Abstract

An analysis of 6 cases of subungual exoatosis which were examined in depatment of path- ology, during the period from 1980 to August, 1983, was done. All tumors occurred in patiente who were in the second decade of life. The mean age of patients at the time of diagnosis was 16.4 years(range, fifteen to eighteen years). The tumors were commoner in females in the present series in the ratio of 3 : 2. Four of the tumora occurred on the left great toe, one on the right second toe. History of major trauma was noted in two cases. Histologically, the tumor cansists of a proliferating fibrocartilaginous cap that was merging into matwe trabecular bone at its base. T4e growth in the cap was so active that it sometimes mimicked carcinoma, But no true anaplasia was seen. No recurrence was noted in all the cases after local excision of the mass. The subungual exostosis seems to represent cartilaginoua metapla- sia occurring in response to acute or chronic irritation.