D. Granular cell tumor
Granular cell tumors are benign tumors of ubiquitous distribution. However, the tumor appears to occur more commonly in the head and neck area. The tumor has been described mainly in adults but it can occur in children as well. In many circumstances the tumor is found incidentally, while in other cases it may elicit symptomatology.
Immunohistochemical stains that may help in the diagnosis include S-100 protein, which is commonly positive in tumor cells.
In the past, the tumor was also called “myoblastoma” with the idea that the tumor originated from muscle cells, which has been shown not to be the case. Although the tumor may also show a malignant counterpart, that occurrence is rather unusual. Complete surgical resection is the treatment of choice for the conventional granular cell tumor.