Primary cutaneous marginal zone lymphoma with unusual histopathological features: Subcutaneous involvement and epidermotropism with massive fibrosis

Abstract

therapy. Pathophysiology of nail changes in atopic dermatitis is currently unknown. Nail matrix and nail bed could be affected in the same way as the skin. Our patient’s nail abnormalities did not improve neither with methotrexate or TNF-alpha inhibitors, which are mainly Th1-mediated lymphocytic response inhibitors, nor with cyclosporine, a non-selective lymphocytic inhibitor. The relevant improvement in nail manifestations of our patient after treatment with dupilumab, a specific Th2 pathway blocker, could indicate the presence of an inflammatory infiltrate at the nail matrix or the nail bed formed predominantly by Th2 lymphocytes, similar to what we currently know in atopic eczema. Moreover, it does not seem that the polarisation of na€ıve T lymphocytes to Th1 and Th17 after treatment with Th2 inhibitors can trigger psoriatic onychopathy in patients with atopic dermatitis; however, future observations and studies will be necessary to know this detail with a greater accuracy. Dupilumab can improve nail manifestations associated with atopic dermatitis, may be acting in a similar way to that observed on the skin. Clinical response to treatment can be observed throughout the first 3 months of therapy. In those cases who do not respond clinically during the first months, we think it would be advisable to wait at least for 6 months to consider onychopathy is not responding, after a cycle of nail growth has been completed.