Background: Incidence of amelanotic subungual malignancies is small, but they are not extremely rare and are often omitted in the diagnostic algorithm of subungual lesions.
Methods: Retrospective analysis of four amelanotic subungual tumours--2 subungual melanomas and 2 spinocellular carcinomas. Diagnosis was made by surgeon and pathologist.
Results: We have observed frequent traumatic history, patients' symptomatology underrating, inconspicuous clinical manifestation with unusual macroscopic morphological features and a risk of diagnostic delay.
Conclusion: It is necessary to consider possibility of subungual malignancies in diagnostic algorithm of nail unit pathologies. Early diagnosis enables the reduction of amputation rate. We recommend excision biopsy with low indication threshold. There is fatal risk of delayed diagnosis especially in subungual melanoma cases, and mostly mutilation risk in spinocellular carcinoma cases.