoma CD30 positive

Anaplastic Large-Cell Lymphoma

Anaplastic large-cell lymphoma (ALCL) is a type of non-Hodgkin lymphoma that is characterized by the presence of large, atypical lymphoid cells. It is a rare form of lymphoma that can occur in both children and adults. ALCL is classified as a T-cell lymphoma, meaning it originates from T lymphocytes, a type of white blood cell that plays a crucial role in the immune system.

Classification

ALCL is divided into two main types based on the presence or absence of a specific genetic abnormality involving the anaplastic lymphoma kinase (ALK) gene:

• ALK-positive ALCL: This type is more common in children and young adults. It is characterized by the presence of a translocation involving the ALK gene, which leads to the expression of an abnormal ALK protein that promotes cell growth and survival.

• ALK-negative ALCL: This type is more common in older adults and does not have the ALK gene rearrangement. It tends to have a more aggressive clinical course compared to ALK-positive ALCL.

Clinical Presentation

Patients with ALCL may present with a variety of symptoms, including:

• Lymphadenopathy: Swelling of the lymph nodes, which may be painless.
• B symptoms: Fever, night sweats, and weight loss.
• Extranodal involvement: ALCL can affect organs outside the lymphatic system, such as the skin, liver, lungs, and bones.

Diagnosis

The diagnosis of ALCL is made through a combination of clinical evaluation, imaging studies, and biopsy of affected tissue. Histological examination reveals large, pleomorphic cells with abundant cytoplasm and horseshoe-shaped nuclei. Immunohistochemistry is used to detect the expression of CD30, a marker that is typically positive in ALCL cells.

Treatment

The treatment of ALCL depends on the subtype and stage of the disease. Common treatment options include:

• Chemotherapy: Regimens such as CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) are commonly used.
• Targeted therapy: For ALK-positive ALCL, ALK inhibitors such as crizotinib may be used.
• Radiation therapy: May be used in certain cases, especially for localized disease.
• Stem cell transplantation: Considered in cases of relapsed or refractory ALCL.

Prognosis

The prognosis of ALCL varies depending on the subtype and other factors such as age and overall health. ALK-positive ALCL generally has a better prognosis compared to ALK-negative ALCL. Long-term survival rates are higher in children and young adults compared to older patients.

Related Pages

• Non-Hodgkin lymphoma
• T-cell lymphoma
• Lymphadenopathy
• Chemotherapy