Spitz nevus with an uncertain malignant potential.

: We present the case of 10-year-old girl who have had from birth a plane tumor, of tan color, 3-4 mm of diameter, localized on the face on the cutaneous part of the superior lip. This tumor has been stabile until 8-year-old. Then, after repeated sunlight exposures, the lesion has become more stark, hemispheric in shape, has increased in size becoming about 5-6 mm, with irregular borders, and after an accidental traumatism it began to bleed. We have performed the electroexcision of the lesion for diagnostic and therapeutic purpose. The histopathologic exam distinguished typical images of Spitz nevus on some of the histological sections but also of melanocytary tumor with uncertain malignant potential on the others where atypical mitoses localized in the deeper component of the tumor are being noticed. The immunohistochemical assessment of the tumoral cells showed positivity for the melanocytic markers HMB45 and Melan A, within junctional intraepidermic nevic cells and in the nevic cells from superficial dermis, and also for CD44 protein (belonging to the adhesion molecules family). However, cyclin D1 was positive in rare nevic cells, and the proliferation rate of the tumor was small, with a proliferation index for Ki67 lesser than 5%. The correlation between histopathological and immunohistochemical data conducive to final diagnosis of Spitz nevus with uncertain malignant potential. The clinical evolution confirmed the histopathological diagnosis by the fact that the patient did not presented clinical signs of local recurrences or metastasis at three years after the excision of the tumor.