Plasma cell myeloma-related serous cavity effusion: Cytological and clinical insights from two cases

Disseminated plasma cell myeloma is an uncommon phenomenon and is characterized by a disease biology that is distinct from medullary disease. These are characterized by high-risk cytogenetic abnormalities and aggressive disease course. Involvement of body fluids by plasma cell dyscrasias poses a diagnostic challenge owing to morphological overlap with other reactive or clonal conditions. Clinical history, along with diagnostic adjuncts such as flow cytometry, cell block, and immunohistochemistry, is an essential tool for comprehensive evaluation, diagnosis, and eventual therapeutic decision-making. We discuss two cases of body fluids involved in plasma cell dyscrasia along with relevant diagnostic dilemmas and review of literature.