Spontaneous regression and recurrence in a case of nodular fasciitis

Clinical characteristics of nodular fasciitis of the ear in children

The rate of early misdiagnosis in patients with nodular fasciitis of the ear is high. To provide a basis for clinical diagnosis and treatment, we aimed to summarise the clinical manifestations, imaging results, pathological findings, treatment strategies, and postoperative follow-up results for three cases of paediatric nodular fasciitis (two girls, one boy) treated in the Department of Otorhinolaryngology, Head and Neck Surgery, at Beijing Children's Hospital of Capital Medical University from 2018 to 2020. The average age at diagnosis was 24 months. Lesions occurred in the left ear in two cases and right ear in one case. All patients had a history of biopsy before surgery. Rapid growth was observed following biopsy in two patients, and anti-inflammatory treatment was ineffective in all three cases. Fluorescence in situ hybridisation analysis of ubiquitin-specific peptidase 6 (USP6) was performed in two of the three cases, with positive results. The lesions exhibited hypo-intensity or iso-intensity on T1-weighted magnetic resonance imaging (MRI) and heterogeneous hyper-intensity on T2-weighted MRI. "Fascial tail" signs were observed on imaging in all cases. Surgical resection was performed in all cases. Intact ear appearance was observed at follow-up, and there were no cases of recurrence.Conclusion: Combining clinical features with imaging findings may improve the accuracy of preoperative diagnosis in patients with nodular fasciitis. In addition to pathological findings, genetic testing for USP6 may aid in diagnosis. The final diagnosis should be based on comprehensive assessment. Complete surgical resection can prevent recurrence. What is Known: • Paediatric NF around the ear is rare and is easily misdiagnosed as other inflammatory masses that have a higher incidence in children. • Most previous reports of NF were case reports. What is New: • Combining clinical and imaging findings with genetic testing for USP6 rearrangement may improve the accuracy of preoperative diagnosis in patients with NF. Nonetheless, the final diagnosis should be based on comprehensive assessment. • The present paper is significant in that it represents the only report of three cases of ear NF in children with a complete medical history and prognosis.

Simultaneous bifocal and asymptomatic intramuscular nodular fasciitis of the thigh: A case report

Nodular fasciitis (NF) is a rapid-growth benign that is misdiagnosed as sarcoma and leads to overtreatment. The spontaneous regression of NF is a possible phenomenon. "Wait and see" ideal is one of the treatment strategies of NF.

USP6 Gene Rearrangement by FISH Analysis in Cranial Fasciitis: A Report of Three Cases

Cranial fasciitis (CF) is an uncommon benign myofibroblastic proliferation involving the soft and hard tissues of the cranium. It typically occurs in the pediatric population with a male predilection (male-to-female ratio 1.5:1). The clinical presentation is usually a rapidly expanding, painless nodule. Bone erosion may be appreciated radiographically. Histopathologic sections of CF show plump, fibroblast-like cells with pale, oval shaped nuclei and prominent nucleoli in a fibrous or myxoid background. Growth is self-limited and surgical excision is considered curative. Due to these features, CF is thought to be a variant of nodular fasciitis (NF). As with NF, CF may mimic a sarcomatous process and pose a diagnostic challenge to clinicians and pathologists alike. Erickson-Johnson et al. identified rearrangements of the ubiquitin-specific protease 6 (USP6) gene in 44 of 48 cases of NF. MYH9 was the fusion partner in 12 of these cases. To date, the molecular profile of CF has not been studied. Here we present the molecular findings in three cases of CF identified at our institution. Each case was subjected to fluorescence in-situ hybridization with appropriate negative controls. Two of three cases were positive for the USP6 gene rearrangement. The third case failed to hybridize, likely related to nucleic acid damage secondary to decalcification. Negative controls did not demonstrate the genetic rearrangement. These findings warrant further investigation of the USP6 gene rearrangement in CF, as it may prove helpful as a diagnostic adjunct in challenging cases.

Nodular fasciitis in the buccal region with rapid growth after incisional biopsy mimicking sarcoma

Nodular fasciitis (NF) is a reactive and proliferative fibroblastic lesion that occurs predominantly in the upper limbs but rarely develops in the oral cavity. This lesion can be misdiagnosed as malignant owing to its frequent display of rapid growth, rich cellularity, and high mitotic activity. Unlike a sarcoma, NF can resolve spontaneously or after an incisional biopsy. We describe a challenging case involving a lesion in the buccal region that rapidly enlarged after incisional biopsy. This variation of clinical behavior illustrates the difficulty in predicting whether NF will continue to grow or regress. Clinicians dealing with cases of an enlarging fibrous lesion of short duration should remain aware of this disease entity and its potential diagnostic dilemma.

USP6-induced neoplasms: the biologic spectrum of aneurysmal bone cyst and nodular fasciitis

USP6 (also known as TRE17) is a ubiquitin-specific protease that was identified as an oncogene in transfection experiments with Ewing sarcoma DNA 2 decades ago. Until recently, little was known about USP6 function and mechanisms of oncogenic activation. The identification of USP6 fusion genes in aneurysmal bone cyst (ABC) and, more recently, in nodular fasciitis led to a better understanding of the pathogenesis of these lesions. Furthermore, the detection of USP6 genomic rearrangements or USP6 fusion genes may be used as a diagnostic tool for these lesions. In this review, we discuss the clinicopathologic features, molecular pathology, and pathogenesis of ABC and nodular fasciitis. We also discuss the possible line of differentiation of ABC and its relationship to nodular fasciitis and other lesions.

Nodular fasciitis of the oral cavity with partial spontaneous regression (nodular fasciitis)

Nodular fasciitis is a lesion found in the subcutaneous fascia that micoscopically presents as a benign proliferation of fibroblasts and myofibroblasts, which may be mistaken for a sarcoma due to clinically rapid growth. Diagnosis is by histopathology and of the immunohistochemical profile. We describe a case of nodular fasciitis in the oral cavity that demonstrated partial spontaneous regression. The patient was a 32-year-old man with a buccal mucosal mass, which had grown rapidly for 45 days. On microscopic examination, the lesion displayed a well-delineated but not encapsulated proliferation of spindle cells, with a nodular growth pattern. Immunohistochemical analysis showed positivity of the spindle cells for the antibodies against smooth muscle actin and muscle-specific actin (HHF-35). Treatment of such lesions typically involves complete conservative excision, but the lesion may regress eventually in the absence of definitive treatment.