A Case of Trichoblastic Fibroma at the Cheek

PURPOSE: Trichoblastic fibroma originates from hair germ layer tumor which is a benign tumor mixture of epidermal and mesodermal factor. Trichoblastic fibroma was found only in adults and showed equal occurrence rate between men and women. Since it is a rare tumor, we report a case of a trichoblastic fibroma which developed on the right cheek. METHODS: A 72 year-old male was treated with excisional operation 17 years ago due to a solitary tumor that developed on the same site. He returned to the hospital with an asymptomatic mass which have been increasing in size for the last 3 months. RESULTS: In computerized tomography, a size of 2.7 x 2.3 x 0.8cm tumor was found in the subcutaneous tissue layer. Grossly, the mass was well-circumscribed, smooth-surfaced and flesh colored, and was lobulated and fragile. Pathologic observation showed diverse shaped and sized tumor cell nests and fibrocellular stroma consisting basophilic cells in dermal and subdermal layers. Immunohistopathologic staining showed positive reaction on pancytokeratin, CK-5/6, and bcl-2. CONCLUSION: By having no connection to the epidermis, and being positioned in the dermal and epidermal layers, typical pathologic findings make it possible to differentiate this tumor with basal cell carcinoma. This lesion is not clear whether it is a local recurrence or not, and it is necessary to observe a new recurrence in the future.

Valproic Acid Effect in Nerve Regeneration Using Gore-Tex(R) Tube Filled with Skeletal Muscle

As the large defect of peripheral nerve occurs, the autologous nerve graft is the most ideal method but it has many limitations due to donor site morbidities. Various materials have been developed for the nerve defect as the conduits, but none of these materials is satisfactory. Among them, Gore-Tex(R) tube seems to be one of the most ideal nerve conduit materials at peripheral nerve defect. Many researches have focused on finding the neurotrophic factors. It is recently demonstrated that Valproic acid(VPA) has an effect of axonal regeneration as a neurotrophic factor without enzymatic degradation and toxicity problems. The purpose of this study is to evaluate the effect of VPA on the nerve regeneration at the peripheral nerve defect. A 10 mm gap of rat sciatic nerve was made and Gore-Tex(R) tube filled with biceps femoris muscle was placed at the nerve defect site. We let the rat take VPA as drinking water in experimental group and did not give VPA to the control group. We estimated the results as electrophysiologic and histological aspects for 16 weeks after the surgery. The nerve conduction velocity, total myelinated axon count, myelin sheath thickness and mean nerve fiber diameter significantly increased in VPA-treated experimental group when compared to the control (p < 0.05). From the above results, we conclude that VPA promotes the nerve regeneration at the peripheral nerve defect site. It is suggested that Gore-Tex(R) tube filled with skeletal muscle and VPA administration may be a good substitute for autologous nerve graft.