Splenic marginal zone lymphoma

Splenic Marginal Zone Lymphoma (SMZL) is a rare type of B-cell lymphoma that primarily affects the spleen, bone marrow, and sometimes the blood. It is a slow-growing, or indolent, lymphoma that belongs to the group of non-Hodgkin lymphomas (NHL). SMZL is characterized by the accumulation of malignant B cells in the marginal zone of the spleen, leading to splenomegaly (enlargement of the spleen). This article provides an overview of the clinical features, diagnosis, and treatment of Splenic Marginal Zone Lymphoma.

Clinical Features

Patients with SMZL may present with a variety of symptoms, although some individuals may be asymptomatic and diagnosed incidentally during a physical examination or imaging studies. Common symptoms include:

• Splenomegaly: Enlargement of the spleen is the most characteristic feature of SMZL.
• Anemia: A decrease in red blood cells can cause fatigue, weakness, and pallor.
• Thrombocytopenia: A low platelet count can lead to increased bruising and bleeding.
• Neutropenia: A decrease in neutrophils, a type of white blood cell, can increase the risk of infections.
• B symptoms: Including fever, night sweats, and weight loss, although these are less common in SMZL compared to other types of lymphoma.

Diagnosis

The diagnosis of SMZL involves a combination of clinical evaluation, laboratory tests, imaging studies, and histopathological examination. Key diagnostic procedures include:

• Blood tests: To assess the complete blood count (CBC), liver and kidney function, and to detect the presence of abnormal lymphocytes.
• Imaging studies: Such as ultrasound or CT scans of the abdomen, to evaluate the size of the spleen and detect any lymphadenopathy (enlarged lymph nodes).
• Bone marrow biopsy: To examine the involvement of bone marrow by the lymphoma.
• Splenectomy: Removal of the spleen followed by a detailed examination of the tissue can confirm the diagnosis of SMZL and help in staging the disease.

Treatment

The treatment of SMZL is tailored to the individual patient, depending on the stage and symptoms of the disease. Options include:

• Watchful waiting: For asymptomatic patients, immediate treatment may not be necessary, and regular monitoring is conducted.
• Splenectomy: Surgical removal of the spleen can provide symptom relief and improve blood counts.
• Chemotherapy: In cases where the disease is more aggressive or symptomatic, chemotherapy may be used.
• Rituximab: A monoclonal antibody that targets CD20-positive B cells, often used in combination with chemotherapy.
• Radiotherapy: In selected cases, for localized disease or for palliation.

Prognosis

The prognosis of SMZL is generally favorable, with a median survival of over 10 years. However, outcomes can vary based on the presence of adverse prognostic factors, such as high LDH levels, anemia, and high-risk genetic abnormalities.

Epidemiology

SMZL is a rare disease, accounting for less than 2% of all non-Hodgkin lymphomas. It typically affects middle-aged to elderly individuals, with a slight male predominance.

See Also

• Lymphoma
• Non-Hodgkin Lymphoma
• B-cell Lymphoma
• Splenomegaly