Introduction

Definition of nodular fasciitis

Fascia can be described as a connective tissue found around every organ, bone, muscle, nerve, and blood vessel.¹ Nodular fasciitis is a non-cancerous tumour that forms in the fascia.¹

Nodular fasciitis can present very similarly to cancerous soft tissue tumours called sarcomas, and may feel scary to patients. It is essential to remember that while nodular fasciitis is a tumour, it is not cancer,¹ and often resolves itself without treatment.¹ This article provides an in-depth examination of the presentation and symptoms of nodular fasciitis.

Epidemiology 

Nodular fasciitis is the most common fibrous soft tissue lesion.¹¹

Common age groups affected

Nodular fasciitis commonly affects adults aged between 20-40.¹ However, toddlers and children can also have it.¹  

Sex distribution

No differences are seen in distribution between the two sexes.³

Etiology

Possible causes and risk factors

The exact pathogenesis of nodular fasciitis isn’t known, but tumours often result from a traumatic injury to the affected area.⁵

A possible cause of nodular fasciitis may be inflammation in fibrous connective tissue.⁵

Genetic considerations

Nodular fasciitis is a result of a genetic mutation that happens in the cells of the tumour. The mutation causes a genetic rearrangement of the MYH9 and _USP6_ genes.¹

Pathophysiology

Histopathological characteristics

The characteristics of nodular fasciitis can be similar to those of a tumour. Nodular fasciitis tumours grow fast and contain a large number of cells.² They also show high mitotic activity, meaning cells are dividing fast and irregularly around the border of the tumour.²

Common locations in the body

The tumours can be found anywhere in the body, but commonly appear in the limbs or the trunk and less commonly in the head and neck.² It can occur in the head and neck in infants or children.⁴ The upper limbs, especially the forearms, are the most common site for the tumour.⁴

Clinical presentation

Onset and progression

The tumours tend to grow fast, and concerned patients usually visit a doctor within the first few weeks.⁵ Many studies have found the time from the first detection of nodular fasciitis to surgical treatment to be under 2 months.⁵

Physical characteristics of the lesion

The characteristics of nodular fasciitis aren’t unique enough from other tumours to be able to use them for differentiation.⁵

Size and texture

Nodular fasciitis tumours are usually small, around 2-3 cm in size.⁴ However, the tumours can grow fast, and some individuals may have tumours up to 12 cm in size.¹

Shape and surface features

The tumours are usually oval or round, and grey-white in colour, with a slimy texture.⁵

Mobility and attachment to surrounding tissues

The tumours can occur both close to the surface of the skin or deeper in the body,⁴ however, most occur superficially.⁵

Symptoms

The main symptom of nodular fasciitis is a lump that is felt when pressing down on the skin.¹ According to the Cleveland Clinic, the lump can be:

1. Firm
2. Rubbery
3. Hard

Pain and tenderness

The tumours are often painless to touch,⁴ however, pain or tenderness may be present in up to half of the patients.⁵  

Functional impairment depending on location

Tumours may compress nerves, which can lead to symptoms such as numbness in that area, temporary paralysis, or pins and needles.¹

Absence of systemic symptoms (e.g., fever, weight loss)

Unlike cancerous tumours, nodular fasciitis is not associated with systemic symptoms. This is a large difference between the two presentations.

If one notices any mass, it is important to get it checked out by a doctor. However, it is important to mention any body-wide symptoms the individual might have noticed.

Diagnostic evaluation

Clinical examination

The studies presenting cases often report a typical patient as having no symptoms other than a growing lump and associated pain.^6,7 Sometimes, no obvious link to a traumatic injury can be made, yet athletes may develop nodular fasciitis as a result of ongoing sports injuries.⁷

One case disappeared by itself, yet showed recurrence in the same spot after 4 years and was removed through excision because cancer could not be excluded as a potential diagnosis.⁶ When it isn’t clear whether a tumour is cancerous or not, a patient should be managed with the possibility of cancer.⁶

A general practitioner will usually refer you to an orthopaedist for further tests.

