Plasma-cell proliferation · histology

A plasmacytoma is a neoplastic plasma-cell proliferation; the term “solitary” requires staging.

Identify the specimen, assess architecture and correlate morphology with immunostains.

The field contains a dense plasma-cell population; nuclei are often eccentric with condensed chromatin.

A plasma-cell neoplasm may be localised or part of myeloma; the photograph does not distinguish these settings.

Reactive plasmacytosis and other lymphoid proliferations require immunophenotypic and clonality assessment.

Assess monoclonal protein and bone, renal or haematological involvement; complete marrow assessment and appropriate imaging.

Assess organ involvement: anaemia, renal failure, hypercalcaemia or bone lesions; their severity cannot be measured from this section.

Plasma-cell abundance alone does not prove clonality; one section cannot distinguish solitary plasmacytoma from myeloma.

Recognise plasma cells, confirm clonal proliferation and establish extent before classifying disease.

• Caers J et al. Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel. J Hematol Oncol, 2018 ↗
• MD Anderson Cancer Center. Solitary Plasmacytoma(Bone and Extramedullary), algorithme institutionnel, 2024 ↗

Documentary review: 2026-10-15