In CD13+ cases, care must be taken to rule out a myeloid process as CD30 can be expressed in granulocytic sarcoma.103 Rare cases of myeloid antigen-positive tumours with features of anaplastic large-cell lymphoma (CD30+, EMA+, ALK+), CD56 expression, and a TPM4 (tropomyosin 4)-ALK fusion have been described.115. The gene discussed is ALK; the disease is granulocytic sarcoma.