Diagnostic Approach to Solitary Plasmacytoma

Introduction to Diagnostic Criteria

The International Myeloma Society recommends that a diagnosis of solitary plasmacytoma be considered in patients with a single lesion and no evidence of systemic disease, with biopsy-proven clonal plasma cells and no other signs of multiple myeloma 1, 3
The presence of a solitary osteolytic lesion, such as a 20mm frontal left lesion, can be consistent with a solitary plasmacytoma or the initial manifestation of multiple myeloma, according to the Annals of Oncology 1, 2, 3

A solitary osteolytic lesion in the skull, such as a 20mm lesion, can correspond to a solitary plasmacytoma or be the initial manifestation of multiple myeloma, as suggested by the Annals of Oncology 1, 2, 3
The American College of Hematology suggests that irregular cortical and diploe hypodensity on CT scans are compatible with lytic lesions related to plasma cell proliferation 1, 3

The European Society for Medical Oncology recommends that serum free light chain assays be used to evaluate patients with suspected plasma cell disorders, with an abnormal ratio suggesting monoclonal protein production 4, 5
Elevated serum free light chains, such as kappa or lambda, can indicate a plasma cell disorder, according to Praxis Medical Insights 4, 5

The International Myeloma Society recommends that a complete bone series, including skull, spine, pelvis, and long bones, be performed to evaluate for additional lesions, as suggested by the Annals of Oncology 1, 3
Magnetic resonance imaging (MRI) of the spine can detect additional lesions not visible on plain radiographs, as recommended by the Annals of Oncology 1, 3

The presence of ≥10% clonal plasma cells in the bone marrow is a diagnostic criterion for multiple myeloma, according to the International Myeloma Society 5
The CRAB criteria (calcium, renal, anemia, bone) are used to diagnose symptomatic multiple myeloma, with the presence of one or more of these criteria indicating active disease, as suggested by the Annals of Oncology 1, 2, 3

The American Society of Clinical Oncology recommends that patients with solitary plasmacytoma receive local radiation therapy, with a typical dose of 40-50 Gy, as suggested by the Annals of Oncology 1, 3
The European Society for Medical Oncology suggests that patients with multiple myeloma receive induction therapy, such as bortezomib, lenalidomide, and dexamethasone (VRd), followed by autologous stem cell transplantation, as recommended by the Annals of Oncology 2, 6

The International Myeloma Society recommends that patients with solitary plasmacytoma or multiple myeloma be monitored regularly, with serum free light chain assays, electroforesis, and imaging studies, to evaluate response to treatment and detect progression, as suggested by Praxis Medical Insights 4, 5