Primary synovial sarcoma on MRI - a case series and review of the literature.

Purpose: Simple MRI features are mandatory to facilitate the diagnostics of synovial sarcomas, especially for radiolo-gists outside multidisciplinary sarcoma centres. In this case-series and review, we investigate the main appearance of synovial sarcoma on MRI. Material and methods: Fifteen histologically proven primary synovial sarcomas who underwent MRI at 2 different sarcoma centres were included in this case series. Patients and their primary synovial sarcomas were examined for age, localization, mean tumour size (in mm), histological grade (G - according to the Fédération Nationale des Centres de Lutte Contre Le Cancer [FNCLCC]), configuration, T2 signal intensity, presence/absence of "triple sign", heterogeneity/homogeneity, borders (well-defined or infiltrative), and intensity of contrast enhancement on MRI. Additionally, a comprehensive literature review to identify observational studies, reviews, and case-reports assessing MRI features of primary synovial sarcoma was performed. Results: The mean age of the patients was 47.6 years (SD: 17.2). The mean size of primary synovial sarcoma was 59.3 mm (SD: 42). Primary synovial sarcomas were significantly most often multilobulated (n = 12, p < 0.01), heterogeneous (n = 10), and infiltrative (n = 9). Additionally, 3 other primary synovial sarcomas showed the following configurations: ovoid/nodular (n = 2) and fascicular (n = 1). Ovoid/nodular synovial sarcomas were solely depicted as homogeneous with well-defined borders. All tumours showed T2 hyperintense signal and presented with marked contrast enhancement. Conclusions: Primary synovial sarcomas are mainly multilobulated, heterogeneous, and infiltrative tumours. In minor cases, ovoid/nodular or fascicular configurations occur. Knowing the main appearance of synovial sarcoma can help facilitate the diagnostics of primary synovial sarcomas.

Brain MRI findings in neurologically symptomatic COVID-19 patients: a systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been associated with nervous system involvement, with more than one-third of COVID-19 patients experiencing neurological manifestations. Utilizing a systematic review, this study aims to summarize brain MRI findings in COVID-19 patients presenting with neurological symptoms. METHODS: Systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) checklist. The electronic databases of PubMed/MEDLINE, Embase, Scopus, and Web of Science were systematically searched for literature addressing brain MRI findings in COVID-19 patients with neurological symptoms. RESULTS: 25 publications containing a total number of 3118 COVID-19 patients with neurological symptoms who underwent MRI were included. The most common MRI findings and the respective pooled incidences in decreasing order were acute/subacute infarct (22%), olfactory bulb abnormalities (22%), white matter abnormalities (20%), cerebral microbleeds (17%), grey matter abnormalities (12%), leptomeningeal enhancement (10%), ADEM (Acute Disseminated Encephalomyelitis) or ADEM-like lesions (10%), non-traumatic ICH (10%), cranial neuropathy (8%), cortical gray matter signal changes compatible with encephalitis (8%), basal ganglia abnormalities (5%), PRES (Posterior Reversible Encephalopathy Syndrome) (3%), hypoxic-ischemic lesions (4%), venous thrombosis (2%), and cytotoxic lesions of the corpus callosum (2%). CONCLUSION: The present study revealed that a considerable proportion of patients with COVID-19 might harbor neurological abnormalities detectable by MRI. Among various findings, the most common MRI alterations are acute/subacute infarction, olfactory bulb abnormalities, white matter abnormalities, and cerebral microbleeds.

Does the primary soft-tissue sarcoma configuration predict configuration of recurrent tumors on magnetic resonance imaging?

