Blood and lymph node T lymphocytes in cutaneous T cell lymphoma: evaluation by light microscopy.

Cytology of peripheral blood and lymph node lymphocytes from a group of unselected patients with cutaneous T cell lymphoma (CTCL) was studied by light microscopy. Twenty of 45 patients had circulating lymphocytes with convoluted nuclei recognized in routine Wright-Giemsa-stained peripheral blood smears. Cytocentrifuge preparations of E-rosetted lymphocytes showed that greater than 10% of the T cells had convoluted nuclei in each of 16 patients with positive blood smears and in six of 17 whose blood smears were negative or inconclusive. Peripheral blood involvement with greater than 10% convoluted T cells was most frequent in patients with erythroderma (100%) including those with normal of decreased lymphocyte counts, and was not uncommon in patients with mycosis fungoides in the plaque or tumor phase (42%). The light-microscopic morphology of the abnormal cells found in the patients with the plaque or tumor phase of mycosis fungoides was not distinguishable from that of the erythrodermic patients. Increased percentages (less than 15%) of T cells having convoluted nuclei were also found in the lymph node cell suspensions from CTCL patients with adenopathy (18 of 25 patients). These results suggest that a high frequency of extracutaneous involvement occurs in patient with CTCL, the clinical significance of which remains to be determined.