Configuration of Primary and Recurrent Aggressive Fibromatosis on Contrast-Enhanced MRI with an Evaluation of Potential Risk Factors for Recurrences in MRI Follow-Up

Abstract

Purpose To analyze the appearance of primary and recurrent aggressive fibromatosis (AF) on MRI with a focus on configuration and to determine potential risk factors for recurrences detected on MRI follow-up scans. Methods From 79 consecutive patients with histologically proven diagnosis of AF, 39 patients underwent a minimum of four 1.5 T MRI follow-up scans after resection of primary AF between 2008 and 2018. The primary and recurrent tumors were radiographically examined for configuration, limitation and extent on MRI. Epidemiological data and loco-regional subcutaneous edema, muscle edema and post-operative seroma were included. Results The mean age of the patients was 39 ± 2.6 years. Primary and recurrent AF most often occurred in the thigh. The main appearance of primary AF was significantly most often fascicular (p = 0.001–0.01) with heterogeneous and marked contrast enhancement. 21 % (n = 8) of the patients developed recurrences of AF. A fascicular configuration with homogeneous/heterogeneous contrast enhancement was the main appearance of recurrent AF, but recurrent AF appeared nodular, polycyclic, ovoid or streaky/flat as well. Recurrent AF significantly most often occurred within the first 9 months after primary tumor resection (p = 0.009), especially in patients up to 25 years of age (RR = 6.1; 95 % CI: 1.8–20.9; p = 0.004). The cases of recurrent AF were altogether significantly smaller than the primary tumors (p = 0.001). Post-treatment subcutaneous and muscle edema were present in 77 % and 56 %, respectively. Patients with muscle edema after primary tumor resection had a significantly higher risk for AF recurrences (relative risk ratio (RR) = 1.8; 95 % CI: 1.16–2.8; p = 0.0096). There was no significant difference detected in patients with complete or incomplete resection of the primary tumor. Conclusion Primary and recurrent aggressive fibromatosis has a mostly fascicular configuration, but may appear ovoid, nodular, streaky/flat or polycyclic as well. High risks for tumor recurrences are detected for patients up to 25 years of age, patients within the first 9 post-operative months and patients with muscle edema after primary tumor resection. Key points: Citation Format

Long-term diagnostic value of MRI in detecting recurrent aggressive fibromatosis at two multidisciplinary sarcoma centers

“…Due to the relatively high rate of recurrences and because AF lesions are clinically often silent, the focus of postoperative surveillance is on postoperative imaging. MRI is the imaging modality of choice for both preoperative staging of AF and also for postoperative surveillance of primary AF [9,11,25]. Nowadays, contrast-enhanced MRI is usually performed in patients with soft-tissue tumors, both at primary diagnosis and at MRI follow-up, as distinguishing postoperative soft-tissue changes and recurrent tumor often poses a challenge on conventional MR sequences.…”

“…The overall sensitivity and specificity in our study was 80 % and 97 %, respectively. In our experience, post-treatment surveillance of AF is more challenging than for STS, as AF is normally located close to the muscle fascia and may infiltrate the muscle tissue, which may render it difficult to distinguish AF recurrences from the surrounding muscle tissue, especially when soft-tissue edema is present [2,11]. The treatment of choice for AF is wide excision, often with additional radiation therapy [9].…”

“…The extremities are the main localization of AF, accounting for approximately 70 % of all AF [9,4]. AF has a high rate of recurrence of up to 77 %, even after wide local excision [3,10,11]. MRI is the imaging modality of choice for postoperative surveillance of patients with soft-tissue tumors [12][13][14].…”

“…On MRI, AF is often reported to show a heterogeneous appearance on T1-weighted and T2-weighted images and enhances avidly after intravenous administration of contrast agent [15]. Additionally, AF is described as having an ovoid or infiltrative appearance [3,16] and is often difficult to distinguish from soft-tissue sarcomas or from postoperative and postradiogenic soft tissue on MRI [3,11]. Nevertheless, studies on the diagnostic accuracy of MRI in the postoperative surveillance of AF do not exist yet.…”

“…Therefore, we analyzed the diagnostic value of MRI in detecting recurrent AF in the long-term postoperative follow-up at two multidisciplinary sarcoma centers. Furthermore, we assessed the configurations of recurrent AF on MRI, as a recent study revealed that primary AF typically shows a fascicular configuration [11].…”