BACKGROUND: Soft-tissue sarcomas (STS) are rare malignancies of the soft tissue. PURPOSE: To assess whether the magnetic resonance imaging (MRI) configuration of primary STS can predict the configuration of a recurring tumor and whether the MRI configuration of multiple recurrences differs in one and the same patient. MATERIAL AND METHODS: Thirty-nine patients with histologically proven recurrent STS were included in this retrospective study and underwent pre- and post-treatment MRI. Three main configurations of primary and recurrent tumors were identified: polycyclic/multilobulated; ovoid/nodular; and streaky. RESULTS: Sixty recurrent lesions were detected: 34 ovoid/nodular; 15 polycyclic/multilobulated; and 11 streaky. Five recurrences were multifocal and eight were bifocal. Of 39 patients, 28 (71.8%) presented one recurrence within the MRI follow-up period (P = 0.006); in 10 patients (25.6%), up to three different configurations of recurring STS were identified in one patient. Recurrences of polycyclic/multilobulated primaries were mostly ovoid/nodular (48%; P = 0.003) or polycyclic/multilobulated (37%; P = 0.014), and recurring ovoid/nodular STS significantly most often showed the same configuration as the primary tumor (85%; P < 0.001). Primary STS with a streaky configuration recurred in all three configurations in roughly equal proportions. Homogeneity/heterogeneity and tumor borders are significantly associated with the configuration of recurrences. CONCLUSION: Primary STS configuration may help predict recurrent tumor configuration when the primary STS had a polycyclic/multilobulated or ovoid/nodular configuration. However, recurrent STS configuration can also differ from primary STS configuration, especially when the primary STS had a streaky configuration, rendering recurrent STS difficult to predict. Different configurations of recurrent STS in one and the same patient are common.

Diagnostic value of MRI for detecting recurrent soft-tissue sarcoma in a long-term analysis at a multidisciplinary sarcoma center.

BACKGROUND: Soft-tissue sarcomas (STS) are rare tumors of the soft tissue. Recent diagnostic studies on STS mainly dealt with only few cases of STS and did not investigate the post-therapeutic performance of MRI in a routine clinical setting. Therefore, we assessed the long-term diagnostic accuracy of MRI for detecting recurrent STS at a multidisciplinary sarcoma center. METHODS: In all, 1055 postoperative follow-up MRIs of 204 patients were included in the study. MRI follow-up scans were systematically reviewed for diagnostic values (true-positive/-negative and false-positive/-negative results) in detecting recurrences. Pathological reports and follow-up MRIs were set as baseline references. RESULTS: The median age of the patients was 55.3 ± 18.2 years. Of the patients, 34.8% presented with recurrences. Here, 65 follow-up scans were true positive, 23 false positive, 6 false negative, and 961 true negative. The overall sensitivity and specificity of MRI for detecting recurrences were 92 and 98%, respectively, with an accuracy of 97%. For intramuscular lesions and after surgery alone the sensitivity was higher (95 and 97%, respectively) than for subcutaneous lesions and surgery with additional radiation therapy (83 and 86%, respectively), at similarly high specificities (96-98%). The 6 false-negative results were found in streaky (n = 2) and small ovoid/nodular (n = 4) recurring lesions. The false-positive lesions imitated streaky (n = 14), ovoid/nodular (n = 8), and polycyclic/multilobulated recurring tumors (n = 1). All false-positive results were found in patients in whom the primary tumors were polycyclic/multilobulated in appearance. CONCLUSION: MRI shows a high diagnostic accuracy for detecting recurrent STS, with a high sensitivity and specificity. The diagnostic accuracy decreases in subcutaneous lesions and after surgery with radiation therapy, compared to intramuscular lesions and surgery alone. Radiologists should pay particular attention to streaky and small ovoid/nodular recurring lesions and patients with polycyclic/multilobulated primary tumors.

Configuration of soft-tissue sarcoma on MRI correlates with grade of malignancy.

BACKGROUND: The aim of the study was to assess whether the configuration of primary soft-tissue sarcoma (STS) on MRI correlates with the grade of malignancy. PATIENTS AND METHODS: 71 patients with histologically proven STS were included. Primary STS were examined for configuration, borders, and volume on MRI. The tumors were divided into high-grade (G3), intermediate-grade (G2) and low-grade (G1) STS according to the grading system of the French Federation of Cancer Centers Sarcoma Group (FNCLCC). RESULTS: 30 high-grade, 22 intermediate-grade and 19 low-grade primary STS lesions were identified. High- and intermediate-grade (G3/2) STS significantly most often appeared as polycyclic/multilobulated tumors (p < 0.001 and p = 0.002, respectively). Low-grade (G1) STS mainly showed an ovoid/nodular or streaky configuration (p = 0.008), and well-defined borders. The appearance of high-, intermediate- and low-grade STS with an ovoid/nodular configuration were mainly the same on MRI. All streaky G3/2 sarcoma and 17 of 20 patients with polycyclic/multilobulated G3 sarcoma showed infiltrative borders. High-grade streaky and polycyclic/multilobulated STS are larger in volume, compared to intermediate- and low-grade STS. CONCLUSIONS: Configuration of STS on MRI can indicate the grade of malignancy. Higher-grade (G2/3) STS most often show a polycyclic/multilobulated configuration, while low-grade STS are mainly ovoid/nodular or streaky. Infiltrative behavior might suggest higher-grade STS in streaky and polycyclic/multilobulated STS.

