Nodular Fasciitis Research Articles

The value of morphology: osteoclast-like cells in soft tissue tumours

<b>Introduction:</b> Nodular fasciitis is a rare, benign proliferative process of connective tissue that, due to its rapid growth and histopathological appearance, is often misdiagnosed as a malignant tumor. It most commonly occurs in the soft tissues of the extremities, trunk, and neck, primarily in young adults. However, it can also present in children, though less frequently, and typically affects the head and neck region in this group. Diagnosis relies on imaging studies, histopathological analysis, and, in selected cases, genetic testing to confirm the condition. Standard treatment involves surgical excision of the lesion, which usually results in complete recovery.<b>Case report:</b> The article describes a case of nodular fasciitis of the larynx in a newborn, causing acute laryngeal dyspnea.<b>Conclusions:</b> Although nodular fasciitis is rare, it should be considered in the differential diagnosis of acute upper airway obstruction. Precise diagnostic evaluation is essential to avoid misdiagnosis and the implementation of unnecessarily aggressive treatment.

Nodular fasciitis is a benign, self-limiting, and rapidly proliferating fibroblastic/myofibroblastic lesion. Nodular fasciitis, in the head and neck region, in particular, poses significant diagnostic challenges due to its rapid growth and resemblance to malignant neoplasms. In this single-center observational study, we report on 50 patients who presented with nodular fasciitis in the head and neck region, with a male-to-female patient ratio of 1.94:1 and an age range of 1.5 to 78.5 years. The lesions were primarily located in the cheek (38%), followed by the scalp (16%), orbital region (12%), nasal region (10%), neck (10%), auricular region (6%), supraclavicular region (4%), and maxillary and zygomatic regions (each 2%). These lesions exhibited typical histologic features, including spindle-shaped cells with a predominantly fascicular arrangement, along with "tissue culture," haphazard, storiform, and sheeting patterns. Collagen, keloid-type fibers, and a mucin/myxoid matrix were noted. Extravasated erythrocytes, abundant mitoses, lymphoid infiltration, and multinucleated giant cells were commonly observed. There was positive expression of immunostains ASMA and CD10. Follow-up demonstrated a benign clinical course, with only one recurrence despite its rapid growth and similarity to malignancy. This study aims to highlight key clinical and histopathological features of nodular fasciitis in the head and neck region to prevent misclassification and unnecessary treatment, ultimately improving patient outcomes.

To investigate immunohistochemical expression of the E26 transformation-specific factors (ETS)-related gene (ERG) in a large number of soft tissue neoplasms using a tissue microarray technique. 489 cases of soft tissue neoplasms, including benign and malignant entities, were collected from the files of the respective institutions and constructed into tissue microarrays. Tissue microarrays were stained for ERG immunohistochemistry using two antibodies, EP111 and EPR3864. A total of 25 cases (5.1%) were identified that were positive for ERG using the monoclonal antibody EP111 and 15 cases (3%) using the monoclonal antibody EPR3864, including rhabdomyosarcoma, peripheral nerve sheath tumours, synovial sarcoma, myxofibrosarcoma, epithelioid sarcoma, dermatofibrosarcoma protuberans, low-grade fibromyxoid sarcoma, nodular fasciitis and dedifferentiated liposarcoma. The most consistently stained tumours included synovial sarcoma, rhabdomyosarcoma and benign and malignant peripheral nerve sheath tumours. Various other fibroblastic proliferations, including dermatofibrosarcoma protuberans, myxofibrosarcoma, low-grade fibromyxoid sarcoma and nodular fasciitis, also showed positive staining in a small fraction of cases. One case of dedifferentiated liposarcoma showed nuclear positivity for ERG, and one case of epithelioid sarcoma was also positive. This study supports the value of ERG as a highly sensitive and specific marker for the diagnosis of vascular neoplasms but also demonstrates rare cases of aberrant staining and underscores the need to assess soft tissue tumours using a panel of stains and interpret the results of immunohistochemistry in the appropriate histological and clinical context.

Cranial fasciitis (CF) is a rare benign myofibroblastic proliferation predominantly affecting the pediatric skull, often mimicking malignant processes radiologically. While CF is well described pathologically, its imaging characteristics remain underreported, especially in orbital involvement. We retrospectively reviewed the literature through PubMed and Scopus using the search terms "cranial fasciitis" and "nodular fasciitis AND orbit." We included only cases localized to the craniofacial region. Demographic, imaging, anatomical origin, and follow-up data were extracted. We categorized CF into five distinct types based on tissue involvement. Additionally, we report a new case of CF with orbital extension in a 32-month-old male, including detailed imaging and histopathologic findings. A total of 142 CF cases were identified across 73 studies, including our case. Median age at diagnosis was 2years, with a male predominance (1.5:1). Most cases presented with subcutaneous scalp masses (88.7%), often associated with bone erosion or intracranial extension. Only four cases involved the orbit. The most common imaging type was subcutaneous mass with calvarial destruction (45.1%). MRI findings typically included T2 hyperintensity, T1 hypo- to isointensity, marked contrast enhancement, and facilitated diffusion. Recurrence was rare (7.3%). This study represents the largest review of CF to date and is the first to systematically describe imaging subtypes. Orbital involvement, while rare, may mimic aggressive lesions and lead to misdiagnosis. Recognizing imaging patterns of CF is essential for accurate diagnosis, avoiding overtreatment, and guiding appropriate surgical management in pediatric patients.

