Intraneural nodular fasciitis of the median nerve: case report and literature review

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.

Intraneural Nodular Fasciitis of the Femoral Nerve with A Unique CTNNB1::USP6 Gene Fusion: Apropos of a Case and Review of Literature

Nodular fasciitis (NF) is a benign proliferation of fibroblasts and myofibroblasts occurring most commonly in the upper extremities that can mimic a variety of mesenchymal tumors including sarcoma. Although reported in almost all anatomic locations, only 7 cases of intraneural nodular fasciitis have been reported in English literature. The CTNNB1::USP6 gene fusion has not been previously reported in intraneural nodular fasciitis, although it has been reported in three entities including aneurysmal bone cyst, nodular fasciitis, and intravascular fasciitis. We report a case of a 29-year-old female with a 6-month history of left leg weakness, myalgia, and paresthesia of the left foot prompting a clinical diagnosis of a peripheral nerve sheath tumor. Surgical resection was performed, and histologic sections revealed a circumscribed lesion composed of banal spindle cells with variable interstitial collagen and occasional mitotic figures. By immunohistochemistry, the lesional cells were positive for smooth muscle actin, smooth muscle heavy chain myosin, p16, and H-caldesmon and negative for desmin, S-100, SOX10, HMB45, CD34, and beta-catenin. Fluorescence in Situ Hybridization for USP6 gene rearrangement was positive and consistent with the diagnosis of nodular fasciitis. Next-generation sequencing uncovered the presence of a CTNNB1::USP6 gene fusion involving CTNNB1 gene in exon 1 at the genomic position chr3:41241161 and the USP6 gene in exon 1 at the genomic position chr17:5033231. This gene fusion was confirmed by Sanger sequencing. Herein, we report a case that underscores the rare incidence of intraneural nodular fasciitis and highlights the pitfalls associated with the clinical differential diagnoses of intraneural tumors.

Unilateral carpal tunnel syndrome: an unusual presentation of nodular fasciitis

Nodular fasciitis is a benign, self-limiting proliferative disorder of fibroblast of uncertain aetiology, occurs frequently in the forearm. Nodular fasciitis in hand inducing carpal tunnel syndrome is exceptional. There are four cases of non-intraneural nodular fasciitis causing peripheral neuropathy that has been reported previously. We present the case of a 38-year-old man with features of unilateral carpal tunnel syndrome. Decompression of the median nerve performed subsequently along with excision of the lesion in a piecemeal fashion. Histopathological and immunohistochemical findings were consistent with nodular fasciitis. There were complete resolution of symptoms and no sign of recurrence at the end of 1 year after surgery.

Nodular fasciitis involving the palm

Nodular fasciitis (NF) is a self-limiting fibrous neoplasm that can be mistaken for a soft tissue sarcoma. It is characterised by rapid growth, slight pain and local tenderness. Although it is frequently found in the forearm, a lesion distal to the wrist is quite rare. We present two unusual cases of NF involving the palm, supported by detecting ubiquitin specific protease 6 gene rearrangement. The first patient had non-intraneural NF presenting as peripheral neuropathy affecting the digital nerve while the second patient suffered from painless, non-tender NF in the palm, which had not regressed spontaneously during the five months prior to surgery.

Intraneural Nodular Fasciitis in a Child: A Case Report and Review of the Literature

We present the case of an 11-year-old boy with intraneural nodular fasciitis of the median nerve at the distal part of the carpal tunnel. Complete excision of the involved median nerve and cable grafting using 4 fascicular segments of the sural nerve was performed for persistent pain and numbness after initial resection of the tumor in piecemeal fashion. Pain and numbness were completely resolved and there was no evidence of recurrence 24 months after the final surgery.

Intraneural nodular fasciitis of the radial nerve with rapidly progressive motor symptoms

Background:

Nodular fasciitis is a benign mesenchymal tumor arising from fascia that typically presents as a rapidly growing, subcutaneous mass. Intraneural cases are very rare and can present with neurological symptoms, requiring surgical resection.

