Papillary thyroid carcinoma with desmoid fibromatosis: a case report and review of literature.

Desmoid-type fibromatosis (DF) is a rare monoclonal, fibroblastic proliferation characterized by an unpredictable and variable clinical course. We present the case of a 56-year-old woman who underwent total thyroidectomy for papillary thyroid carcinoma in 2012 and who developed a cervical mass at the left laterocervical level during follow-up, raising the diagnosis of tumor recurrence. Computed tomography of the neck showed solid formations with heterogeneous contrast uptake in the right lateral region of the neck. At the level of the thoracic operculum, a second 26-mm formation was observed that medially contacted the left lateral wall of the trachea. Lateral lymphadenectomy was performed, which was incomplete. Histology showed findings consistent with desmoid-type fibromatosis. DF are slowly proliferating, non-metastatic tumors with a highly invasive capacity that are usually present in familial adenomatous polyposis (FAP)-Gardner syndrome. Our case had a history of massive colonic polyposis and first-degree relatives of colorectal cancer.