A Rare Case of Cutaneous Granular Cell Tumor Misdiagnosed as Sebaceuos Cyst

Abstract

Granular cell tumor (GCT) is a rare benign skin tumor. The tumor mostly presents with a symptomatic slowly growing solitary nodule and no overlying skin changes; therefore, it is not always considered in the differential diagnosis. We report a case of cutaneous GCT in the right supra-scapular region in a 43-year-old middle eastern female, who presented with a 2-year history of a slowly growing mass, with a dimension of 3 × 2 cm, initially misdiagnosed as a sebaceous cyst and later diagnosed as a GCT at the histopathological examination, followed by second excision with wide margins. The tumor cells had centrally located nuclei and granular eosinophilic cytoplasm and stained positively for S100 and CD68 antibodies on immunohistochemistry. Even though GCTs are rare, they should be thought of when diagnosing soft tissue tumors under the skin. Malignant changes have been reported in cases after long term follow-up, so surgical removal with wide margins is considered the best line of management.