Nodular fasciitis is a benign, reactive proliferation of fibroblasts in the subcutaneous tissues and commonly associated with the deep fascia. It is also known as subcutaneous pseudosarcomatous fibromatosis, or proliferative fasciitis.
A nodule is a palpable, solid lesion, 5 or 10 mm in diameter, that may or may not be elevated. Larger nodules (more than 20 mm) are classified as tumors.
Nodular fasciitis is a benign proliferation of fibroblasts and myofibroblasts in the subcutaneous tissues. The lesions are generally small and solitary, arising commonly in the upper extremities of adults and in the head and neck region of infants and children. A history of trauma may precede these reactive lesions, but their cause is unknown.
Physicians are often called upon to do excisional biopsies in the diagnosis of subcutaneous tumors. Benign fibrous tumors represent a group of clinical entities that are often difficult to diagnose. Nodular fasciitis is one such benign fibroblastic proliferation whose rapid growth and rich cellularity frequently cause the lesion to be misdiagnosed as sarcoma.
Nodular fasciitis was first described by Konwaler in 1955 and was termed pseudosarcomatous fibromatosis. Other terms, such as pseudosarcomatous fasciitis, infiltrative fasciitis, and proliferative fasciitis, have also been used synonymously.
Nodular fasciitis is most commonly seen in young adults between 30 and 40 years of age. Approximately 10 percent of the lesions occur in children. Men and women appear equally affected, although in childhood the lesions may occur predominantly in boys.
The cause of nodular fasciitis is unknown, but it believed that the fibroblastic and myofibroblastic proliferation may be triggered by local injury or a local inflammatory process.
Most patients with this reactive proliferation have a rapidly growing mass. In several reports, nearly half the patients had noted the growth for less than a month. More than one third of patients report pain or tenderness associated with the lesion.
The volvar aspect of the forearm is the most common site for nodular fasciitis in adults. After the upper extremity, the next most common sites of involvement are the lower extremity and the trunk.
In infants and children, the head and neck region is commonly involved.
Nodular fasciitis may appear in any superficial soft tissue of the body, including the breast, mucosal surfaces, bladder, and parotid gland.
Diagnosis of nodular fasciitis requires histologic confirmation, and both diagnosis and treatment are accomplished by excisional biopsy. These lesions rarely recur, do not develop metastases, and are readily cured by local excision.
Spontaneous regression of incompletely excised lesions of nodular fasciitis has also been reported. Once the diagnosis is made by excisional biopsy, no further treatment appears necessary.