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

PURPOSE: To assess the diagnostic accuracy of MRI in detecting recurrent aggressive fibromatosis (AF) during long-term follow-up at two multidisciplinary sarcoma centers. METHODS: Seventy-nine patients from two sarcoma centers were included in this IRB-approved study and were examined postoperatively using 1.5-T MRI. MRI follow-up scans were reviewed for true-positive/-negative and false-positive/-negative results. Available pathological reports and MRI follow-ups were set as reference. RESULTS: The median age of the patients was 38.1 ±â€¯15.3 years. Of the patients 27.9 % showed recurrent AF lesions. The most common localizations of AF were the axilla/shoulder (n = 15) and the thigh (n = 11). From 498 postoperative MRI follow-ups, 24 true-positive, 16 false-positive, 6 false-negative, and 452 true-negative MRI follow-ups were identified. The overall sensitivity and specificity for detecting recurrent AF was 80 % and 97 %, respectively. There was no significant difference in the diagnostic accuracy at the two sarcoma centers. All false-negative results were found in small lesions. False-positive results mostly mimicked streaky (n = 10) and small ovoid/nodular (n = 5) lesions. The configuration of recurrent AF was significantly most often fascicular (50 %; p = 0.001-0.005). CONCLUSION: MRI shows a high long-term diagnostic value in detecting AF recurrences. Nevertheless, radiologists should pay close attention when lesions are small, as they may remain undetected. Although the configuration of recurrent AF is most often fascicular, recurrences may also appear in different shapes.

Systematic analysis of post-treatment soft-tissue edema and seroma on MRI in 177 sarcoma patients.

PURPOSE: To assess post-treatment subcutaneous edema, muscle edema, and seroma in MRI after soft-tissue sarcoma (STS) resection with regard to muscle involvement of STS and therapy. METHODS: In all, 177 patients were included and received 1.5-T MRI follow-up examinations after treatment. Post-treatment changes were classified according to type of therapy (therapy 1-surgery; therapy 2-surgery with radiation therapy) and primary tumor localization in soft tissue (localization 1, subcutaneous tissue; localization 2, muscle involvement). Subcutaneous and muscle edema were divided into three grades: grade 0, absence of edema; grade 1, low-to-moderate edema; and grade 2, high-grade edema. RESULTS: The mean age of the patients was 55.7 ± 18.2 years and the mean volume of the resected primary STS was 321.5 cm3. After therapy 1 of a sarcoma in localization 1, patients significantly more often showed low-grade subcutaneous tissue edema and an absence of muscle edema (p < 0.001) than high-grade edema. The risk for grade 2 subcutaneous tissue and muscle edema significantly increased with a tumor in localization 2 (RR = 2.58, p = 0.016 and RR = 15, p = 0.0065/RR = 2.05 , p = 0.021, respectively) and after therapy 2 (RR = 15, p = 0.0087 and RR = 2.05, p < 0.0001, respectively). Of the patients with sarcoma in localization 2, 88% developed grade 2 muscle edema after therapy 2; 40% of the patients developed post-treatment seroma. The risk for seroma is significantly higher after surgery and radiation therapy than after surgery alone (p < 0.001). CONCLUSION: High-grade postoperative subcutaneous and muscle edema are significantly associated with muscle involvement of primary STS both in patients with and without radiation therapy. The risk for seroma is significantly higher after surgery with additional radiation therapy than after surgery alone.

Appearance of recurrent dermatofibrosarcoma protuberans in postoperative MRI follow-up.

