PMC6038588_01
MRI with contrast shows multifocal T2 hyperintense abnormalities with the largest focus in the right frontal lobe.
CRIPA2018-5083234.001.jpg
PMC6038588_01_CRIPA2018-5083234.001.jpg
fig1
Brain magnetic resonance imaging (MRI) revealed a large confluent white matter T2-hyperintensity in the right frontal lobe with multifocal nodular enhancement of the left cerebral hemisphere (Figure 1).
(a) Abundant accumulation of parenchymal, vascular, and perivascular amyloid, hematoxylin and eosin stain, original magnification 100x. (b) Congo-red stain highlights the amyloid deposition in a parenchymal blood vessel that also shows perivascular lymphocytic infiltration, original magnification 200x. (c) Small intraparenchymal blood vessels with perivascular lymphoplasmacytic infiltrate, hematoxylin and eosin stain, original magnification 100x.
CRIPA2018-5083234.002.jpg
PMC6038588_01_CRIPA2018-5083234.002.jpg
fig2
A biopsy of the mass was performed and revealed extensive parenchymal lakes and vascular and perivascular deposition of amorphous, amyloid like material (Figure 2(a)). Congo-red positive staining and apple-green birefringence (not shown) of the amorphous material upon polarization confirmed that the amorphous material was amyloid (Figure 2(b)). Also present in the resected tissue were a number of small intraparenchymal blood vessels with perivascular lymphoplasmacytic infiltrates (Figure 2(c)).
(a) Perivascular infiltrate highlighting the lymphoplasmacytic appearance of the cells, hematoxylin and eosin stain, original magnification 600x. (b) Immunohistochemical stain for CD20 highlights a perivascular infiltrate of B-cells, original magnification 200x. (c) and (d) Positive staining of the tumor cells for lambda light chains but not for kappa light chains signifies lambda light chain restriction, in situ hybridization, original magnification 200X.
CRIPA2018-5083234.003.jpg
PMC6038588_01_CRIPA2018-5083234.003.jpg
fig3
Histologically, the monotonous populations of perivascular lymphoid cells demonstrated a lymphoplasmacytic appearance (Figure 3(a)). Immunohistochemical analysis demonstrated that the lymphoid cells were CD20 positive (Figure 3(b)). The more plasmacytoid appearing cells were CD138 positive and were shown to be lambda light chain restricted by kappa and lambda chromogenic in situ analysis (Figures 3(c) and 3(d)).