Infantile Fibromatosis in the Parotid Gland: A Case Report

Abstract

Fibromatosis is a fibroproliferative lesion characterized by aggressive local invasion without regional or distant metastases, the absence of cytologic evidence of malignancy, and a high rate of recurrence. Infantile fibromatosis is a rare disease entity. We report herein on the case of an infant in whom the parotid tumor was growing aggressively, and present some discussion regarding the treatments for infant cases compared with adult cases. A one year and 9 months boy was referred to us for diagnosis and surgical treatments because a right parotid mass had continued to grow for two weeks even though he was taking an antibiotic for what was diagnosed as acute parotitis. The tumor measured 32×30 mm with a smooth surface, was elastic hard and immovable. On the contrary, neither facial palsy, lymph node metastases nor tenderness was found. On imaging examinations, the tumor was identified in the deep lobe of the parotid gland. A surgical resection of the tumor was carried out with preservation of the facial nerve. Histopathological examination showed diffuse proliferation of spindle cells without abnormal mitosis and necroses. Immunohistochemistory of β-catenin revealed the spindle cells were fibroblasts. Finally, taking into account the age and the location of the tumor, the final diagnosis was infantile fibromatosis, destmoid-type. The patient was followed up in our clinic and no recurrence was observed one year after the operation.