A child with intravascular fasciitis mimicking deep vein thrombosis: a case report.

BACKGROUND: Intravascular fasciitis (IF) is a benign, reactive, myofibroblastic proliferation that originates from the superficial or deep fascia of small / medium-sized arteries and veins. CASE REPORT: An 8-year-old male patient was admitted to a health center with the complaint of swelling in the inguinal region. Lower extremity venous Doppler ultrasonography showed deep vein thrombosis (DVT) of the femoral vein and anticoagulation with low-molecular weight heparin (LMWH) was initiated. The patient was referred to our center for follow-up. The D-dimer level was detected within normal limits. Doppler ultrasonography was repeated and showed an intraluminal expanding mass lesion with increasing vascularity, without distinct borders and LMWH was discontinued. This lesion at the sapheno-femoral junction was excised surgically and the histopathological examination revealed intravascular fasciitis. CONCLUSION: Clinicians should be aware that the clinical findings of IF may mimic sarcoma and thrombosis.

Development of clinical and magnetic resonance imaging-based radiomics nomograms for the differentiation of nodular fasciitis from soft tissue sarcoma.

BACKGROUND: Accurate differentiation of nodular fasciitis (NF) from soft tissue sarcoma (STS) before surgery is essential for the subsequent diagnosis and treatment of patients. PURPOSE: To develop and evaluate radiomics nomograms based on clinical factors and magnetic resonance imaging (MRI) for the preoperative differentiation of NF from STS. MATERIAL AND METHODS: This retrospective study analyzed the MRI data of 27 patients with pathologically diagnosed NF and 58 patients with STS who were randomly divided into training (n = 62) and validation (n = 23) groups. Univariate and multivariate analyses were performed to identify the clinical factors and semantic features of MRI. Radiomics analysis was applied to fat-suppressed T1-weighted (T1W-FS) images, fat-suppressed T2-weighted (T2W-FS) images, and contrast-enhanced T1-weighted (CE-T1W) images. The radiomics nomograms incorporating the radiomics signatures, clinical factors, and semantic features of MRI were developed. ROC curves and AUCs were carried out to compare the performance of the clinical factors, radiomics signatures, and clinical radiomics nomograms. RESULTS: Tumor location, size, heterogeneous signal intensity on T2W-FS imaging, heterogeneous signal intensity on CE-T1W imaging, margin definitions on CE-T1W imaging, and septa were independent predictors for differentiating NF from STS (P < 0.05). The performance of the radiomics signatures based on T2W-FS imaging (AUC = 0.961) and CE-T1W imaging (AUC = 0.938) was better than that based on T1W-FS imaging (AUC = 0.833). The radiomics nomograms had AUCs of 0.949, which demonstrated good clinical utility and calibration. CONCLUSION: The non-invasive clinical radiomics nomograms exhibited good performance in the differentiation of NF from STS, and they have clinical application in the preoperative diagnosis of diseases.

Ultrasound features and differential diagnosis for superficial nodular fasciitis.

BACKGROUND: Nodular fasciitis (NF) has nonspecific clinical manifestations and is often misdiagnosed as sarcoma. The investigations of imaging methods for NF were limited. OBJECTIVE: To analyze the ultrasound (US) features of NF, and to evaluate the diagnostic value of US for NF. MATERIALS AND METHODS: A total of 61 NF patients were recruited retrospectively, and 551 lesions in the subcutaneous fat layer were included for comparison. We evaluated the ultrasound features of the patients and divided the NF cases into three types. Chi-square test or Fisher exact test were conducted to detect the potential difference in the distributions of three types in the two groups. RESULTS: Among the 61 NF cases, 65.6% were in the upper extremities (n = 40). The proportion of type 1, 2, and 3 were 57.4%, 24.6%, and 18.0%, respectively. NF were significantly more likely locating in the upper extremities than the other soft tissue tumors (p < 0.001). Type 1 and type 2 of sonographic features were significantly more commonly observed in NF than other soft tissue tumors among the three types (p < 0.001). CONCLUSION: The type 1 and type 2 of US features can help to distinguish NF from other lesions. US has great potential to improve the diagnostic accuracy and reduce the unnecessary surgery.

Fibroblastic and Myofibroblastic Soft-Tissue Tumors: Imaging Spectrum and Radiologic-Pathologic Correlation.

