The cause of the disease is still unclear. Some researchers showed that patients with familial adenomatous polyposis(FAP) have a higher risk of developing desmoid-type fibromatosis, comparing with non-FAP population .Meanwhile, FAP related tumors are more likely to occur in the abdominal cavity.Other studies suggest that surgical trauma and neuroendocrinology may have an important role in the pathogenesis of DF[8, 9].Although the cause of DF remains controversy , most of them acknowledge that the pathogenesis should be a combination of multiple factors.
Mutations in the CTNNB1 gene, which encodes beta- catenin, are considered to be the key factor of pathogenesis in sporadic DF. CTTNB1 is located on chromsone 3p21 with 16 exons, which mainly encode beta-catenin. The mutation in the CTNNB1 gene that result in elevated beta-catenin appear to alter mesenchymal stem cell differentiation , and remarkably promoting the growth of tumour. Beta-catenin is a transcriptional activator which significantly associated with a potential risk of recurrence.In the case of CTTNB1 mutation, the incidence of DF can be significantly increased, from 39% to 87%.Therefore, mutation analysis of beta-catenin is regarded as a specific diagnostic tool for DF diagnosis.
The preoperative diagnosis of desmoid-type fibromatosis is challenging. With no specificity on imaging, intra-abdominal DF is often confused with other soft tissue tumor, especially gastrointestinal stromal tumors (GISTs). Up to now, magnetic resonance imaging (MRI) is still the main means of imaging, which can be used for diagnosis, local staging and follow-up.Although the key diagnostic feature in MRI has already pointed out for decades,influenced by the experience of clinicians ,the misdiagnosis rate is still high in the preoperative diagnosis of DF. Imaging is helpful to determine the location and invasion of DF, but it can hardly distinguish it from other soft tissue tumors. Meanwhile, due to the complexity of organizational structure, determining the origin of tumor by imaging means is also difficult. Hence, comparing with the diagnostic value, imaging may be more advantageous in management of the disease, especially when tumors occur in rare locations.
Pathologic examination is the primary means of diagnosis. However, nuclear accumulation of beta-catenin has been also observed in other soft tissue neoplasms. In this case, a mutations analysis of CTNNB1 should be performed，which is more specific to the diagnostic of DF. Even DF is a rare disease, due to the high rate of recurrence, European Organization for Research and Treatment of Cancer (EORTC) suggested that needle biopsy should be mandatory prior before the treatment is started.The accurate preoperative diagnosis of DF is still challenging, and a complete diagnostic strategy seems necessary. Recent research has been working toward this aspect. A study comes from Poland presented a short algorithm(Fig 3.) of immunostainings that can be useful in differential diagnosis.
The treatment of DF has changed in the past 10 years. Up to now. There is no standard treatment for DF. Therapeutic options include surgical resection, radiation therapy, chemotherapy, anti-inflammatory therapy, and hormone therapy.
Therapy is necessary when the disease causes obvious symptoms, if possible, surgical resection is still the first choice of treatment. According to the guide line of Nation Comprehensive Cancer Network (NCCN), surgical resection should be considered for patients with clinical symptoms or organ dysfunction.But recently, there is a current shift to non-surgical approaches, named the “wait-and-see policy”, due to the high risk of relapse after surgery. Even if it is still controversial, more and more investigators have recommended that the “wait-and-see policy” has been proposed and advocated as a viable approach to therapy.This approach has been assessed by many different trails .A study from France comparing surgical versus “wait-and-see policy”,which conducted a prospective study of 771 confirmed cases, found that these was no significant difference in prognosis between the two groups .The studies also pointed out that the position of DF can affect prognosis, especially in the abdominal wall, abdominal cavity ,breast, digestive organ and lower limbs.A meta-analysis with a large sample size yielded similar results. Therefore, compared with other disease, the surgical treatment of DF should be chosen with caution, a personalized treatment strategies are necessary according to the changing consensus.
Radiation and systemic therapy are recommended for patients with unresectable or recurrent disease. Some researchers suggested that radiation therapy cannot reduce the risk of local recurrence after surgery, especially for patients with an initial negative margin. Meanwhile, other researchers had found positive effects for those who suffered multiple operations or progressive disease.Thus, radiation therapy is regarded as an adjuvant therapy for incomplete resection or recurrence. For such patients, a systemic therapy also could be helpful. While there are many options, including chemotherapy, hormone therapy, target therapy and anti-inflammatory therapy, the therapeutic effect are generally poor. Further research of drugs are still needed.
According to the above consensus, there were some different that should be pointed out in our treatment process. Although it is recommended for both NCCN and EORTC, we did not have a needle biopsy before the surgery. Why? Our MRI scan incorrectly revealed a complex mass in the liver, which could be a stromal tumor, a hemangioma or something else. In this case, a needle biopsy may cause significant bleeding, breaking or metastasis. At the same time, these complications will be more danger while occurred in the abdominal cavity. On the other sides, making a definitive diagnosis for using a fine needle aspirate sometimes seems to be difficult, especially for the intra-abdominal mass. Regardless of the result, in this case, it may lead to obvious disputes due to different cultures in the East and the West. Different from DF in other position, in case of no accurate pathological diagnosis before operation, a “wait-and-see policy” seems be not appropriate. In that way, for Chinese patients with intra-abdominal DF, the treatment seems to be contradictory when following the consensus. On the other hand, it may also cause more risks for clinicians.
Intra-abdominal DF is often confused with gastrointestinal stromal tumors, meanwhile, the two diseases are similar in tumor behavior. Besides, some researchers suggested that DF may be controlled by the same genes in the process of the disease with GISTs[23, 24]. But what`s interesting is that the incidence and treatment cases of GISTs is higher than DF. Thus, for this rare disease, is it a feasible method to treat DF according to the experience of GISTs by surgery treatment? ( According to the NCCN`s guideline of GISTs, surgery treatment is the first choice treatment ).There is some moderate evidence suggest surgery may be more helpful for those patients who are suitable for complete resection, considering of difficult preoperative diagnosis. The association of two disease may need further studies to elucidate. Besides, a complete surgical exploration before remove it for this rare disease is always necessary. The clinicals should keep a rigorous attitude, especially when preoperative diagnosis is difficult. In the case of misdiagnosis, this maybe the reason why the operation is effective for this patient. Also, for further understanding of DF, we have a simple summary of the three kinds of diagnosis in this case (Table.1).