Granuloma Caused by Carbon Deposition in the Dermis

Pencil core granuloma is characterized by a delayed foreign-body reaction against retained fragments of pencil lead. Previous case reports presented pencil core granuloma resembling malignant melanoma, haemangioma, or soft tissue sarcoma. We present a case of pencil core granuloma arising from the palm 25 years after the initial injury. The patient presented a bluish nodule that had been present over 25 years before. The nodule initially measured 5？mm in diameter. However, five years before presentation, it suddenly enlarged to the size of 30？mm during six months. Computed tomography (CT) of the lesion revealed a linear radiopaque structure of 8？mm long with a mass on its distal end. Surgical resection revealed a bluish muddy mass and pencil lead. Histological examination revealed degenerative tissue with calcification surrounded by massive amounts of black granular material in the middle and lower dermis. Pencil core granuloma is characterized by a delayed foreign-body reaction against retained fragments of pencil lead. Previous case reports presented pencil core granuloma resembling malignant melanoma, haemangioma, or soft tissue sarcoma. We present a case of pencil core granuloma arising from the palm 25 years after the initial injury. The granuloma contained a pencil lead of 8？mm long without obvious breakdown. A 67-year-old woman was referred to our department for evaluation of a bluish nodule on the palm of her right hand (Figure 1, arrow). The nodule had been present for 25 years, initially measuring 5？mm in diameter. However, five years before her presentation, it suddenly enlarged to the size of 30？mm during six months. Then, the tumor ceased its rapid growth and its size remained unchanged thereafter. The tumor was solid and hard, measuring 30？mm in diameter. The rest of the findings of her physical examination were unremarkable. Computed tomography (CT) of the lesion revealed a linear radiopaque structure of 8？mm long with a mass on its distal end (Figure 2, arrow). The total excision of the tumor was performed, revealing a bluish muddy mass that contained a piece of material that resembled pencil lead (Figure 3). Histological examination revealed degenerative tissue with calcification surrounded by massive amounts of black granular material in the middle and lower dermis. Histiocytes laden with fragments of black graphite were also observed at the peripheral of the degenerative tissue (Figure 4). Figure 1: A bluish tumor of 30？mm in diameter was observed on the palm of her right hand. Figure 2: Contrast-enhanced CT showing a linear