Systemic Mastocytosis Accompanied by a Non-Secretory Plasma Cell Dyscrasia and Nephrotic Syndrome-Level Proteinuria in a 76-Year-Old Patient

Abstract

We report here the interesting case of a 76-year-old man with severe proteinuria who was diagnosed with systemic mastocytosis accompanied by a clonal non-mast-cell lineage haematological disorder (a non-secretory plasma cell dyscrasia). This is a unique report of systemic mastocytosis with a non-secretory plasma cell dyscrasia and nephrotic syndrome. The pathophysiological relevance between these entities along with the probability of occult amyloidosis is discussed.

Systemic mastocytosis with renal light chain amyloidosis: associated non-mast cell disorder or concurrent disease

“…The case is unique as it is the first to include renal AL in conjunction with SM. Previously, Papadopoulou et al reported a case of nephrotic range proteinuria in conjunction with SM, and although amyloidosis was suspected, it was not proven given the heightened risk of renal biopsy in the context of the coagulopathy present at the time [13]. Although it is possible that AL amyloid was the culprit in that case, other etiologies of nephrotic proteinuria are possible including secondary amyloidosis as reported by Sotlar et al [11].…”

“…As shown in Table 1, we identified a total of 12 cases of SM diagnosed before, after, or simultaneously with a PCN. Eight cases were diagnosed simultaneously where the associated PCN either monoclonal gammopathy of unknown significance (MGUS), smoldering multiple myeloma (SMM), or plasma cell myeloma (PCM) [8][9][10][11][12][13][14][15]. On the other hand, SM preceded light chain deposition NA, not available disease (LCDD) or PCM in two cases [16,17], while MGUS preceded SM in the remaining two cases [18,19].…”