Which type of neoplasm is characterized by the presence of plasma cells?

Multiple myeloma is characterized by the proliferation of abnormal plasma cells, which are a type of white blood cell responsible for producing antibodies. In this neoplasm, these plasma cells accumulate in the bone marrow and can lead to various clinical manifestations, such as bone pain, anemia, increased serum protein levels, and renal dysfunction due to excessive production of paraproteins. The presence of these abnormal plasma cells is the defining feature of multiple myeloma, distinguishing it from other types of neoplasms that may involve different cell types or mechanisms of tumorigenesis.

In contrast, lymphoma primarily involves lymphocytes and can present with swollen lymph nodes or systemic symptoms, but it does not feature a predominance of plasma cells. Squamous cell carcinoma originates from squamous epithelial cells and is not associated with plasma cell proliferation. Adrenal carcinoma arises from the adrenal glands and is characterized by features related to adrenal cortical cells, rather than plasma cells. Thus, the unique association of plasma cells with multiple myeloma supports its identification as the correct answer in this context.