Sweet syndrome and erythema nodosum in a case of anal canal cancer during concomitant radiochemotherapy

539 triphosphate, the accumulation of which is cytotoxic and can lead to lymphocyte death in both the mitotic and resting phases. Cladribine has shown to be relatively effective for the treatment of haematological cancers and has also been proven to be effective in treating other histiocytosis [8]. It is used to treat refractory Langerhans cell histiocytosis, and long-term remission has been achieved with tolerable side effects [9]. Khezri et al. [1] have reported five cases of XD treated with cladribine; two cases reached complete clearance, with no relapse after three to eight years of follow-up. Gupta [2] and Adışen et al. [3] also reported a case of XD effectively treated with cladribine. All of our three patients had significant improvement after treatment and have been in remission since. However, in our cases, similar to the cases in other reports, there was no significant improvement in symptoms of anosmia or diabetes insipidus, both of which are considered to be irreversible complications associated with XD. None of our patients suffered from bone marrow suppression, the major adverse effect of cladribine, suggesting that this treatment regimen is safe to use in adults and, more importantly, children. Reports in recent years, including our three cases, have shown that cladribine is safe and effective in treating XD. Although the underlying mechanism of cladribine remains unclear, we propose a treatment algorithm for XD based on current knowledge and experience (supplementary table 1).