PURPOSE: To analyze the appearance of recurrent dermatofibrosarcoma protuberans (DFSP) in postoperative MRI follow-up and to assess the occurrence of postoperative soft tissue changes detected in MRI. METHODS: A total of 464 MRI follow-up scans of 32 patients with histologically proven diagnosis of DFSP were analyzed. MR imaging was performed using a 1.5T MRI system. Recurrent DFSP was examined for signal intensity, contrast behavior, appearance, and extent in MRI. RESULTS: The mean age of the patients was 44,5±17,1 years. Recurrences of DFSP occurred 26±23.3 months after primary tumor resection in the mean (Min.: 9, Max.: 60). In 25% of the patients (n = 8), recurrences of DFSP were detected. Recurrent DFSP most often showed a nodular and homogeneous configuration with well-defined borders and marked contrast enhancement, and a hyperintense signal in PD-weighted and turbo inversion recovery magnitude sequences. All recurrences were well detected in the follow-up MRIs regardless of the performed plastic surgery procedure. Lateral and depth margins had no significant impact on the local recurrence rate. In all, 88% of the patients developed subcutaneous tissue edema (p < 0.01), followed by muscle edema (34%, p = 0.02), and postoperative seroma (22%). CONCLUSION: Recurrent DFSP mainly appear uniform and clearly delimitable on MRI as nodular, homogeneous, and well-defined lesions with marked contrast enhancement. Therefore, MRI is a valuable tool for postsurgical follow-up. Nearly all patients develop subcutaneous edema after the resection of DFSP.

Malignant peripheral nerve sheath tumours in magnetic resonance imaging: primary and recurrent tumour appearance, post-treatment changes, and metastases.

PURPOSE: To analyse the appearance of primary and recurrent malignant peripheral nerve sheath tumours (MPNSTs) in magnetic resonance imaging (MRI) with a focus on configuration, and to assess the occurrence of loco-regional post-treatment changes and metastases during post-treatment follow-up. MATERIAL AND METHODS: Twenty patients with histologically proven MPNST underwent post-treatment 1.5 T MRI. Primary and recurrent MPNSTs were examined for configuration, contrast enhancement, extent, and signal intensity in MRI. Loco-regional post-treatment changes and information on metastases were extracted from the follow-up. RESULTS: MPNSTs occurred most often in the extremities (p = 0.006). Twenty per cent (n = 4) of the patients developed recurrences, with a total of 24 lesions. Recurrent MPNSTs were significantly smaller than primary MPNSTs (p = 0.003). Primary MPNSTs mostly occurred unifocally as multilobulated or ovoid and heterogeneous lesions with mostly well-defined borders. Recurrent MPNSTs purely occurred multifocally as mostly nodular (p < 0.001), multilobulated, or ovoid lesions. 80%, 65% and 30% of the patients showed post-treatment subcutaneous oedema (p = 0.002 to 0.03), muscle oedema (p = 0.02), and seroma, respectively. Twenty-five per cent (n = 5) of patients presented metastases during follow-up. The relative risk in patients with recurrences to develop lung or lymph node metastases is eightfold (p = 0.056). CONCLUSIONS: While primary MPNSTs mostly appear unifocally as multilobulated or ovoid lesions, recurrent MPNSTs purely occur multifocally as mostly nodular lesions. Subcutaneous and muscle oedema are very common loco-regional post-treatment changes. Patients with recurrences have a higher risk for lung and lymph node metastases.

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

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 ±â€Š2.6 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: · Primary aggressive fibromatosis mostly has a fascicular configuration with heterogeneous contrast enhancement. · Recurrent aggressive fibromatosis usually has a fascicular configuration with heterogeneous/homogeneous contrast enhancement. · Patients within the first 9 post-operative months and up to 25 years of age have a significantly higher risk for recurrences. · Muscle edema after resection of primary aggressive fibromatosis is associated with a significantly higher risk for recurrences. CITATION FORMAT: · Sedaghat S, Surov A, Krohn S et al. Configuration of Primary and Recurrent Aggressive Fibromatosis on Contrast-Enhanced MRI with an Evaluation of Potential Risk Factors for Recurrences in MRI Follow-Up. Fortschr Röntgenstr 2020; 192: 448 - 457.