2 A mesh reconstruction was not necessary. Surprisingly, an aggressive musculoaponeurotic ﬁbromatosis was found in the histologic examination. The patient recovered without any complications or functional defects. We recommended clinical and sonographic controls of the tumor location. Since 2 years after surgical intervention, the patient is recurrence-free. 3. Discussion The desmoid ﬁbromatosis is characterized by local aggressive growth without any tendency of metastasis. These very rare tumors can develop in any musculo-aponeurotic structure, and they can be found in all regions of the human body. The commonest site of presentation in case of abdominal wall desmoids seems to be the infraumbilical rectus sheath. The clinical behaviour and the prognosis of the desmoids is very diverse and depends on the anatomic location and the proximity to vitally important organs. A correlation with the familiar intestinal polyposis could be shown [1]. Approx- imately 10–25% of the patients with polyposis present intra- or extra abdominal desmoid tumors [2]. Supposed risk factors of desmoids are previous surgical interventions, pregnancy and hormonal treatment with estrogen. In the presented case, the local tissue trauma of the cesarean section in the clinical history of the patient is one possible risk factor of the disease. The estrogen dependence of the tumors explains the stimulation of their growth by estrogen high ﬂux during pregnancy. Michopoulou et al. published the case of a 37-year-old pregnant presenting a fast growing desmoid of the abdominal wall, ﬁnally reaching a diameter of 20 cm [3]. Viriyaroj et al. [4] found an aggressive ﬁbromatosis of almost 5 kg in the lower abdominal wall of a 17-year- old pregnant. 8 months after resection, the patient did not show any recurrence of the disease. Cormio et al. reported a recurrence-free period of 30 month after surgical resection of a pelvic ﬁbromatosis without any adjuvant treatment [5]. The recurrence of desmoid tumors ranges from 20 to 60% in large retrospective studies. However, in many cases, a recurrence of the aggressive tumors after resection is described [6]. In a retrospective review of 151 patients who underwent a macroscopically complete resection of desmoid tumors, Huang et al. showed a local recurrence rate of 20.5%. Admission status, gender, tumor size, margin status, location, and number of tumors are predictive factors of local recurrence [7]. Salas et al. showed three unfavorable prognostic factors: age less than 37 years, tumor size >7 cm, and extra-abdominal tumor location [8]. A clear diﬀerence in progression free survival was demonstrated according to the number of prognostic factors present. Kumar et al. described a recurrence rate of 25% in a group of 32 patients. The most important factor for recurrence was a tumor size of >5 cm [9]. Bertani et al. described a recurrence-free followup period of 55 months in 14 patients with disease-free margins of >1 cm in intraoperative frozen section [10]. Depending on the tumor size, a reconstruction of the abdominal wall defect with meshes after resection can be necessary [11]. The early detection of a desmoid and the respective Case Reports in Medicine treatment of a smaller tumor can prevent large defects and the mesh reconstruction. However, other authors report that there is no correlation between incomplete resection and recurrency rate. Arrest of growth or even regression is a frequent occurrence even in the absence of any speciﬁc treatment. And the local tissue trauma by surgery might further accelerate the evolution of the disease. Salvi et al. therefore recommend a conservative clinical control [12]. Barbier et al. prefer a wait and see strategy in large tumors, when the resection would cause an important functional and esthetic limitation [13]. Fiore et al. reported a 5-year progression-free survival in almost 50% of a group of 83 patients receiving a wait and see strategy [14]. Anyway, other publications show adjuvant therapeutic approaches to avoid tumor growth and recurrence after surgical resection. Seoud et al. reported about the case of a 32-year-old female with a large pelvic desmoid tumor, who underwent adjuvant radiation after complete resection. A recurrence-free period of 6 years could be shown with this treatment [15]. However, it remains unclear if a wait and see strategy or a surgical treatment without adjuvant radiation would have caused another result. Huang et al. and Kumar et al. [7, 9] for example could not show any signiﬁcant beneﬁt over local recurrence rate with adjuvant radiation. Sportiello et al. reported a case of a desmoid developing in pregnancy with recurrence despite of twice complete resection and adjuvant radiation. Although desmoids normally do not express estrogen receptors [12], the treatment with tamoxifen ﬁnally caused the complete regression of the tumor [16]. Chao et al. also described the complete regression of a tumor recurrence by tamoxifen [17]. Maseelall et al. reported the successful postoperative therapy of a pelvic ﬁbromatosis with Toremifene. The antiestrogenic treatment allowed a recurrence-free period of nine years until the menopause of the pacient [18]. Constantinidou et al. published the successful use of chemotherapy in advanced aggressive ﬁbromatosis with no response to hormonal treatment [19]. In another actual publication the possibility of a therapy with tyrosine kinase inhibition in inoperable tumors is described [20]. Skubitz et al. showed the eﬀectiveness of sunitinib in imatinib-resistant desmoid ﬁbromatosis of the lower extremity [21]. A clear therapeutic approach in all cases of desmoid tumors cannot yet be preferred, and further studies are needed to describe the outcome of the diﬀerent treatment options. In pregnancy, the desmoid tumor of the lower abdominal wall, especially in the area of a cesarean section scar, can be confound with a scar endometriosis. A clear clinical diagnosis of the tumors origin and a diﬀerentiation to endometriosis by palpation and ultrasound are not possible. The intramuscular location of the tumor in ultrasound is an indicator for a desmoid tumor. While desmoids in almost all cases are located close to a muscular aponeurosis, the endometriotic tumors of the abdominal wall can be found most frequently in the subcutaneous region. In the actual literature, only 18 case reports about endometriosis exclusively located in the rectus muscle sheath can be found [22]. A typical sonographic feature of all intramuscular desmoids is the spindle-shaped margin at the tumor ends when scanned along the long axis of the aﬀected muscle.