Dermal nodular fasciitis: three case reports of the head and neck and literature review.

Nodular fasciitis is a benign reactive myofibroblastic proliferative process of unknown etiology. It presents as a solitary painless, rapidly growing nodule over several weeks' duration. The condition is self-limited, and proper diagnosis is essential to avoid unnecessary aggressive treatment. Diagnosis is often a challenge because it may be confused with a malignant tumor due to its aggressive clinical behavior and histological features. Immunohistochemical staining can be a useful tool to aid in the diagnosis. Although most commonly located on the extremities and then the trunk, it is estimated that the head and neck region represents only 10 to 20%. The majority of cases arise in the soft tissue, i.e. fascia, muscle, or subcutaneous tissue. Interestingly, cases in the head and neck region often involve dermal tissue. There have been five separate reports documenting rare cases of dermal nodular fasciitis in the dermatopathology literature and one case series involving 28 of 50 dermal variants from the external ear region. We report three additional cases of dermal nodular fasciitis occurring on the left cheek, base of the scalp, and right medial canthus.