Nodular fasciitis of the external auditory canal: Clinical case report and review of the literature

Nodular fasciitis is a benign reactive soft tissue tumor arising from fibroblasts and myofibroblasts.Its incidence is low and misdiagnosis is frequent especially for malignant lesions.This can lead to inappropriate and unnecessary invasive treatment.Nodular fasciitis of the external auditory canal is extremely rare.So far,around fifteen cases have been reported.We present here the case of a 90-year-old patient with nodular fasciitis of the right external auditory canal.The lesion extends anteriorly for 6.5 cm and reaches the posterior wall of the maxillary sinus.To our knowledge,this is the first case in the literature of an external auditory canal nodular fasciitis presenting as an inflammatory ear polyp with such a wide extension.

Occipital nodular fasciitis easily misdiagnosed as neoplastic lesions:A rare case report

BACKGROUND Nodular fasciitis(NF)is a benign disease originating from fascial tissue and most commonly occurs in the extremities,followed by the trunk,head,and neck.NF of the head and neck occurs mainly in the face and neck,and it has not been reported in the occipital region.CASE SUMMARY A 30-year-old man was admitted because of a mass in the left occipital region.Imaging examination revealed a soft tissue nodule in the left occipital area.An enhanced magnetic resonance imaging scan showed characteristic inverted target and fascial tail signs.Histopathological analysis showed a large amount of spindle cell proliferation,and immunohistochemistry showed positive expression of SMA in the spindle cells in the lesion.Finally,nodular fasciitis was diagnosed.CONCLUSION NF of the head and neck is rare,but the possibility of NF should be considered when nodules or masses with rapid subcutaneous growth are found and tenderness in the head and neck is present.Imaging examination,in combination with clinical manifestations and histopathological examination,can improve the diagnostic accuracy for the disease.After diagnosis,local surgical resection is the first choice of treatment.

Giant nodular fasciitis originating from the humeral periosteum:A case report

BACKGROUND Nodular fasciitis(NF)is a self-limiting tumor that mostly occurs in the subcutaneous superficial fascia.NF originating from the appendicular periosteum is extremely rare.A large NF lesion of periosteal origin can be misdiagnosed as a malignant bone tumor and may cause overtreatment.CASE SUMMARY A right axillary mass was found in a 46-year-old man and was initially diagnosed intraoperatively as low-grade sarcoma,but later diagnosed as NF after postresection histopathological evaluation.Furthermore,fluorescence in situ hybridization analysis revealed a USP6 gene rearrangement that confirmed the diagnosis.To the best of our knowledge,this is the first case of NF in the humeral periosteum.CONCLUSION NF poses a diagnostic challenge as it is often mistaken for sarcoma.Postoperative histopathological examination of whole sections can be combined with immunohistochemical staining and,if necessary,the diagnosis can be confirmed by molecular detection,and thus help avoid overtreatment.

Intraarticular Nodular Fasciitis in the Knee Joint with <i>USP6</i>-Gene Rearrangement<br/>—A Case Report with Special Attention to Diagnostics of Intraarticular Lesions

Background: Nodular fasciitis (NF) is currently considered a self-limited clonal neoplastic process. It shares the rearrangement of USP6-gene with aneurysmal bone cysts and myositis ossificans. The presented case is of interest as this is a rare site of presentation of NF;so far only few single cases of intraarticular NF have been reported with documented USP6-gene rearrangement. Intraarticular neoplasias of the knee joint are rare;the most frequent being tenosynovial giant cell tumor (TSGCT). Given a nationwide annual incidence rate of 14 for the lower extremity and about 75% affecting the knee joint about 10 new cases involving the knee joint can be expected per 1 million persons/year. All other types of benign neoplasms are comparably rare while malignant intraarticular processes are extremely rare with most of them reported as single case studies. Aim: We report our case to emphasize the importance of preoperative diagnostics including the option of biopsy. Intraarticular malignant processes are extremely rare and frequently are operated on accidently with negative consequences for the patient. Tactics and techniques to treat benign processes depend on the correct pathologic diagnosis. Case presentation: The 38 year old man noticed slowly increasing swelling of his left knee joint after wakeboarding. Because of continuing discomfort 2 months later MRI diagnostic revealed, apart from retropatellar cartilage lesions, a popliteal mass compatible with a Baker cyst. The lesion of interest (later diagnosed as NF) was neither recognized by the radiologist nor the treating clinician. During the following 8 months the patient felt increasing swelling of the knee joint. The repeat MRI documented the crescent intraarticular solid synovial mass in the medial patellofemoral recess without signs of hemosiderin impregnation. A percutaneous sonographically guided 16G needle biopsy was performed. Histologically, bland myofibroblastic proliferation suggestive of nodular fasciitis (NF) was found. The next generation sequencing (NGS) demonstrated the presence of MYH9-USP6 gene fusion, confirming the diagnosis of NF. The lesion was excised under arthroscopic control. At 1 year follow-up the patient is asymptomatic. Conclusion: The case is of interest because of its rare pathology. The decision how to treat was based on pathologic biopsy diagnostics including the USP6-gene rearrangement. In view of similar presentation of the rare malignancies we also want to stress the importance of definitive diagnostics which generally are possible only through biopsy.

Fine Needle Aspiration Cytology of Pseudosarcomatous Reactive Proliferative Lesions of Soft Tissue

Objective:Nodular fasciitis(NF),proliferative fasciitis(PF)and proliferative myositis(PM)are the most common pseudosarcomatous reactive proliferative lesions of soft tissue.These lesions often resolve spontaneously.The aims of this study were to summarize the diagnostic features of fine needle aspiration cytology(FNAC)of pseudosarcomatous reactive proliferative lesions of soft tissue and to establish the criteria in differentiating these lesions from true sarcoma,thus allowing conservative management.Methods:FNAC of 17 cases(13 NF,2 PF,2 PM),from 1994 to 2001,were reviewed in correlation with the clinical course or results of biopsy.Results:The FNAC features of pseudosarcomatous reactive proliferative soft tissue lesions were characterized by a pleomorphic pattern of the proliferative cells and the presence of ganglion-cell-like cells.The proliferative cells varied widely from spindle shaped with long cytoplasmic processes to more plump cells with round to oval nuclei.In spite of the large nuclei and prominent nucleoli in ganglion-cell-like cells,the nuclei were cytologically benign with thin and smooth nuclear membranes and fine chromatin.Clinically,all lesions appeared as small,superficially located,rapidly growing nodules with short duration of symptoms.Ten cases of NF,one case of PF and two cases of PM showed spontaneous resolution in 1-12 weeks(mean 4.7 weeks)following diagnosis by FNAC.All patients were clinically well and devoid of any symptoms or signs of recurrence or metastasis in a follow-up period of 1-64 months after FNAC or biopsies.Conclusions:It is possible to differentiate pseudosarcomatous reactive proliferative soft tissue lesions from true sarcoma based on cytological criteria in FNAC together with clinical correlation.All such lesions diagnosed by FNAC should be managed non-surgically first,with follow-up.If regression does not occur within 4 to 8 weeks,surgery should then be performed.