[Cutaneous granular cell tumor: a clinical and pathologic analysis of 34 cases]

Granular cell tumor (GCT), also known as Abrikossoff tumor, is an uncommon benign neoplasm, probably of neural origin derived from Schwann cells. It presents clinically as a solitary asymptomatic nodule and its pathogenesis has been the subject of much debate in the literature.

We aimed to analyze the clinical, histologic, and immunohistochemical characteristics associated with this tumor and to determine whether these findings correspond to those reported to date in the literature.

In this retrospective study of 34 patients with histologic diagnosis of GCT, we analyzed clinical characteristics (site, age, sex, duration, and suspected diagnosis), histological findings (border, cell atypia and mitoses, involvement of adnexal structures, pseudoepitheliomatous hyperplasia, and presence of the recently described pustulo-ovoid bodies), and immunohistochemical findings (S-100 staining in 16 randomly selected cases).

In total, 58.82 % were men and 41.18 % were women, and the mean age was 31.74 years. The most common site was the oral cavity (61.76 %). The most frequently suspected clinical diagnosis was fibroma (17.65 %). The lesion was poorly defined and diffuse in 85.29 %. Pseudoepitheliomatous hyperplasia was present in 58.82 %. Nuclear atypia was found in 29.41 % and mitoses in 20.59 %. One case was considered malignant (2.94 %) and 2 atypical (5.88 %). Pustulo-ovoid bodies were present in 47.06 % of the cases and S-100 staining was positive in all cases analyzed.

Our series confirms the characteristics described previously for GCT, except for certain peculiarities, and supports the presence of pustulo-ovoid bodies as an additional histologic finding for diagnosis of this tumor.