RESUMEN
BACKGROUND: The frequency of nail unit tumors is not well known because they are often misdiagnosed, and the clinical appearance of benign and malignant tumors is not characteristic. PATIENTS AND METHODS: A total of 234 patients from the dermatology department of a general hospital in Mexico City were included in this study, from January 1982 to November 2006. RESULTS: The tumors most frequently diagnosed were fibrous tumors (29.05%), osteocartilaginous tumors (21.79%), and myxoid pseudocysts (11.96%). Malignant melanoma occupied the fourth place (9.82%), and the second most frequent malignant tumor was squamous cell carcinoma (SCC; 4.70%). Among other tumors were glomus, neurofibromas, giant cell tumors of tendon sheath, and pyogenic granulomas. The nail plate was affected in 46.5% of the cases studied. CONCLUSION: This study in a Mexican population sheds light on the frequency and the alterations produced by nail unit tumors, which we must keep in mind for a more accurate diagnosis.