(P58) Multiple Recurrences of Granular Cell Tumor in the Skin: A Case Report and Review of the Literature

Abstract

Granular cell tumors are rare tumors of Schwann cell origin. Rapid growth, aggressiveness, and histological markers characterize these tumors. Granular cell tumors (GCTs) are very uncommon (0.5% of all soft tissue tumors) and malignant granular cell tumors are even rarer. We present the clinical, pathologic, and radiographic features of a submental granular cell tumor of the skin that recurred multiple times in a 51-year-old African American man. The patient was a 51-year-old male who presented with swelling underneath his chin. He had a history of “keloids”; treatment included multiple surgeries and short-course radiotherapy. Eventually, an excisional biopsy was completed, showing granular cell tumor with positive margins. He was treated at our institution to 66Gy in 33 fractions via IMRT to the surgical bed with a treatment margin. The patient did well with treatment with minimal toxicity and had no evidence of disease for 10 months. Unfortunately, he developed new soft-tissue nodules in the surgical bed and radiation treatment field. On biopsy, recurrent granular cell tumor was confirmed. Given the complexity of his case, he was referred to an oncologic otolaryngologist for further evaluation and treatment. He was recommended surgery but on preoperative evaluation, he was noted to have lung metastases; he was started on chemotherapy. Discussion: Surgical excision has been the primary treatment strategy used in the treatment of GCTs. However, the prognosis remains poor, particularly with malignant granular cell tumor where > 50% of patients develop metastases. Given our patient’s multiple local recurrences and positive margins, we felt adjuvant radiotherapy was a reasonable treatment option for him to maximize local control. Radiation therapy was intended to decrease locoregional failure. There is not much published literature on the role of radiotherapy for GCTs. Case reports where adjuvant radiotherapy was used have demonstrated good disease control. Granular cell tumors are rare tumors that sometimes present in the soft tissues of the head and neck. Based on the existing literature, adding adjuvant radiotherapy after surgical resection in high risk patients is a reasonable treatment approach. Our case report highlights that these tumors can recur locally multiple times and demonstrates the importance of proper upfront diagnosis and management. Local treatment with surgical excision and radiation is a reasonable treatment approach.