INTRODUCTION

CASE REPORT

CONCLUSIONS

A 47-year-old male presented to the ENT clinic at Shands at the University of

Florida in December of 2009 with a mass of the left masseter. Imaging ordered by

his community otolaryngologist was concerning for sarcoma versus hemangioma.

Upon further questioning, he reported prior trauma to the region as he had been hit

by a car glass window approximately 5 months earlier. He initially had pain and

trismus but this resolved, and at presentation he only noted an asymptomatic small

firm mass that was palpable intraorally on self examination. His past medical history

was noncontributory.

Physical examination revealed a firm, nontender, immobile mass over the left

masseter muscle that measured 3 cm x 2 cm. He subsequently underwent a core

biopsy. Final pathology results were consistent with nodular fasciitis.

The patient’s postoperative course was uneventful and a one-month follow-up

showed that his mass lesion was nearly imperceptible. Once given the diagnosis of

benign nodular fasciitis, the patient chose clinical observation rather than further

surgery for complete excision.

SUMMARY

Contact Information: debbie.joseph@ent.ufl.edu

PATHOLOGY

Fig . 2 Fig . 3

NF is an uncommon benign proliferation of fibrous tissue. It should be

considered on the differential of masses of the head and neck and be distinguished

from a malignant process.

REFERENCES

The World Health Organization defines nodular fasciitis (NF) as a benign

and reactive fibroblastic growth extending from the superficial fascia into the

subcutaneous tissue or muscle.1 NF is a rare, idiopathic spindle-cell lesion that

more commonly occurs in the upper and lower extremities and more rarely is

seen in the head and neck. It is thought to be an reactive inflammatory process

from prior trauma.

Nodular fasciitis may be mistaken for more serious tumors such as

sarcoma both on imaging and histology. In fact, when first described by

Konwaler et al in 1955, it was referred to as pseudosarcomatous fasciitis.2 It has

also been referred to as psuedosarcomatous fibrosis and infiltrative fasciitis.

Treatment of choice is often complete surgical removal.3 We present a

case of nodular fasciitis of the masseter muscle that underwent core biopsy that

regressed spontaneously.

T1 -weighted axial and T2-

weighted coronal images

of left massester nodular

fasciitis

NF is a rare diagnosis and only 7-20% are found in the head and neck region.4

These lesions rarely recur, do not develop metastases, and are readily cured by local

excision.5 However, the lesion is often self-limiting. Yanagisawa et al. report a case of

nodular fasciitis of the cheek that spontaneously regressed after biopsy.6 The authors

concluded that NF regressed after transformation into a fibrous lesion following biopsy.

The pathogenesis of NF is not known. It is believed that local injury or a local

inflammatory process may trigger the myofibroblastic proliferation. However, a history of

preceding trauma can be obtained from less than 15% of patients.7

MRI and computed tomography may be used in the initial evaluation of nodular

fasciitis, but the findings are nonspecific. Radiographically the lesion typically is round

and discrete but may extend past fasical planes and have atypical borders. Histologic

analysis is required but too may be confusing. As with malignancy as it can exhibit high

cellularity, focal nuclear atypia, and mitoses. However, nodular fasciitis spindle cells

contain vimentin, and smooth-muscle–specific actin. They do not contain desmin,

keritin, or S-100 protein, for which sarcoma spindle cells stain positive.8

Nodular Fasciitis of the Masseter Muscle Debbie E. Joseph MD1, John D. Reith MD2, Neil N. Chheda MD1

1Department of Otolaryngology, 2Department of Pathology University of Florida, Gainesville FL

Nodular fasciitis of the head and neck is a rare, benign, soft-

tissue tumor that can clinically and radiologically mimic more

serious processes such as sarcoma. A 47-year-old male presented

with a palpable lesion in the upper left buccal region.

Radiographically, an invasive process of the masseter muscle

could not be excluded. Biopsy was performed. The mass was

diagnosed as nodular fasciitis of the left masseter. The imaging and

histological findings of this case are presented to highlight the

importance of including this diagnosis in the differential of head

and neck masses.

IMAGING

DISCUSSION

1. Robertson B, Roche WC, Shabb B. Nodular fasciitis: a case report. J Oral Maxillofac Surg. 1986;44(3):236– 9

2. Konwaler BE, Keasbey L, Kaplan L: Subcutaneous pseudosarcomatous fibromatosis (fasciitis). Am J Clin Pathol 25: 241e252, 1955

3. Martinez-Blanco M, Bag JV, Alba JR, Basterra J: Maxillofacial nodular fasciitis: a report of 3 cases. J Oral Maxillofac Surg 60: 1211e1214, 2002

4. Kijima H, Okada K, Ito H, Shimada Y, Nanjo H, Itoi E. Nodular fasciitis of the finger. Skeletal Radiol 2005;34:121-3

5. Lenyoun EH, Wu JK, Ebert B, Lieberman B: Rapidly growing nodular fasciitis in the cheek of an infant: case report of a rare presentation. Eplasty 8: 296e301, 2008

6. Yanagisawa A, Okada H: Nodular fasciitis with degeneration and regression. J Craniofac Surg 19: 1167e1170, 2008

7. Haddad AJ, Avon SL, Clokie CM, Sandor GK: Nodular fasciitis in the oral cavity. J Can Dent Assoc 67: 664e667, 2001

8. Montgomery EA, Meis JM. Nodular fasciitis. Its morphologic spectrum and immunohistochemical profile. Am J Surg Pathol. 1991;15(10):942–8

Low magnification photomicrograph showing the typical histologic features

of nodular fasciitis, including haphazardly arranged spindled cells with

small foci of keloidal collagen, scattered chronic inflammatory cells, and

extravasated erythrocytes (hematoxylin and eosin stain, original

magnification x 100).