Anaplastic Large Cell Lymphoma
The tumor cells are positive for CD30 in a membranous and paranuclear Golgi-type dot pattern. Majority of the systemic cases (70% to 80%) carry t(2;5)(p23;q35) translocation resulting in the formation of NPN-ALK chimeric protein that can be detected by immunohistochemistry. Additional findings are T-cell receptor gene rearrangements and expression of pan-lymphoid and some T-cell related markers. B-cell markers are negative.