Conclusion:
This unique case associate two complications of a marginal zone lymphoma
with plasmacytic differentiation and IgM paraprotein. This observation
underlines the need to search for a B lymphoproliferative disorder after
an histological CSH diagnosis and to hypothesize that a
B-lymphoproliferative disorder with plasmacytic differentiation and
paraprotein secretion other than WM can induce neurological
presentations similar to BNS.
Fig1 Cerebral MRI. Leptomeningeal contrast enhancement in T1
Gadolinium sequence before treatment (arrow) (1A). Disappearance of the
leptomeningeal contrast enhancement in T1 Gadolinium sequence after
treatment (1B). Hypersignal lesions in the supra-tentorial white matter
in T2 FLAIR sequence before treatment (arrow) (1C). Stabilization of
hypersignal lesions in the supra-tentorial white matter in T2 FLAIR
sequence after treatment (arrow) (1D).
Fig2 Colon biopsy. Submucosal clusters of histiocytes with
crystalline eosinophilic cytoplasm inclusions (2A: HPS x 2.5, 2B: HPS x
40)
Fig3 Bone marrow biopsy. Hypercellular bone marrow with a
discret lymphoid infiltrat (arrow) (3A: HPS x 2.5). Histiocytes with
abundant crystalline eosinophilic cytoplasmic inclusions were
identified, scattered or in clusters (3B: HPS x 40). The lymphoid
infiltrate is made of a mixture of a B and T lymphocytes (3C: CD20 x 5,
3D: CD3 x 5). The plasma cells represented 5 to 10% of the bone marrow
cellularity (3E: CD138 x 5).
Fig4 Lymph node biopsy. Massive infiltration by the same
crystalline histiocytes as observed in colon biopsy and bone marrow,
associated with small lymphoid nodules at the periphery of the lymph
node (4A: HPS x 2.5). The crystalline histiocytes are admixed with
numerous plasma cells (4B: HPS x 40).