Although nodular fasciimmon and can occur in various anatomical locations, its occurrence within a nerve is extremely rare. Nodular fasciitis usually resolves spontaneously after partial resection. However, it often presents diagnostic challenges due to its resemblance to malignant diseases, resulting in excessive treatments such as extended nerve excision and nerve transplantation. We report two cases of intraneural nodular fasciitis. A 37-year-old woman presented with left upper limb numbness and pain, without trauma history. Preoperative ultrasound was performed. Subtotal resection of the mass in the superficial branch of the radial nerve was conducted. Postoperative pathology and immunohistochemistry confirmed intraneural nodular fasciitis. At 9-month follow-up, symptoms resolved with no recurrence of the mass. A 15-year-old female presented with progressive right lower limb numbness, later accompanied by pain, distal muscle weakness, and difficulty in lifting the foot. Preoperative ultrasound and magnetic resonance imaging were performed. The mass within the sciatic nerve was completely removed. Postoperative pathology and immunohistochemistry confirmed intraneural nodular fasciitis. At 3-month follow-up, symptoms resolved with no recurrence of the mass. Accurate diagnosis of intraneural nodular fasciitis is crucial to prevent unnecessary treatment. Its ultrasound and magnetic resonance imaging features lack specificity. Preoperative biopsy using ultrasound or computed tomography guidance may be considered if necessary and safe. The histopathological features for intraneural nodular fasciitis exhibits spindle cells in a tissue-culture-like pattern within a richly myxoid matrix, abundant capillaries, inflammatory cell infiltration, frequent mitotic figures without atypia, and infiltrative margins. Immunohistochemically, intraneural nodular fasciitis is characterized by SMA(+) and S100(-). Surgical excision of the lesion is necessary to prevent neurological deficits. And the vast majority of intraneural nodular fasciitis cases spontaneously regress after subtotal resection. A comprehensive diagnostic approach is recommended when intraneural nodular fasciitis is suspected. This article analyzes the diagnostic workup and pathogenesis of all 13 reported intraneural nodular fasciitis cases (including our two), aiming to aid clinicians in achieving precise diagnosis and avoiding overtreatment.

Nodular fasciitis is a pseudosarcomatous, self-limited lesion composed of fibroblasts and myofibroblasts. Craniofacial lesions are more common in pediatric patients. This report presents a rare case of nodular fasciitis involving the face of an adult patient. A 32-year-old woman presented with a painless subcutaneous mass at the right zygomatic region, with one year of duration. The diagnostic hypotheses were epidermoid cyst and neurofibroma. An excisional biopsy was performed, and the microscopic examination exhibited an admixture of spindle-shaped cells and acellular areas associated with prominent collagen bands. No cellular atypia was observed. Immunohistochemical findings demonstrated positivity for alpha-SMA, HHF35, and beta-catenin. Tumor cells were negative for STAT6. The final diagnosis was nodular fasciitis. The patient has not presented any recurrences so far. Clinicians and pathologists must be capable to distinct nodular fasciitis and malignant tumors to avoid misdiagnosis and overtreatment.

Nodular fasciitis is a benign, pseudoneoplastic condition often misdiagnosed as sarcoma due to its rapid growth, high cellularity, and mitotic activity. Herein is reported a case of a 7-year-old patient with a painless, enlarging nodule in the left superolateral orbit. Ultrasound revealed a 7.5 mm cystic mass, which was excised via an upper eyelid crease anterior orbitotomy. Histopathologic studies showed benign spindle cells, and molecular testing identified a UBC::USP6 fusion, confirming the diagnosis of nodular fasciitis. Nodular fasciitis is most common in the limbs, trunk, and head or neck region, with fewer than 1% of cases occurring in the orbit. Molecular testing is critical in differentiating this condition from malignancies. Complete surgical excision is the preferred treatment, with a low recurrence rate of 1% to 2%. This is the first reported pediatric case of orbital nodular fasciitis with a UBC::USP6 fusion mutation.

