Diffuse Large B Cell Lymphoma (DLBCL): This is the most common type of non-Hodgkin lymphoma, and CD10 positivity is seen in a subset of cases, particularly those with a germinal center B cell-like (GCB) subtype. The presence of B cells in pleural effusion suggests a possible lymphomatous involvement.

Follicular Lymphoma: Although less common than DLBCL, follicular lymphoma can also present with CD10 positive B cells. It typically has a more indolent course but can involve unusual sites like the pleura.
Burkitt Lymphoma/Leukemia: This aggressive B cell malignancy is CD10 positive and can present in various extranodal sites, including the pleura, though it is less common.

Mantle Cell Lymphoma: Although typically CD10 negative, a small subset of mantle cell lymphomas can express CD10. Given its aggressive nature and potential for extranodal involvement, it's crucial not to miss this diagnosis.
Acute Lymphoblastic Leukemia (ALL): Some cases of ALL, particularly those of B cell lineage, can be CD10 positive. Involvement of the pleura can occur, and missing this diagnosis could have severe consequences due to the aggressive nature of ALL.

Lymphoblastic Lymphoma: A rare and aggressive form of non-Hodgkin lymphoma that can be CD10 positive. It is more commonly associated with T cell lineage but can rarely be of B cell origin.
Primary Effusion Lymphoma: A rare type of lymphoma associated with human herpesvirus 8 (HHV-8), typically seen in immunocompromised patients. While it is usually CD10 negative, rare cases might express CD10, making it a consideration in the differential diagnosis of B cell lymphomas in pleural effusions.