Lymphoid neoplasms with plasmablastic differentiation

Overview of lymphoid neoplasms with plasmablastic differentiation

Lymphoid neoplasms with plasmablastic differentiation are a group of hematologic malignancies characterized by the presence of plasmablasts, which are immature plasma cells. These neoplasms are a subset of non-Hodgkin lymphomas and are often associated with immunodeficiency states, such as HIV/AIDS.

Classification

Lymphoid neoplasms with plasmablastic differentiation include several distinct entities, each with unique clinical and pathological features. The main types are:

• Plasmablastic lymphoma
• Primary effusion lymphoma
• ALK-positive large B-cell lymphoma
• Diffuse large B-cell lymphoma with plasmablastic features

Pathophysiology

These neoplasms arise from B cells that have undergone differentiation towards plasma cells. The transformation process involves genetic mutations and alterations in signaling pathways that lead to uncontrolled proliferation and survival of plasmablasts. Common genetic abnormalities include rearrangements of the MYC oncogene and mutations in genes involved in the NF-kB signaling pathway.

Clinical Presentation

Patients with lymphoid neoplasms with plasmablastic differentiation often present with rapidly growing masses, which can occur in various anatomical sites, including the oral cavity, gastrointestinal tract, and lymph nodes. Systemic symptoms such as fever, night sweats, and weight loss are also common.

Diagnosis

The diagnosis of these neoplasms is based on a combination of clinical, histological, and immunophenotypic features. Histologically, they are characterized by sheets of large cells with abundant cytoplasm and prominent nucleoli. Immunophenotyping typically shows expression of plasma cell markers such as CD138 and MUM1, with variable expression of B-cell markers like CD20.

Plasmablasts as seen under Wright stain

Treatment

The treatment of lymphoid neoplasms with plasmablastic differentiation often involves combination chemotherapy regimens similar to those used for other aggressive lymphomas. Antiretroviral therapy is crucial in patients with HIV-associated disease. The role of radiotherapy and hematopoietic stem cell transplantation is still being evaluated.

Prognosis

The prognosis for patients with these neoplasms is generally poor, with a high rate of relapse and progression despite aggressive treatment. Factors influencing prognosis include the patient's immune status, the extent of disease at diagnosis, and the specific genetic abnormalities present.

Related pages

• Non-Hodgkin lymphoma
• Plasma cell neoplasm
• HIV/AIDS