Multiple Myeloma Clinical Features

Classic diagnostic tetrad of end-organ damage caused by monoclonal malignant plasma cell proliferation.

Malignant plasma cells clone in bone marrow and overproduce monoclonal immunoglobulin (M-protein spike) and osteoclast-activating cytokines (RANKL).

Systematic Breakdown

Serum calcium > 11 mg/dL resulting from widespread osteoclast bone resorption induced by neoplastic plasma cells.

Myeloma cast nephropathy (toxic monoclonal light chains precipitate with Tamm-Horsfall protein to obstruct tubules).

Hemoglobin < 10 g/dL due to marrow replacement by plasma cells and decreased renal erythropoietin production.

Painful osteolytic skeletal lesions (skull, spine, ribs) on skeletal survey without osteoblastic reactive sclerosis.

High-Yield Clinical Pearls & Exam Tips

Serum Protein Electrophoresis (SPEP): Shows monoclonal immunoglobulin 'M-spike' (most commonly IgG ~50%, followed by IgA ~20%).
Peripheral Blood Smear: Shows Rouleaux formation (RBCs stacked like coins due to elevated paraprotein neutralizing negative surface charges).
Urine Protein: Dipstick will be NEGATIVE for Bence-Jones light chains (dipstick detects only albumin); must order 24h urine protein electrophoresis (UPEP).

Related Pharmaceuticals

Bortezomib Lenalidomide Dexamethasone Daratumumab

Related Clinical Conditions

Multiple Myeloma MGUS Smoldering Myeloma AL Amyloidosis

Authoritative Sources: Robbins & Cotran Pathologic Basis of Disease 10e · International Myeloma Working Group (IMWG) Criteria