A case report on aggressive fibromatosis of the arm and shoulder

Background: Aggressive fibromatosis is a locally aggressive tumor that originates from the deep musculo-aponeurotic structures. In this report, we describe the case of an adolescent male with painless, progressively growing swelling in his right arm necessitated surgical excision and postoperative pathologic examination revealed aggressive fibromatosis. Case presentation: A 15-year-old boy presented with a painless, progressively growing swelling of his right arm. The swelling was firm, non-tender and with restricted mobility. MRI imaging revealed a well-defined, heterogenous, lobulated swelling extending beneath arm and shoulder muscles. Wide local excision of the swelling was done under general anesthesia and pathologic examination revealed aggressive fibromatosis of the arm. Adjuvant radiotherapy was provided to the patient to reduce the risk of local recurrence of the tumor. Conclusion: Aggressive fibromatosis of the upper limb presents as a painless, progressively growing swelling. Assessment with MRI is imperative for making a preliminary diagnosis. Wide local excision with safety margin with adjuvant radiotherapy is the main line of treatment to minimize the incidence of recurrence and preserve the limb.