Malignant granular cell tumor of the chest wall

Abstract

A 75-year-old Japanese male presented with a subcutaneous mass that developed from a small nodule over 1 year. Physical examination revealed a mass measuring 18 cm×15 cm in size in his left chest wall. Although biopsy specimens of the mass indicated a granular cell tumor (GCT), a diagnosis of malignant granular cell tumor (mGCT) was made based on the clinical course. The tumor was completely excised. Excised specimens in the shallow area were identified as GCTs ; on the other hand, those in the deep area were found to be mGCTs. During 4 years of follow-up, contrast-enhanced computed tomography revealed masses in his lungs and liver. Due to his age, palliative care was recommended. The origin of mGCTs is unclear. In our patient, mGCTs were accompanied by GCTs, suggesting transformation from a benign tumor to a malignant one. Further studies are required to elucidate the nature of mGCTs.[Skin Cancer (Japan) 2017 ; 32 : 61-65]