Background: Aggressive fibromatosis is rare in the neck and superior mediastinal area

Case Report: A 76-year-old woman initially presented with a large anterior neck mass with upper airway obstruction due to tracheal compression. Initial biopsy report suggested follicular carcinoma, but final diagnosis was aggressive fibromatosis. Surgical excision was performed 3 years after the initial presentation, followed by post-operative radiation due to positive margin. No evidence of disease recurrence was observed during the 3-year follow up.

Conclusion: Aggressive fibromatosis of head and neck is a challenging lesion due to its infiltrative nature, high propencity to recur and proximity to vital structures. Surgery should be well-planned using imaging and multidisciplinary approaches.

Keywords: Thailand, aggressive fibromatosis, desmoid, tracheal compression, mediastinum