BackgroundNodular fasciitis (NF) shrinks spontaneously; however, few reports have focused on its self-regression. This study investigated NF shrinkage.MethodsWe retrospectively reviewed 55 patients with NF who visited Nagoya University Hospital. Twenty-three patients were followed-up and evaluated for shrinkage. Factors affecting the occurrence of deep layers and ≥ 50% tumor volume shrinkage were investigated. The proportion of patients who achieved ≥ 50% tumor volume shrinkage, time to ≥ 50% tumor volume shrinkage, and tumor volume compared with baseline at the last follow-up were assessed.ResultsThe presence of deep layers was significantly associated with longer symptom duration and more frequent biopsies. The proportion of patients who achieved ≥ 50% tumor volume shrinkage, time to ≥ 50% tumor volume shrinkage, and tumor volume compared to baseline at the last follow-up were 17 of 23 patients (74%), median 104 days (19–973)days, and median 24% (7–99%), respectively. Shorter duration of symptoms was significantly associated with ≥ 50% tumor volume shrinkage.ConclusionApproximately three-quarters of the patients demonstrated ≥ 50% tumor volume shrinkage, suggesting that wait-and-see concept was acceptable for NF. The better understanding of NF shrinkage showed that proper follow-up is necessary for patients with NF.

Many subtypes of bone and soft tissue tumours harbour specific chromosome translocations leading to chimeric fusion genes. The identification of these specific fusion genes is the basis of molecular diagnoses in such tumours. Break-apart FISH is a robust method that is commonly used to identify these translocations and provide diagnostic support to histological interpretations. The signal patterns of the break-apart probes are usually easily interpreted. However, some cases show abnormal signal patterns leading to equivocal and challenging interpretation. The incidence of these abnormal patterns is largely unknown. Using a retrospective cohort we explored the incidence of abnormal signal patterns across common bone and soft tissue tumour types to raise awareness of this occurrence and to aid in the interpretation. In total, 1,087 bone and soft tissue tumours tested by break-apart probes were examined. The abnormal signal patterns were classified as deletion, additional copy and amplification, which were found at highest frequency in low-grade fibromyxoid sarcoma (32%, 6/19), and at moderate frequencies in those from alveolar rhabdomyosarcoma (10%, 9/94), nodular fasciitis (9%, 18/209), synovial sarcoma (8%, 17/207) and Ewing sarcoma/round cell sarcoma with EWSR1-non-ETS fusions (6%, 29/497). The lowest frequency was found in clear cell sarcoma (1%, 1/61). Despite the equivocal results from the abnormal signal patterns, the specific fusion genes were confirmed by orthogonal molecular techniques such as FISH with fusion probes, RT-PCR or next-generation sequencing.

To review the spectrum of clinical and imaging features of nodular fasciitis, emphasizing those most characteristic of this diagnosis. A retrospective review of our institutional pathology and imaging databases from 2006 to 2024 identified 89 patients with confirmed nodular fasciitis pathology and imaging evaluation. For the purpose of analysis, lesions were subdivided into 2 basic groups: superficial and deep. Superficial lesions were defined as those involving the skin, superficial fascia, subcutaneous fat, and/or extending to thedeep fascia. Deep lesions were defined as those localized to the deep fascia or extending deep to the deep fascia, as well as those that were intermuscular or intramuscular. There were 45 females and 44 males with an overall average age of 37.3years (range 1.5-84years; 68.5% between 20 and 60years). There were 30 superficial lesions (33.7%) and 59 (66.3%) deep lesions. Deep lesions were on average 65% larger than those located superficially and patients with deep lesions were on average 7.2years older than those with superficial lesions. While there are no pathognomonic imaging features, careful attention to the relationship of the lesion to the adjacent fascia, as well as to the identification of characteristic time-dependent lesional MR signal changes can be useful aids in identifying this lesion. While nodular fasciitis is often considered to be an uncommon soft tissue tumor, it is recognized as the third most common benign soft tissue lesion. Knowledge of the spectrum of lesion characteristic locations and appearances will facilitate definitive diagnosis.

This study aimed to determine the characteristic clinical and magnetic resonance imaging (MRI) findings that can distinguish nodular fasciitis (NF) from myxofibrosarcoma (MFS) because they are sometimes difficult to differentiate due to the overlapping imaging findings, such as the "fascial tail" sign. Thirty patients with NF and 44 with MFS were included in this study. The following MRI features were evaluated: mass size, anatomical and compartmental location, presence and type of pseudo-capsule, degree of heterogeneity, presence, and length of the "fascial tail" sign, and presence of peritumoral edema. Using diffusion-weighted images (DWI), we determined the presence of diffusion restriction and measured the apparent diffusion coefficient (ADC) values. On dynamic contrast-enhanced (DCE) images, we obtained the values of Ktrans, Kep, Ve, iAUC, and time-concentration curves using Tissue 4D. The patients with NF were significantly younger than those with MFS. The average sizes of MFS and NF were 6.27±3.74 and 3.03±1.81cm, respectively. Linear logistic regression analysis revealed that age, recurrence, "fascial tail" length, peritumoral edema, enhancement heterogeneity, and Ve differed significantly between the NF and MFS groups. The length of "fascial tail," contrast heterogeneity, and compartmental location were statistically significant factors influencing the recurrence. Older age (above 46y), larger tumor size (>4cm), peritumoral edema, enhancement heterogeneity, and longer "fascial tail" (>25mm) are more frequently associated with MFS, while the functional MR imaging findings, except the Ve value (>0.417), showed no significant differences.

