Characterization of circulating myeloma tumor cells by next generation flowcytometry in scleromyxedema patient: a case report.

Taha, Ruba Y; Hasan, Saba; Ibrahim, Firyal; Chantran, Yannick; Sabah, Hesham El; Sivaraman, Siveen; Bozom, Issam Al; Sabbagh, Ahmad Al; Garderet, Laurent; Omri, Halima El

INTRODUCTION Scleromyxedema (rare cutaneous mucinosis), is characterized by the formation of lichenoid papules and presence of Serum monoclonal IgG in most cases, or all; after repeated testing. PATIENT CONCERNS The patient is a 51-year-old male presented with thick, disfiguring elephant-like erythematous skin folds over the forehead, papular shiny eruptions over ears and trunk and waxy erythematous papules over arms and hands without dysphagia or respiratory or neurologic symptoms DIAGNOSIS: : Skin biopsy from right arm was consistent with scleromyxedema. Serum cryoglobulin was reported negative. Complete blood count and routine blood biochemistry were normal. Thyroid function tests were normal. Serum protein electrophoresis and immunofixation showed monoclonal band of 14.5 g/L typed as IgG lambda. INTERVENTIONS Our patient was refractory to lenalidomide however improved clinically on immunoglobulins infusions on monthly basis without change in the MGUS level. OUTCOMES NGF analysis revealed approximately 0.25% Lambda monotypic plasma cells in the bone marrow expressing CD38, CD138, and CD27 with aberrant expression of CD56 and were negative for CD45, CD19, CD117, and CD81. We also detected 0.002% circulating plasma cells (PCs) in peripheral blood. CONCLUSION The immunophenotype of circulating tumor cells (CTCs) remain close to the malignant PCs phenotype in the BM. Hence, we report NGF approach as a novel diagnostic tool for highly sensitive MRD detection in plasma cell dyscrasias including scleromyxedema.