Two dogs presented with nodular masses on the head and scapula. The masses recurred after excision and were submitted for histopathological examination. Macroscopically, hemorrhage and necrosis were apparent on the cut surface. Microscopically, the lesions were poorly demarcated and incorporated subcutaneous fat and adjacent skeletal muscle fibers. Fibrocytes and fibroblasts were admixed and haphazardly arranged. Both were diagnosed with nodular fasciitis (NF). NF has been rarely reported and called as a ‘pseudosarcomatous’ lesion because of its infiltrative growth and cellular pleomorphism. The present report describes unusual cases of recurrent NF in two young dogs based on histopathologic and clinical features.

Royal jelly (RJ) is one of the most attractive functional foods that have been a commercial product, especially in dietetics and cosmetics in many countries. However, RJ has been evoked with dermatitis, acute asthma and anaphylaxis because of major RJ proteins. Therefore, to access water soluble royal jelly (WSRJ) that removed allergy-induced proteins as an effective whitening agent for cosmetics and potential external treatment for topical use, we investigated its ability to inhibit melanin biosynthesis. B16F1 cells were treated with 10 nM α-melanocyte-stimulating hormone (α -MSH) for 48hr, and then were treated with various doses of WSRJ for 36hr. WSRJ (1-10ug/ml) inhibited direct tyrosinase activity and cellular tyrosinase activity, which lead to the decrease of melanin synthesis in α-MSH stimulated B16F1 melanoma cells. In addition, we examined RT-PCR and Western blotting for melanogenesis-related genes such as tyrosinase, tyrosinase related protein 1 (TRP-1) and 2. WSRJ suppressed mRNA and protein expression of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 in α-MSH stimulated B16F1 cells, and similar to positive control, arbutin. Our findings suggest that WSRJ induced the downregulation of melanogenesis by inhibiting tyrosinase, TRP-1 and 2 activations. It may serve as a new candidate in the new skin-whitening agents.