Imaging studies

Ultrasound characteristics

Nodular fasciitis can present on ultrasounds as an isoechoic lesion, meaning it shows the same brightness as its surrounding structure.⁸ It may also be hypoechoic, meaning it appears darker than the structures around it.⁸

MRI findings

Nodular fasciitis may present variably on MRIs, and this is due to the different categorisation of its contents. Tumours may be myxoid (made up of a clear, mucous substance), fibrous or cellular.⁸

Histology of nodular fasciitis

Nodular fasciitis often appears with short and irregular bundles and fascicles.¹¹ The cells have a dense reticulum structure.¹¹ They also have some mature collagen.¹¹

Differential diagnosis

Diagnoses have to differentiate between cancerous tumours, such as sarcomas, and other noncancerous soft tissue tumours, such as lipomas. Radiopaedia presents a list of potential differential diagnoses:

• Dupuytren disease
• Noncancerous soft tissue tumours:
  • Desmoid tumours outside the abdomen
  • Angiomatoid fibrous histiocytomas¹
• Soft tissue sarcoma
• Myositis ossificans¹
• Neurofibroma
• Schwannomas.¹

Histological examination

Biopsy techniques

Two types of biopsies can be used to differentiate between cancerous and noncancerous tumours. These include a needle biopsy, also known as fine needle aspiration, or an excisional biopsy.¹

Different types of nodular fasciitis

The Cleveland Clinic describes other presentations of nodular fasciitis that do not develop in the fascia. These include:

1. Deep fascial (in the rougher connective tissue deeper in the body)
2. Dermal (skin layer)
3. Inter or intra muscular (in between or inside muscles)
4. Intravascular

Treatment and management

Surgical intervention

Indications for surgery

Not all nodular fasciitis tumours require surgery. If tumours are small, they usually go away by themselves within 3 months; doctors may suggest monitoring them. Steroid injections can also be used to treat nodular fasciitis.¹

Surgery may be recommended if the lump has grown to be quite large or is causing pain or other symptoms, such as those associated with nerve compression.¹

For nodular fasciitis tumours occurring on the face, surgical treatment resulted in a higher recurrence rate and greater scarring compared to nonsurgical treatment.⁹ Therefore, if cancer is first excluded through histology, nonsurgical treatment can potentially be used as the treatment for nodular fasciitis tumours occurring on the face.⁹

Types of surgical procedures

Lesional excision cures nodular fasciitis.⁴

Surgery is often minor and does not require patients to stay in the hospital overnight.¹

Prognosis

Overall prognosis

Recurrence rates

Recurrence of nodular fasciitis tumours after surgery is very rare.⁴ Studies show that nodular fasciitis even rarely recurs after incomplete excision.¹⁰

Long-term outcomes

Nodular fasciitis will not cause serious harm or death. It will go away either on its own or through surgery.¹ The tumours will not change into cancer and do not increase the risk of patients developing cancer.¹

Conclusion

Nodular fasciitis is a rapidly growing, noncancerous tumour that forms in the soft, connective tissue called fascia, which surrounds every organ, bone, muscle, and blood vessel in the body. The clinical presentation of nodular fasciitis can be very similar to that of other noncancerous or cancerous soft tissue tumours. However, nodular fasciitis is not harmful and often goes away on its own. An individual must seek a doctor’s advice whenever they find any lump growing in a part of their body.

Although nodular fasciitis is harmless, it may present similarly to cancerous tumours. If nodular fasciitis grows large and causes pain or other symptoms, outpatient surgery may be used to treat it. Surgery does cure the tumours, and recurrence is rare. The tumours often appear in the limbs and trunk, especially the forearms. They may also appear in the head or neck of children. Nodular fasciitis may be caused by a genetic displacement or a traumatic injury to the area. Biopsies, ultrasounds, and MR imaging are useful tools to confirm the diagnosis.