Multiple myeloma (MM) is a monoclonal B-cell malignancy, which originates theoretically in lymph node germinal centers but locates and expands in bone marrow. It represents 10% of all the hematopoietic cancers, with a great variability in clinical presentation, response to therapy and survival duration. In more than 1/3 of cases, MM can be preceded by a phase of monoclonal gammopathy of uncertain significance (MGUS). At the extreme it can evolve in plasma blast acute leukemia.

malignant myeloma cells are long-lived cells with morphological features varying from normal to dystrophic considering size of the cells, presence of nucleolar structures and aspect of the chromatin. Immunophenotype includes inconstant expression of CD56, CD38, CD40 and CD138.

del(13q) is detected in 15-20% of MM patients by conventional karyotype and in 33-52% of cases by FISH analysis

-13/del(13q) appears as one of the main prognostic factors with ?2-microglobulin serum level and the percentage of bone marrow plasma cells. Patients with del(13q) have a significantly lower event-free survival, overall survival and complete remission duration, either in standard-dose or in high dose therapy protocols.