Discussion
WM is a non-Hodgkin lymphoma characterized by the invasion of
lymphoplasma cells into bone marrow and IgM-monoclonal proteinemia. The
incidence rate of WM is 3–4 cases per million persons per year,
accounting for only 1% of lymphomas1. WM causes AL
amyloidosis in only 3% of WM cases2. Information
about cutaneous manifestations of WM-related AL amyloidosis is limited.
AL amyloidosis affects various organs/tissues including the kidneys,
heart, nerves, and skin3. Cutaneous manifestations are
dependent on the histological area where amyloid protein deposits;
previous literature reported that protein deposition in vessel walls,
folliculosebaceous units, and the epidermis/dermis causes purpura,
alopecia, and papules/nodules, respectively4. Purpura
is reportedly caused by vessel fragility due to the deposition and
abnormality of the coagulation/fibrinolysis system5.
Our case, however, presented with papules/nodules and not purpura. The
cutaneous manifestation was considered to have developed by the
following mechanisms: i) abnormalities of factors controlling
coagulation and fibrinolysis were not severe enough to cause the
collapse of the coagulation/fibrinolysis system; ii) the vascular
endothelial cells were not destroyed by the deposition, compatible with
the histopathological findings that vascular endothelial cells were not
affected by the deposition; and iii) marked deposition around vessels in
the dermis and subcutis caused papules/nodules.
This case report provides evidence that WM may cause cutaneous
manifestations represented as papules/nodules through the development of
AL amyloidosis.
Acknowledgement: None
Statement of Ethics: This study protocol was approved by The
Ethics Committee of The Jikei University School of Medicine and the
patient provided written informed consent.