Fibroblastic and myofibroblastic tumors are a variable group of neoplasms ranging from benign to malignant. These lesions may affect patients of any age group but are more frequently encountered in the pediatric population. Patient clinical presentation depends on the location, growth pattern, adjacent soft-tissue involvement, and pathologic behavior of these neoplasms. In the 2020 update to the World Health Organization (WHO) classification system, these tumors are classified on the basis of their distinct biologic behavior, histomorphologic characteristics, and molecular profiles into four tumor categories: (a) benign (eg, fibrous hamartoma of infancy, nodular fasciitis, proliferative fasciitis, fibroma of the tendon sheath, calcifying aponeurotic fibroma); (b) intermediate, locally aggressive (eg, desmoid fibromatosis); (c) intermediate, rarely metastasizing (eg, dermatofibrosarcoma protuberans, myxoinflammatory fibroblastic sarcoma, low-grade myofibroblastic sarcoma, infantile fibrosarcoma); and (d) malignant (eg, sclerosing epithelioid fibrosarcomas; low-grade fibromyxoid sarcoma; myxofibrosarcoma; fibrosarcoma, not otherwise specified). Detection of various components of solid tumors at imaging can help in prediction of the presence of corresponding histopathologic variations, thus influencing diagnosis, prognosis, and treatment planning. For example, lesions with a greater myxoid matrix or necrotic components tend to show higher signal intensity on T2-weighted MR images, whereas lesions with hypercellularity and dense internal collagen content display low signal intensity. In addition, understanding the radiologic-pathologic correlation of soft-tissue tumors can help to increase the accuracy of percutaneous biopsy and allow unnecessary interventions to be avoided. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Fasciitis ossificans: imaging features, histology, and differential diagnosis.

AIM: To describe the imaging features of fasciitis ossificans and its histopathological features. MATERIALS AND METHODS: Using a word search of existing pathology reports at the Mayo Clinic, six cases of fasciitis ossificans were identified. The clinical history, histology, and available imaging of the affected area were reviewed. RESULTS: Imaging consisted of radiographs, mammograms, ultrasound images, bone scintigraphs, computed tomography (CT), and magnetic resonance imaging (MRI) images. All cases demonstrated a soft-tissue mass. The characteristic MRI appearance was a T2 hyperintense enhancing mass with surrounding soft-tissue oedema. Peripheral calcifications were seen on radiographs, CT, and/or ultrasound. Histological sections showed distinct zonation, with nodular fasciitis-like zones of myofibroblastic proliferation, which merged with osteoblasts that rim the ill-defined trabeculae of woven bone and became continuous with the mature lamellar bone surrounded by a thin layer of compressed fibrous tissue. CONCLUSION: Imaging features of fasciitis ossificans are that of an enhancing soft-tissue mass located within a fascial plane with prominent surrounding oedema and mature peripheral calcification. Imaging and histology are that of myositis ossificans but occurring within the fascia. It is important that radiologists are aware of the diagnosis of fasciitis ossificans and appreciate its similarity to myositis ossificans. This is particularly important in anatomical locations with fascias but no muscle. Given the radiographic and histological overlap between these entities, nomenclature that encompasses both could be considered in the future.

Diffuse fasciitis with eosinophilia in boys: a case-based review.

Diffuse fasciitis with eosinophilia (EF) is a rare condition classified as a part of the connective tissue disorders. The clinical presentation of this condition can be diverse, however the main symptoms include symmetrical swelling and hardening of distal parts of limbs accompanied by peripheral eosinophilia. The diagnostic criteria are not specified. In inconclusions cases Magnetic Resonance Imaging (MRI) and skin to muscle biopsy may be useful. The pathogenesis and ethiology remain unknown, but extensive physical exertion, certain infectious factors, such as Borrelia burgdorferi, or medications may serve as a trigger. EF affects equally women and men, mainly in their middle age, however the disease can occur at any age. The standard therapy contents gluccocorticosteroids. As a second-line treatment, methotrexate is usually chosen. In this article we compare world reports of EF in paediatric patients with the cases of two adolescent male patients recently hospitalized in the Department of Paediatric Rheumatology.

Intravascular fasciitis of the scalp as a complication of ICP monitor placement: a case report and review of the literature.

BACKGROUND/IMPORTANCE: There are only 56 documented cases of intravascular fasciitis, a rare variant of nodular fasciitis. Of these cases, only 2 involved the scalp. This lesion is amenable to surgical resection, making it important to differentiate it from soft tissue malignancies of the scalp. CLINICAL PRESENTATION: We report an unusual case of intravascular fasciitis involving the scalp at the site of an intracranial pressure (ICP) monitor of a 13-year-old male patient. The lesion was surgically excised with no recurrence upon 1-month follow-up. CONCLUSION: Intravascular fasciitis is a benign, reactive proliferation of soft tissue that may arise at sites of prior trauma. It appears as a soft, painless, mobile lesion, and immunohistochemical studies are required to differentiate it from malignant lesions. The standard of care is surgical resection of the lesion.

