Occult Dermal Lymphatic Involvement Is Frequent in Primary Cutaneous Anaplastic Large Cell Lymphoma

Primary cutaneous anaplastic large cell lymphoma (pcALCL) is an indolent T-cell lymphoproliferative disorder managed with low-dose radiation therapy, surgery, and/or mild chemotherapy; patients with extensive limb disease (ELD) have a more aggressive clinical course. We have previously demonstrated that histologically apparent vascular involvement in pcALCL is lymphatic. We hypothesized that histologically occult lymphatic involvement may be associated with particular patterns of disease spread that could involve lymphangitic spread including locoregional spread of disease in the form of ELD and extracutaneous spread of disease. We have therefore set out to quantitate the incidence of occult lymphovascular involvement in pcALCL and to assess for an association between lymphovascular involvement and these patterns of disease. We performed immunohistochemistry for the lymphovascular marker D2-40 on skin biopsies from 29 patients with pcALCL followed in the Stanford Cutaneous Lymphoma Clinic. Immunohistochemically evident dermal lymphovascular involvement was found in nearly half of cases examined (48%; 95% confidence interval, 29%-67%). There was a nonsignificant trend toward a higher prevalence of ELD among patients with pcALCL involving dermal lymphatics (7% vs. 29%; p = 0.12). In this small cohort, there was no indication of a significantly more aggressive disease course in patients with lymphatic involvement either in the form of disease-related mortality (one each in the lymphatic and nonlymphatic groups) or in time to extracutaneous involvement.