Desmoid tumor, also called deep-seated fibromatosis, is a benign tumor that is nonetheless a nasty beast. It is composed of fibroblasts, and it often presents as a large, infiltrative masses. Desmoid tumors may occur in patients with familial adenomatous polyposis (also called Gardner syndrome), an autosomal dominant disorder characterized by innumerable colon polyps (hence the name), as well as other lesions such as osteomas, jaw osteomas, odontomas, thyroid carcinoma, epidermoid cysts, fibromas, and sebaceous cysts. If the colon is not removed in a patient with familial adenomatous polyposis, the chance of colon carcinoma is virtually 100%.
Back to desmoid tumors. These tumors usually present as firm, rubbery, ill-defined, infiltrative masses. They may occur in extra-abdominal regions (for example, in the shoulder or thigh), within the abdominal wall itself (often attached to the rectus abdominus), or in the intra-abdominal region. Histologically, desmoid tumors are composed of bland-appearing fibroblasts in broad fascicles that infiltrate surrounding tissue. Check out the photo above: you can see muscle fibers being splayed apart by benign-looking, round-to-spindly tumor cells.
Although benign, desmoid tumors can act nasty. They are locally aggressive and invasive, and if you don’t excise them completely, they are likely to recur. Currently, the drugs that are being used to treat desmoids include cyclooxygenase 2 inhibitors, tyrosine kinase inhibitors (such as Sorafenib) and hormonal blockade drugs (such as tamoxifen).
My husband had a messenteric Desmoid resected from duodenum this Summer and I agree with all of this until the end….Desmoids do not respond well to chemo, tamoxifen or any drugs/modalities usually employed for malignancies known to metastasize. The best promise to date, is excision, surveillance and Sorafenib.
Thanks, Alexandra. I’m sorry to hear about your husband’s tumor. Thank you for sharing the treatment information. Our best pathology reference, a book called Robbins Pathologic Basis of Disease, just came out with a new edition, and in the section on desmoid tumors, the new edition now states that recent medical treatment efforts have centered on cyclooxygenase 2 inhibitors, tyrosine kinase inhibitors (which is the category of drugs Sorafenib belongs to), and hormonal blockade (such as tamoxifen). The old edition stated that tamoxifen, chemotherapy and radiation were effective. I’ve changed the last part of this post to reflect this update. Thanks again for sharing that with us! My best to you and your husband.
I would have to disagree with Alexandra’s statement on chemo. My son did weekly treatments of methotrexate and vinblastine and had 50% shrinkage in 7 months. His desmoid is in his calf and was non-resectable at diagnosis. I was told by Dr. Maki, a well recognized expert in desmoids, that each tumor is different and responds differently. The trick is to find what works for your tumor and go with it. For us, chemo was successful.
From which cell does desmoid tumor arises ? Is it fibroblast ?