Intended for in vitro diagnostic (IVD) use. Anti-Factor XIIIa is useful in differentiating between dermatofibroma, dermatofibrosarcoma protuberans, and desmoplastic malignant melanoma. Positivity is also seen in capillary hemangioblastoma, hemangioendothelioma, hemangiopericytoma, xanthogranuloma, xanthoma, hepatocellular carcinoma, glomus tumor, and meningioma. Reference 1. Abenoza P, et al. CD34 and factor XIIIa in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans. Am J Dermatopathol. 1993; 15:429-34 2. Horenstein MG, et al. Indeterminate fibrohistiocytic lesions of the skin: is there a spectrum between dermatofibroma and dermatofibrosarcoma protuberans? Am J Surg Pathol. 2000; 24:996-1003 3. Kraus MD et al. “Juvenile” xanthogranuloma: an immunophenotypic study with a reappraisal of histogenesis. Am J Dermatopathol. 2001; 23:104-11.