S0120, Studying Blood and Bone Marrow Samples From Patients With Monoclonal Gammopathy of Undetermined Significance, Multiple Myeloma, or Plasmacytoma

DISEASE CHARACTERISTICS: * Diagnosis of one of the following plasmaproliferative diseases: * Monoclonal gammopathy of undetermined significance (MGUS) * Asymptomatic multiple myeloma * Solitary plasmacytoma * Other plasma cell dyscrasias * Disease does not require therapy * Willing to submit research samples for gene expression analysis and immunologic assessment PATIENT CHARACTERISTICS: Age * Not specified Performance status * Zubrod 0-2 Life expectancy * Not specified Hematopoietic * Not specified Hepatic * Not specified Renal * Not specified Other * No other malignancy within the past 2 years except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or adequately treated stage I or II cancer from which the patient is currently in complete remission PRIOR CONCURRENT THERAPY: Biologic therapy * No prior biologic therapy for this disease Chemotherapy * No prior chemotherapy for this disease Endocrine therapy * No prior endocrine therapy for this disease Radiotherapy * No prior radiotherapy for this disease Surgery * No prior surgery for this disease Other * Prior or concurrent bisphosphonates allowed