Which characteristic is NOT typical of follicular lymphoma?

• A. Expression of CD19 and CD10
• B. Presence of aggressive symptoms early in the disease
• C. Common occurrence in lymph node germinal centers
• D. Kappa light chain restriction

Answer: (B)

Follicular lymphoma is a type of non-Hodgkin lymphoma that typically presents with certain immunophenotypic and clinical characteristics. It is often associated with the expression of CD19 and CD10 on neoplastic B-cells, which are important markers in identifying this type of lymphoma. The presence of these markers is quite characteristic of follicular lymphoma, as they correspond to the cells' derivation from germinal center B-cells.

Follicular lymphoma also frequently occurs in lymph node germinal centers, where these malignant cells originate. This localization within the germinal centers is significant for understanding the pathophysiology of this lymphoma type.

Kappa light chain restriction refers to the phenomenon where the malignant B-cells produce predominantly one type of immunoglobulin light chain (either kappa or lambda), which is typical in many B-cell malignancies, including follicular lymphoma. This light chain restriction can often be detected through immunohistochemical studies or flow cytometry.

In contrast, the presence of aggressive symptoms early in the disease is not typical of follicular lymphoma. This lymphoma usually has an indolent course, meaning that it often progresses slowly and may not present with aggressive symptoms until later stages or at transformation to a more aggressive form.