Histology, immunohistochemistry, and T-cell gene rearrangement studies were supportive of a CD 30-positive ALK-1 negative anaplastic large cell lymphoma.
Abnormalities of chromosome 2p23 with expression of ALK1 and p80 occur in both inflammatory myofibroblastic tumor (IMT) and anaplastic large cell lymphoma.
However, CD13 positivity has not previously been described in a case of CD30+ (ALK-1+) anaplastic large-cell lymphoma of presumed null-cell origin without histiocytic differentiation.