Pilomatrixoma : Histology
Basaloid cells of pilomatrixoma are uniform and have scant cytoplasm, round vesicular nuclei and prominent nucleoli. Mitotic activity is high, but abnormal forms are not seen. Pilomatrixoma in elderly patient may show atypical features, including nuclear hyperchromasia and pleomorphism, loss of polarity, and atypical mitotic figures. Lymphovascular invasion or perineural invasion are not seen. The clinical behavior is the same as conventional pilomatrixomas seen in the younger age group. However, these tumors should be completely excised (negative margins) and closely followed for recurrences.