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Author: Admin | 2025-04-28
Plasma cell neoplasmsDiagnosis in shortPlasma cell neoplasm. H&E stainLM dyscohesive plasmacytoid cells (abundant cytoplasm, eccentrically placed nucleus), often prominent perinuclear hof, +/-nucleoli, +/-Russell bodies, +/-Dutcher bodiesLM DDx lymphoplasmacytic lymphoma, neuroendocrine carcinoma, poorly differentiated carcinoma, othersIHC CD138 +ve, CD56 +ve, CD45 -ve/+ve, CD79a +veSite bone - bone marrowAssociated Dx renal failure, myeloma cast nephropathyBlood work +/-anemia, +/-hypercalcemiaRadiology +/-lytic bone lesionsPrognosis poorClin. DDx metastatic diseasePlasma cell neoplasms arise from plasma cells. They are encountered by anatomical pathologists on occasion.Plasma cell myeloma, and plasmacytoma (solitary myeloma)[1] redirect to this article.GeneralMalignancy derived from the plasma cells.Prognosis: poor.Common primary bone tumour in adults.Clinical:[2]Bence Jones protein (urine).Abnormal protein electrophoresis (monoclonal gammopathy, dysproteinemia, paraproteinemia).Note:Plasmacytoma = histology of multiple myeloma; to diagnose multiple myeloma other (non-pathology) criteria are needed.Classified by site:Medullary.Extramedullary - usu. upper aerodigestive tract.[3]Multiple myelomaDiagnosis requires the following:[4]Clonal plasma cells. Must >10% if on bone marrow biopsy.Monoclonal protein, i.e. paraprotein, in serum or urine.End-organ damage thought to be due to the neoplasm - mnemonic CARL:Calcium (in the serum) is elevated.Anemia.Renal failure.Lytic bone lesions.Note: CRAB (calclium, renal failure, anemia, bony lesions) is another mnemonic.[5]MicroscopicFeatures (plasmacytoma):Abundant eosinophilic cytoplasm.Eccentrically placed nucleus.Usually with "clock face" morphology."Clock face" morphology = chromatin clumps around the edge of the nucleus, like the numbers on a clock face.May have nucleoli.Russell bodies:Eosinophilic, large (10-15 micrometres), homogenous immunoglobulin-containing inclusions.Dutcher bodies - intranuclear crystalline rods.Dutcher bodies are PAS stain +ve.[6]Prominent perinuclear hof - cytoplasmic crescent shaped lucency adjacent to the nuclear membrane (due to large Golgi apparatus); nucleus has a "bib".DDx:Neuroendocrine carcinoma - nucleus often has a plasmacytoid (plasma cell-like) appearance.Lymphoplasmacytic lymphoma (AKA Waldenström's macroglobulinemia).Syphilis.ImagesCase PCN - low mag. PCN - intermed. mag. PCN - high mag. PCN - very high mag. Other cases Plasmacytoma. (WC) Skull base plasmacytoma, higher magnification (WC/jensflorian) Plasmacytoma smear (WC/jensflorian) Leptomeningeal plasmacytoma, frozen section (WC/jensflorian) wwwVarious images (hematologylibrary.org).Multiple myeloma (upmc.edu).[7]Russell bodies Russell
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