The objective of the present work was to present the results of the clinical analysis of the patient presenting with natural killer (NK)/T-cell lymphoma of the nasal type. We undertook the analysis of the medical documentation concerning the case of interest. It was shown that the development of progressive perforation of the nasal septum and the pronounced destructive changes in the intranasal and adjacent structures following the endonasal surgical interventions made necessary differential diagnostics between the condition under consideration and certain latent disorders (such as Wegener's granulomatosis, leprosy, syphilis, leishmaniasis, dirofilariasis tuberculosis, etc.). The study has demonstrated that the negative results of the analysis imply the necessity of special attention to the possibility of development of oncological diseases including hematological disorders (e.g. NK/T-cell lymphoma) and the repeat careful follow-up examination of the patients by the experienced experts.