A Case of Graphite Foreign Body Misdiagnosed: DISCUSSION
In childhood, there can be many accidental traumas by pencils while playing with friends. In most cases, children are afraid of being blamed for the accidents by their parents, so they usually do not notify an adult and leave the wounds as they are. If these pencil lead wounds are left as they are, the lead would remain, possibly resulting in undesirable local pain, pigmentation, graphite foreign body reaction, and abscess formation. Wounds should carefully be inspected by a school nurse or a medical doctor at the time of the accidental trauma.
Injuries caused by pencils are common and usually trivial. A pencil is a writing or drawing instrument consisting of a thin stick of lead, usually encased in a thin wood cylinder. The lead of a pencil is composed of graphite (elementary carbon), clay (aluminium silicate), various waxes, and lacquers. Among them, graphite and clay are the main components. Microanalysis of the lead of a pencil reveals that it is composed of 72.2% carbon, 19.0% oxygen, 5.0% silicon, 3.5% aluminum, and 0.3% magnesium. canadian pharmacy viagra
Although the lead of a pencil is generally known to induce a non-allergic granulomatous reaction, each of the components could induce a tissue reaction. Silica, a component in clay, can incite an epithelioid granulomatous reaction. Graphite particles may cause a chronic granulomatous reaction in the lung called graphite pneumoconiosis and rarely, graphite foreign body granuloma. Graphite foreign body granuloma(pencil core granuloma) is characterized by a delayed foreign body reaction against the remaining fragments of pencil lead and at the macroscopic level, it resembles malignant melanoma. The occurrence of pencil core granulomas is rare, only a few case reports have been documented in literature. Pencil core granulomas as well as silica granulomas appear to have delayed reactions, with lag periods of 1.5-58 years between injury and granuloma formation. This time lag seems to be the time required for the breakdown of graphite to a critical size as well as dispersal to the interstitium. The mechanism for the formation of this type of granuloma is not clear, but we speculate as follows. The dispersal of graphite particles causes an accumulation of macrophages, and the accumulated macrophages then release various cytokines and growth factors that induce the proliferation of fibroblasts. Finally, ischemia caused by ectatic changes in the blood vessels in the lesion induces tissue fibrosis.