Infantile Cranial Fasciitis: A Clinicopathologic Evaluation.

OBJECTIVE: To investigate the clinicopathologic features, immunophenotype, molecular genetic changes, and differential diagnosis of cranial fasciitis (CF). METHODS: The clinical manifestations, imaging, surgical technique, pathologic characteristics, special staining, and immunophenotype, as well as break-apart fluorescence in situ hybridization assay for USP6 of 19 CF cases were analyzed, retrospectively. RESULTS: The patients were 11 boys and 8 girls, aged 5 to 144 months, with a median age of 29 months. There were 5 cases (26.31%) in the temporal bone, 4 cases (21.05%) in the parietal bone, 3 cases (15.78%) in the occipital bone, 3 cases (15.78%) in the frontotemporal bone, 2 cases (10.52%) in the frontal bone, 1 case (5.26%) in the mastoid of middle ear, and 1 case (5.26%) in the external auditory canal. The main clinical manifestations were painless, with the presentation of masses that grew rapidly and frequently eroded the skull. There was no recurrence and no metastasis after the operation. Histologically, the lesion consists of spindle fibroblasts/myofibroblasts arranged in bundles, braided or atypical spokes. Mitotic figures could be seen, but not atypical forms. Immunohistochemical studies showed diffuse strong positive SMA and Vimentin in all CFs. These cells were negative for Calponin, Desmin, ß-catenin, S-100, and CD34. The ki-67 proliferation index was 5% to 10%. Ocin blue-PH2.5 staining showed blue-stained mucinous features in the stroma. The positive rate of USP6 gene rearrangement detected by fluorescence in situ hybridization assay was about 10.52%, and the positive rate was not related to age. All patients were observed for 2 to 124 months and showed no signs of recurrence or metastasis. CONCLUSIONS: In summary, CF was a benign pseudosarcomatous fasciitis that occurs in the skull of infants. Preoperative diagnosis and differential diagnosis were difficult. Computed tomography typing might be beneficial for imaging diagnosis, and pathologic examination might be the most reliable way to diagnose CF.

Periosteal Fasciitis With Unusual Radiologic Features Harboring a Novel STAG1::USP6 Fusion Gene.

Periosteal fasciitis is a subtype of nodular fasciitis originating from the periosteum. The diagnosis can be challenging and requires radiologic-pathologic correlation. Advances in molecular analysis confirmed that nodular fasciitis and its related lesions harbor a USP6 gene rearrangement with one of the several potential partners. Herein, we report a case of periosteal fasciitis with metaplastic bone formation detected incidentally during a radiologic survey for breast carcinoma. Radiologic examination revealed a 2.4 cm, heterogeneous, avidly enhancing lesion of the right femoral distal metaphysis concerning for low-grade periosteal chondrosarcoma. Histological examination of a core needle biopsy revealed a tumor composed of bland spindle cells with myofibroblastic and osteoblastic phenotypes admixed with immature bone and cartilaginous elements. Molecular analysis revealed a novel STAG1::USP6 fusion that helped arrive at the right diagnosis and further expands the molecular profile of USP6-associated neoplasms.

Extremely rare occurrence of multiple cranial fasciitis: A case report.

Cranial fasciitis (CF) is a rare, rapidly growing, benign fibroproliferative lesion of the skull in the pediatric population. It is characterized by benign mesenchymal proliferation of spindle cells arranged as short, intersecting loose fascicles within a fibromyxoid stroma, and mostly appears as a single mass. A surgical excision with clear surgical margins is definitively curative for CF. Up to date only two cases with multiple CF have been reported in the literature. In this report, we describe a 1-year-old girl with multiple locations of CF, as the first case to be reported in the Turkish population. The radiological and morphological findings of our case were comparable with the observations of the two previous reports in the literature. Histopathological examination remains to be the gold-standard for differential diagnosis of CF, as the treatment of this lesion differs from other malignancies of the skull in the pediatric population.

Intraneural Nodular Fasciitis of the Dorsal Scapular Nerve: Case Report and Review of the Literature.

