Extra-Abdominal Fibromatosis (Desmoid Tumor)

Fibromatoses are a group of benign fibroblastic proliferations with an infiltrative growth pattern and whose histologic features and biologic behavior are intermediate between benign fibroblastic lesions and fibrosarcoma. They tend to recur but never metastasize. Grossly, they have a whitish, firm, whorled cut surface. Courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com.