Table 3.

Correlation between ALK Expression and RT-PCR for NPM-ALK in 11 ALK-Positive Lymphomas

ALK-positive lymphoma	Morphology	ALK expression pattern (ALKc)	NPM-ALK
1	Common type	Nuclear and cytoplasmic (large cells)	+
2	Common type	Nuclear and cytoplasmic (large cells)	+
3	Common type	Nuclear and cytoplasmic (mostly large cells)*	+
4	Common type	Nuclear and cytoplasmic (large cells)	+
5	Common type	Nuclear and cytoplasmic (large cells)	+†
6	Common type	Nuclear and cytoplasmic (mostly large cells)*	+
7	Common type	Cytoplasm restricted (large cells)	−
8	Giant cell type	Cytoplasm restricted (large cells)	−
9	Lymphohistiocytic	Nucleus restricted (mostly small cells)‡	+
10	Lymphohistiocytic	Nucleus restricted (mostly small cells)‡	+
11	Small cell type	Nucleus restricted (mostly small cells)‡	+

*A percentage (5 to 30%) of small cells with nucleus-restricted ALK positivity was also present.

^†RT-PCR was not performed in this case but conventional cytogenetic examination showed typical t(2;5).

^‡A small number of large anaplastic cells with nuclear plus cytoplasmic ALK expression was also detected.