Sections demonstrate unremarkable epidermis with a nodular dense dermal atypical lymphohistiocytic infiltrate comprising small, medium-sized and occasional large lymphoid cells admixed with histiocytes, plasma cells and rare eosinophils.

The lesion contains numerous T-cells on CD3 immunostain. However, CD20 immunostain also highlights a fair number of small B cells. The excess of background small B cells is frequently seen in this lymphoproliferative disorder compared to other  T cell lymphoproliferative processes.

There is marked excess of CD4 T cells compared to CD8 T cells.

CD5 and CD7 immunostains show markedly fewer numbers of CD7 positive T cells. Both of these markers are pan T-cell antigens and based on visual estimation, there should be equal numbers of CD3, CD5 and CD7 positive lymphoid cells on immunohistochemistry.

CD30 immunostain highlights singly scattered rare immunoblasts and T-cell receptor beta immunostain demonstrates numerous cells maturing in numbers with CD3 and CD5 consistent with expression of T-cell receptor beta on T-cells within the infiltrate.