Clinical Pathologic Conference Case 3: Nodular Fasciitis

Abstract

Intraoral nodular nodular fasciitis is a rare entity that is important to recognize because it may simulate a malignancy clinically and histologically. The rapid growth and high mitotic index seen in nodular fasciitis may suggest a malignant neoplastic process, but it is generally considered to be a benign reactive proliferation. Recognizing the unique histologic features of nodular fasciitis is important to avoid a possible misdiagnosis as a malignancy, leading to unnecessary further treatment.

A Rare Case of Intraoral Nodular Fasciitis: Diagnosis And Immunohistochemical Profile

“…[2][3][4][5][6][8][9][10] The clinical presentation of NF may mimic other lesions, such as benign proliferative or reaction alterations (ie, fibroma and pyogenic granuloma) or even salivary gland tumors. This clinical differential diagnosis is defined by the association of the history, clinical aspect, and location of the lesion.…”

“…The pathogenesis of NF remains unknown. [2][3][4][5][6]10 However, it seems to be reactive or inflammatory, involving fibroblastic or myofibroblastic proliferation, rather than a true neoplasm.…”

“…1,6 Most NF cases, including the present case, display a cellular morphology and organization similar to those of other neoplasms and require a more thorough investigation with immunohistochemical analysis to elucidate the nature of the lesional spindle cells. 1,3,6,7,10 The immunohistochemical profile of NF includes positive expression for vimentin, a-smooth muscle actin, and muscle-specific actin, indicating myofibroblastic differentiation of spindle cells. 6,7,9 A complementary differential expression is exhibited by the negative reaction of antibodies directed against muscle-specific actin, cytokeratins, desmin, and S-100 protein.…”

“…The treatment for NF consists of conservative surgical excision, 10 although Carli et al 2 reported a case of spontaneous regression of NF with a considerable decrease in size after the completion of an incisional biopsy, which allowed a new but less aggressive surgical intervention. Regression or shrinking of NF can occur from a gradual transition from a loose myxoid component to a more fibrous and compact component.…”

An atypical large ulcero-budding type nodular fasciitis of the hand: a case report

“…It is composed of numerous randomised spindle cells in a fibrous or a myxoid stroma with high mitotic index. 2,6 The three major types of NF are myxoid, fibrous and cellular NF. 5 Many benign and malignant lesions might mimic NF.…”