<s>[INST] context: Desmoid tumors, also known as "aggressive fibromatosis," are soft tissue lesions that behave similarly to other truncal soft tissue sarcomas but have unique characteristics. These tumors, like other soft tissue sarcomas, present as slow-growing, indolent masses (sometimes can be aggressive). Unlike typical sarcomas however, these tumors rarely metastasize.
Desmoids are diffusely infiltrative and tend to recur locally, even after complete resection..
Most desmoid tumors arise sporadically, but a small percentage (-5%) occurs in association with FAP syndrome.
Desmoids are classified as either abdominal or extra-abdominal. Abdominal desmoids are categorized further as superficial or infra-abdominal tumors . The superficial disease, also known as Dupuytren's fibromatosis, is slow growing, is small in size, and rarely involves deeper structures.Most of the intra-abdominal lesions are seen in association with FAP. These lesions are associated with mutations in the APC gene that are found in patients who have FAP. These tumors usually are found in the mesentery, and their growth and compression of neighboring structures can lead to significant morbidity and sometimes even death in these patients
Sporadic abdominal wall desmoid tumors have been found to be associated with pregnancy. Oral contraceptive use has also been associated with the occurrence of these tumors. These associations, combined with the detection of estrogen receptors within the tumor, suggest a regulatory role for estrogen in this disease.
Tissue injury, such as trauma and/or surgery, also has been implicated in tumor development.
The natural history of desmoid lesions is unpredictable. Although most are indolent and slow growing, some lesions are aggressive. There are some reports of spontaneous regression, but such occurrences are mainly in women and are associated with chemical or surgical menopause. Most lesions are indolent and have benign-appearing histology, but local growth and compression have caused significant morbidity. Involvement of abdominal vessels and organs often complicates management.
Patients with desmoid tumors present with a painless enlarging mass. Local symptoms may arise from compression of adjacent organs or neurovascular structures.
MRI is done to define the extent of disease and its relationship with other structures.
Incisional biopsy or a core needle biopsy is done to confirm the diagnosis.


Management: 

Surgery with wide negative margins is the best treatment. Unfortunately, even with complete resection, the local recurrence rate is as high as 40%. Surgery is also the t/t of choice for recurrences.
For tumors where vital visceral organs and local infiltration often make achieving negative margins difficult, other therapeutic modalities have been suggested.


Antiproliferative agents and cytotoxic chemotherapy have been used to palliate these tumors with variable results. The two most widely used groups of noncytotoxic drugs are NSAIDs (such as sulindac and indomethacin) and antiestrogens(such as tamoxifen).
Chemotherapy has generally been reserved for unresectable, symptomatic, and clinically aggressive disease. Partial responses have been observed after treatment with doxorubicin, actinomycin C, dacarbazine, or carboplatin, although toxicity has been relatively high.
Radiotherapy-"The role of radiation therapy in the management of these tumors, either as an adjunct to surgery or as primary treatment, continues to be defined." — Sabiston


"In summary, for easily resectable disease, surgery alone appears to be the optimal approach, especially in patients with negative microscopic margins. In advanced cases, a trial of nonsteroidal anti-inflammatory drugs or hormonal therapy can be considered in most patients. A period of close observation is also reasonable because some patients demonstrate regression without any therapy. However, if a patient is symptomatic and not a candidate for surgery, consideration should be given to radiation or chemotherapy to increase the chance of a response."-Devita Oncology [/INST] question: Desmoid tumor, treatment is: | options: A: Local excision B: Wide excision C: Wide excision with radiotherapy D: Radiotherapy | answer: B </s>