Granular cell tumor of the neck treated using a local flap: A case report

Rationale: Granular cell tumors are rare soft tissue neoplasms derived from nerve that can arise in the oral cavity, skin, or gastrointestinal tract. Various hypotheses have proposed that granular cell tumors originate from the nervous system, skeletal muscle, and Schwann cells. Patient concerns: A 47-year-old male patient presented with a 5 cm cervical mass. Diagnoses: Computed tomography showed a 4 cm-sized homogeneous enhancing mass infiltrating the sternocleidomastoid muscle and even the surrounding skin. Interventions: Extensive surgical resection of the tumor including the skin was performed. A submental transposition local flap was used for the wide skin defect. Outcomes: Histologic finding showed polygonal granular cells with rich eosinophilic coarse granular cytoplasm without interstitial tissue without mitosis or necrosis. Immunohistochemically, the tumor cells were positive for S100 and CD68, which is consistent with classic granular cell tumors. Lessons: In microscopic observations, granular cell tumors do not have a defined boundary with surrounding tissues, and they display an infiltrating pattern that can expand to adjacent tissue. As a result, the tumor should be removed with a sufficient margin, including the normal tissues surrounding it. The authors experienced granular cell tumor in the muscle layer of the head and neck. It could be treated without recurrence through extensive surgical resection and local flap.