VII.D.001

Anaplastic large cell lymphoma. T-cell type. Lymph node biopsy. H & E. Infiltrate of malignant lymphocytes with multiple nucleoli and sometimes abundant cytoplasm. This lymphoma has a varied morphologic appearance but virtually all cases display a proportion of cells (hallmark cells) with horseshoe nuclei or multiple peripheral nuclei in a wreath shape. The arrow points to an example of a hallmark cell.

VII.D.002

Anaplastic large cell lymphoma: CD30 immunostain. Lymph node biopsy. The neoplastic lymphocytes in this type of lymphoma are strongly positive for the presence of CD30 on their surface, an activation marker expressed in this type of lymphoma.

VII.D.003

Anaplastic large cell lymphoma: anaplastic lymphoma kinase (ALK) immunostain. Lymph node biopsy. This lymphoma is strongly positive when examined for its content of ALK. Here we see a case with strong cytoplasmic staining. In other cases nuclear as well as cytoplasmic staining may be evident.

VII.D.004

Angiocentric T/NK cell lymphoma, nasal type. (A) H&E stain. Lymphoma cells may range from large to small with irregular nuclei. Nucleoli are inconspicuous in the small cells but overt in the larger cells. Cytoplasm is abundant and usually clear or pale. Mitotic figures are usually evident. Apoptotic bodies and necrosis is often present. Fibrinoid changes in blood vessel walls can occur. Involvement is diffuse but angiocentric and angionecrotic patterns may be present. (B) In situ hybridization for Epstein-Barr virus early RNA expression (EBER) is evident by nuclear brownish reaction product. (C) T-cell intracellular antigen (TIA-1) immunostain indicates brownish cytoplasmic reaction product confirming a cytotoxic T-cell/NK-cell phenotype.

VII.D.005

Angioimmunoblastic T-cell lymphoma. Lymph node biopsy. H & E. Low magnification. Prominent vascular proliferation (pink areas) with pleomorphic lymphoid infiltrate showing cytologic dysplasia between the vascular channels.

VII.D.006

Angioimmunoblastic T-cell lymphoma. Lymph node biopsy. H&E stain. Higher magnification. Cellular pleomorphism and atypia is more evident. Admixed scattered, larger cells representing B-cell immunoblasts are also seen. Plasma cells may also be prominent focally in some cases.

VII.D.007

Angioimmunoblastic T-cell lymphoma. CD45RO immunostain (reddish-brown cytoplasmic color reaction) demonstrates the T-cell origin for most of the tumor cells.

VII.D.008

Angioimmunoblastic T-cell lymphoma. (A) and (B). Blood films. Presence of large and small plasmacytoid lymphocytes and lymphoblasts and increased eosinophils.