Background: Granular cell tumor (GCT) is a rare, usually benign mesenchymal neoplasm of nerve sheath origin. Malignant GCTs are the rarest sarcomas and represent 2% of all cases of GCT. Distinction between benign and malignant GCT is often difficult because of histologic similarity, and the development of metastases represents the only definitive criterion for diagnosing malignancy. Cases: We report 3 cases of GCT that were diagnosed as malignant, atypical, and benign, respectively, as identified by clinicopathological data, immunohistochemistry, and Ki-67 cell count morphometric analysis. The case of malignant GCT was identified in a 61-year-old woman; it first appeared as a subcutaneous inguinal mass followed by recurrence and metastases. The second case was atypical GCT in a 47-year-old woman, presenting as a cutaneous nodule in her neck. Our third case was benign GCT in a 41-year-old woman in the scapular region. Immunohistochemistry was performed and the tumors were positive for vimentin, S-100 protein, CD68, and a-inhibin. The Ki-67 proliferation indexes were 9.62% in the primary, 10.21% in the recurrent, and 10.9% in the metastatic tumor in the malignant case; it was 5.06% in the atypical case and 1.8% in the benign case. Conclusion: Adequate histopathological evaluation with immunohistochemical analysis is crucial to avoiding errors in the diagnosis of GCT. Increased Ki-67 proliferative index might help classification of GCTs in difficult cases as one of the criteria for malignant GCT. © Science Printers and Publishers, Inc.