Case Description:

A 31-year-old woman presented to us with painful paresthesias in her elbow and progressive motor deficits, for which she underwent surgery.

Conclusion:

The authors report the first case of intraneural nodular fasciitis occurring in the radial nerve and highlight the possibility of rapidly progressive motor deficit in patients presenting with this rare clinical entity.

Secondary aneurysmal bone cyst in the distal humerus after resection of intra-articular nodular fasciitis of the elbow

Background

Nodular fasciitis most often occurs within subcutaneous tissues, but may also arise within skeletal muscle, dermis, vessels, peripheral nerves and, although rarely, within joints. Knowledge regarding the cause of aneurysmal bone cysts, its natural history, and the results of treatment is limited. Secondary aneurysmal bone cysts are associated with other neoplastic processes. Intra-articular nodular fasciitis in the elbow joint has not been reported previously, nor has the development of aneurysmal bone cyst secondary to intra-articular nodular fasciitis in the elbow joint.

Case presentation

We report an unusual case of a Japanese 13-year-old boy who presented with a 1-year history of right elbow pain. The onset of pain was insidious, without antecedent trauma. On physical examination, the range of motion of the elbow was limited. Grip strength was reduced in the affected extremity. Incisional biopsy was performed and histologic findings revealed nodular fasciitis in the elbow joint. After tumor excision, a secondary aneurysmal bone cyst in the distal humerus developed. Endoscopy-assisted curettage and artificial bone grafting were performed. One year after surgery, a plain radiography showed no recurrence, and the patient returned to his daily activities without any symptoms.

Conclusion

An aneurysmal bone cyst in the distal humerus developed after excision of intra-articular nodular fasciitis arising in the elbow. The secondary aneurysmal bone cyst successfully healed after endoscopy-assisted curettage and artificial bone grafting. The findings of this case suggest that these two tumors reside in the same biologic spectrum defined as USP6-induced tumors.

MRI characteristics of nodular fasciitis of the musculoskeletal system

OBJECTIVE

To evaluate MRI imaging appearances of nodular fasciitis in a pathologic-proven series of 29 patients.

MATERIALS AND METHODS

Review of the orthopedic oncology and pathology databases yielded 51 cases of histologically proven nodular fasciitis. MR imaging was available in 29 patients. Three musculoskeletal radiologists retrospectively reviewed all cases in consensus. Imaging features evaluated included location in the body, size, compartmental localization, relationship to fascia, signal characteristics, enhancement pattern, transcompartmental extension, and osseous and intra-articular involvement.

RESULTS

There were 15 male and 14 female patients. Mean age was 33 years (range, 16-59 years). Lesions ranged in size from 1.6 to 9 cm with 84 % of lesions measuring less than 4 cm. Twenty-three lesions were located in the upper arm or shoulder girdle. Nine lesions were subcutaneous in location, nine were intra-muscular, and 11 were inter-muscular. Lesions were consistently ovoid in shape with broad fascial contact. They exhibited internal homogenous low T1 and heterogeneous intermediate T2 signal with surrounding edema and slightly inhomogeneous enhancement. Twelve lesions exhibited central non-enhancing areas. Trans-compartmental spread was demonstrated in nine lesions. Osseous changes were seen in five cases and included extrinsic cortical saucerization, medullary edema, and transcortical osseous invasion. Two lesions demonstrated intra-articular extension.

CONCLUSIONS

MR imaging features of nodular fasciitis are generally non-specific and can be mistaken for a soft tissue sarcoma. This series, the largest MRI series of musculoskeletal cases in the literature, confirms the predilection of nodular fasciitis for the upper extremity in young adults but also demonstrates that aggressive imaging features such as transcompartmental spread, and osseous and intra-articular involvement may be seen in association with this benign soft tissue lesion.