BACKGROUND: Nodular fasciitis is a benign neoplasm occurring predominantly in the subcutaneous tissue. There have been nine intraneural occurrences described in the literature. CASE REPORT: A 37-year-old woman presented with numbness and tenderness in her left shoulder and scapula and a slightly dropped left shoulder, without history of trauma. A magnetic resonance imaging (MRI) of the cervical spine showed a well-circumscribed oval mass deep to the levator scapula muscle. Due to persisting symptoms and an unknown nature of the process, surgical excision was performed, and histopathologic analysis confirmed diagnosis of a benign fibroblastic/myofibroblastic neoplasm, nodular fasciitis. The postoperative course was uneventful and the patient was without symptoms at 4 months of follow-up. METHODS: We reviewed the available literature (PubMed, Google Scholar), with nine published cases of intraneural nodular fasciitis. The reported clinical, radiologic, and histopathologic parameters were evaluated and compared. DISCUSSION: Most of the cases reported in the literature were symptomatic, with tenderness and palpability being the main symptoms. Six of the reported cases occurred in the forearm, whereas three were in the leg. To the best of our knowledge, ours is the first reported case of nodular fasciitis occurring in the trunk. Ours is the only case to display desmin positivity, which supports the reactive hypothesis of nodular fasciitis. CONCLUSION: Intraneural nodular fasciitis is an extremely rare diagnosis. Due to its benign natural course, a multidisciplinary approach with this extremely rare diagnosis in mind is needed to avoid overtreatment.

Orbital nodular fasciitis in the pediatric population: a case report and review of the literature.

A 10-month-old female presented with a rapidly growing, painless mass in the right upper eyelid. Due to suspected malignancy, she underwent an urgent biopsy. Histopathological and immunohistochemical analyses revealed nodular fasciitis. Here, we describe the case and perform a literature review of orbital nodular fasciitis in the pediatric population.

[Solitary dorsal paravertebral tumor: radiological and histopathological characterization of a pediatric case of nodular fasciitis].

Nodular fasciitis is a benign soft tissue lesion with rapid fibroblastic or myofibroblastic proliferation, rarely observed in pediatric patients. Here, we present the case of a seven-year-old boy with no relevant medical records, in whom an asymptomatic dorsal tumor was incidentally identified. Magnetic resonance imaging showed a left dorsal paravertebral lesion with hypointensity on T1, hyperintensity on T2, peripheral contrast enhancement, and the so-called fascial tail sign. Complete surgical resection of the lesion was achieved. The histopathological study showed a proliferation of spindle or stellate cells with nuclei without atypia in a myxoid or collagenized stroma. The immunohistochemical profile showed positivity for smooth muscle actin, muscle-specific actin antibody HHF35, and calponin. The lesion was diagnosed as nodular fasciitis, an entity with broad and complex differential diagnosis. Presence of specific radiological signs and adequate immunohistochemical characterization of the lesion help perform an accurate diagnosis.

Cranial fasciitis in children: clinicoradiology features and management.

BACKGROUND: Cranial fasciitis (CF) is a rare benign fibroproliferative lesion of the skull. To date, the summarized radiologic characteristics and the subtype of the disease have not been reported. our purpose was to summarize the characteristic clinicoradiology features and management of CF and to improve the knowledge of radiologists and clinicians. METHODS: We searched our institution's database and retrieved the clinical and radiologic data of CF patients confirmed by histopathological examination. The clinicoradiology features and management of CF were analysed retrospectively. RESULTS: A total of 14 CF patients were included. A total of 85.7% of the patients presented with a painless, firm, nonmobile and single mass. Tenderness and multiple masses were found in 14.3% of the patients. The mass was clearly increased in 2 patients and gradually increased in 5 patients in the short term. We divided these patients into three types based on the CT characteristics. The characteristic features of type I (9 patients) presented as an expansive and osteolytic bone destruction with a soft tissue mass. Type II (2 patients) presented as a scalp mass with mild erosion of the outer skull plate. Type III (3 patients) presented as a scalp mass without skull destruction. All patients underwent surgical resection. For type I patients, craniectomy and cranioplasty were performed. For type II patients, complete excision of the scalp mass with local skull curettage was performed. For type III patients, complete excision of the scalp mass was performed. There were no cases of recurrence after follow-up. CONCLUSIONS: CF usually presents as a painless, firm, nonmobile and single mass with a clear boundary. There are generally three types of MSCT findings: bone destruction with a soft tissue mass, a scalp mass with erosion of the skull and a scalp mass. Different management strategies should be utilized for the various types of CF.