[Pilomatrix carcinoma--report of the second case in Japan and a review of the literature].

A 53-year-old man had a rapidly growing tumor, measured 3 cm in diameter, on his left temporal region of 2 months' duration. The lesion showed histological resemblance to pilomatricoma but differed by the presence of irregular nests of atypical basophilic cells (basaloid cells) with focal squamoid differentiation and a large number of atypical mitoses. A review of 16 cases of pilomatrix carcinoma documented since the year of 1980 indicated that this tumor occurs in males three times more frequently than in females. 75% of all patients were over forty years old. Recurrences were seen in 6 of the 10 patients whose tumor had been resected simply, but there was no evidence of recurrence in the 4 patients with a wide resection of tumor.