Genetic landscapes of breast tumors by next-generation sequencing with focus on less common types and genotype-phenotype correlations.

11547 Background: Recently, first-in-class FDA approval was granted in the U.S. for use of the gamma secretase inhibitor (GSI), nirogacestat, for adults with progressive desmoid fibromatosis. In tandem, the unpredictable clinical behavior of desmoids, which ranges from local aggression to regression, raises consideration of whether diagnostic and molecular variability underlie their varying biological potential. With an aim to understand both, and to explore the potential for biomarkers for GSI therapy selection, prediction, and prognosis, we performed a retrospective review of comprehensive genomic profiling and histology of desmoids and other soft tissue tumors harboring CTNNB1 or APC mutations. Methods: Using real-world reference laboratory database of tumors submitted for clinical genomic assessment (Caris Life Sciences), we queried for samples with a diagnosis of desmoid fibromatosis, or for other neoplasms of soft tissue origin harboring CTNNB1 or APC mutations. Samples underwent next-gen sequencing of (whole exome) to identify gene variants/copy number alterations and of RNA (whole transcriptome) for expression and fusion profiling. Findings were correlated with available clinical data and whole slide image histologic review. Results: We identified 74 tumors submitted as desmoid fibromatosis, of which 80% harbored CTNNB1 and 15% harbored APC pathogenic or likely pathogenic variants. CTNNB1 variants included codon 41 (58%), codon 45 (41%), and ubiquitin motif codon 36 (1%), while 91% of APC variants detected were in exon 16. Recurrent co-alterations were rare, involving MUTYH (heterozygous G396D) in 2 samples, and TMB-High (≥10 mutations/Mb) present in 3 . Notably, 4 “desmoids” (5%) lacked characteristic mutations, one of which harbored COL1A1::USP6 fusion, reclassified as nodular fasciitis. Among 76 soft tissue tumors diagnosed as other entities at analysis but found to harbor CTNNB1/APC mutations, 6 (all limited core biopsies), could be confidently reclassified as desmoids. The remaining 70 CTNNB1/APC mutant neoplasms were diverse, including synovial sarcoma (11%) and rhabdomyosarcoma (10%). Conclusions: Correlation of genomics and histopathology may allow identification of other tumor types misclassified as desmoid fibromatosis. Conversely, genomic correlation facilitated recognition of additional desmoids among tumors submitted with other diagnoses. The striking lack of secondary mutations seen in this large cohort with comprehensive DNA sequencing implies that other mechanisms explain and could predict their variable behavior, for which we are exploring paired transcriptome profiling data. Finally, subsets of diverse, other soft tissue neoplasms harbor CTNNB1 or APC mutations, which may have implications for the design of future biomarker-selected Phase II basket trials.

A case of nodular fasciitis that appeared in the breast and required differentiation from a malignant tumor.

Nodular fasciitis in the zygomatic region: case report

Facial nodular fasciitis in an adult patient: a case report of an uncommon manifestation

The diagnostic utility of SOX11 Immunohistochemical expression in malignant peripheral nerve sheath tumors and their potential mimickers.

ABSTRACTBackgroudNodular fasciitis is a benign proliferative spindle‐cell lesion that presents itself as a rapidly growing mass arising from the subcutaneous fascia; given these characteristics, it is often put in the differential diagnosis with sarcomatous lesions. Nodular fasciitis commonly presents in individuals in their third to fifth decades of life with no definite gender predilection. They are frequently located on the extremities and the trunk and infrequently in the head and neck region. Lesions in the orofacial region are very uncommon.Material and MethodsWe describe an interesting case of nodular fasciitis in a 33‐year‐old patient who presented with a significant increase in size in a few weeks, located in an infrequent site for this pathology, such as the masticatory space.ConclusionsThe purpose of this work is to describe the correct sequence of procedures to recognise these lesions at the level of less frequent sites, excluding malignant neoplasms such as sarcomas, and plan the best therapeutic option.

47 USP6 RNA Chromogenic In Situ Hybridization is Useful in the Diagnosis of Nodular Fasciitis and Aneurysmal Bone Cyst