Solitary plasmacytoma with minimal bone marrow involvement
Solitary plasmacytoma with minimal bone marrow involvement refers to a type of plasmacytoma with bone marrow cytology positive for monoclonal plasma cell infiltration.
In order to fulfil the International Myeloma Working Group criteria for the diagnosis of solitary plasmacytoma with minimal bone marrow involvement patients must have:
- a biopsy-proven solitary lesion of bone or soft tissue with evidence of clonal plasma cells
- the clonal bone marrow plasma cells constitutes <10% cellularity
- a normal skeletal survey and MRI or CT of the spine and pelvis, except for the primary solitary lesion
- an absence of a myeloma defining event such as hypercalcaemia, renal insufficiency, anaemia or other bone lesions
As per the International Myeloma Working Group criteria patients must have a normal skeletal survey and MRI or CT of the pelvis and spine, other than the primary solitary lesion.
Treatment and prognosis
In contrast to solitary plasmacytoma the progression rate to multiple myeloma is much higher in patients with solitary plasmacytoma with minimal bone marrow involvement (60% for bone and 20% for soft tissue in the next 3 years) 1.
- 1. Rajkumar SV, Dimopoulos MA, Palumbo A, Blade J, Merlini G, Mateos MV, Kumar S, Hillengass J, Kastritis E, Richardson P, Landgren O, Paiva B, Dispenzieri A, Weiss B, LeLeu X, Zweegman S, Lonial S, Rosinol L, Zamagni E, Jagannath S, Sezer O, Kristinsson SY, Caers J, Usmani SZ, Lahuerta JJ, Johnsen HE, Beksac M, Cavo M, Goldschmidt H, Terpos E, Kyle RA, Anderson KC, Durie BG, Miguel JF. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. (2014) The Lancet. Oncology. 15 (12): e538-48. doi:10.1016/S1470-2045(14)70442-5 - Pubmed