Intraarticular Nodular Fasciitis

Epidemiology

Intra-articular nodular fasciitis may occur in children or adults.

Clinical features

Patients may present with joint pain or a palpable mass, often of a number of months duration. Various joints may be involved1,2.

Macroscopic appearances

Lesions are circumscribed but not encapsulated. They appear tan or yellow.

Histopathology

The features are those typical of subcutaneous nodular fasciitis, with loose myxoid to collagenous stroma, extravasated red cells, and a mild lymphocytic infiltrate. There may be marked stromal collagenisation, which may resemble keloid. Prominent haemosiderin deposition is a feature of intra-articular nodular fasciitis.

Immunohistochemistry

	SMA	6/61
	Desmin	1/61
	Caldesmon	0/61
	S-100	0/61
	b-catenin	0/61

Differential diagnosis

The clinical differential diagnosis may include:

Giant cell tumour of tendon sheath
Pigmented villonodular synovitis
synovial chondromatosis
Inflammatory arthritis

The histological differential may include:

Fibroma of tendon sheath: almost always arises in the hand. There are peripheral slit-like vessels.
Giant cell tumor of tendon sheath
Desmoid fibromatosis: fascicles are long and sweeping. There is nuclear positivity for b-catenin.
Juxta-articular myxoma: almost always involves the knee.
Low-grade fibromyxoid sarcoma

Management

Excision

Prognosis

Excision appears to be curative.

References

1 Hornick JL,Fletcher CD Intraarticular nodular fasciitis--a rare lesion: clinicopathologic analysis of a series. Am J Surg Pathol 2006; 30:237-41

2 Yamamoto T, Nagira K, Noda M, et al. Intra-articular nodular fasciitis. Arthroscopy 2001; 17:E38