Central nervous system ALK-negative anaplastic large cell lymphoma with IRF4/DUSP22 rearrangement

Figures

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  Fig. 1. Initial axial, contrast-enhanced T1-weighted, magnetic resonance image demonstrating enlargement and amorphous enhancement involving the cingulate gyrus and corpus callosum, extending across the midline (a). There was also confluent periventricular white matter T2/FLAIR hyperintensity (b). Repeat imaging 3 months later showed multiple new contrast-enhancing masses (c) and progression of T2/FLAIR hyperintensity (d)

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  Fig. 2. Biopsy of the corpus callosum lesion showing large pleomorphic cells, admixed with medium to small lymphocytes, diffusely infiltrating brain parenchyma with perivascular accentuation (arrows) (a, 200 ×). The cells have irregular nuclear contours (b, 400 ×) with scattered hallmark cells (inset 600 ×); mitotic figures are easily seen (arrowheads) (c, 600 ×). On immunohistochemistry, the cells are positive for CD30, with many showing strong membranous and Golgi staining (d, 400 ×); large cells negative for CD30 are likely reactive astrocytes, endothelial cells and/or histiocytes. The tumor cells are also positive for CD2 (e, 400 ×) and granzyme B (f, 400 ×). ALK-1 is negative (g, 400 ×). The MIB-1 labeling index is over 90% (h, 400 ×)

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  Fig. 3. TCRG clonal product (arrows at 245 bp and 218 bp) with two of the primer sets using the BIOMED-2 protocol (a). Fluorescence in situ hybridization demonstrates IRF4/DUSP22 rearrangement (arrows) with an extra copy of 3′IRF4 in the large cells (arrowheads) (b)