Anaplastic Lymphoma Kinase (ALK) protein expression by
Immunohistochemistry
A total of 54 cases were evaluated for ALK protein expression after
excluding 6 cases for technical reasons. ALK expression was mainly
cytoplasmic and granular in nature (Fig.1), nuclear positivity was not
seen. Some cases also showed intense membranous positivity and strong
positivity in the neuropil. ALK expression was heterogeneous in 17 out
of 54 (32%) cases. H-scoring was performed as described in the methods
and overall, 35 cases (65%) with an H-score of ≥100 showed moderate to
strong ALK positivity, whereas 19 cases (35%) with <100
H-score were negative (Fig.1).