A case of a 70-year-old man presenting with exsudative enteropathy due to light-chain-associated amyloidosis is reported. The diagnosis of systemic mastocytosis associated with IgG/λ plasma cell myeloma and secondary generalised amyloidosis was carried out by morphological evaluation of bone marrow biopsy. The c-kit point mutation D816Y was detected by molecular analysis. Two years before, a cystadenolymphoma of the left parotid gland had been removed. A moderate increase of loosely scattered spindle-shaped mast cells, a subpopulation of them expressing CD25, an antigen that is not expressed by normal or reactive mast cells, was shown by retrospective analysis carried out on an intraparotideal lymph node. The c-kit mutation D816Y was shown by the molecular analysis of the lymph node. In summary, the notion that systemic mastocytosis may very rarely be associated with B cell neoplasms and that neoplastic mast cell infiltrates may be obscured because of only a minimal increase of atypical mast cells, which are outnumbered by other non-neoplastic cells in the same tissue, is supported by this case. This finding was preliminarily termed “occult” mastocytosis.
- AHNMD, associated clonal haematological non-mast cell lineage disease
- PNA, peptide nucleic acid
- SM-AHNMD, systemic mastocytosis associated clonal haematological non-mast cell lineage disease
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
Funding: This study was in part supported by the Fortüne Förderprogramm, Universität Tübingen (F1461141), Tübingen, Germany.
Competing interests: None declared.