We report a desmoid tumor in a 75-year-old man, who presented with a tumor in the posterior neck in July 2003. The patient had a history of left lobectomy and neck dissection for thyroid carcinoma in September 2000.
CT findings indicated a large strongly enhanced tumor located in the posterior neck.
On T1-weighted MRI, the tumor was isointense to muscle and heterogeneously enhanced with gadolinium. The lesion also exhibited a high intensity on T2-weighted MRI.
PET showed FDG accumulation in the tumor, while 201mT1 scintigraphy showed T1 uptake in the tumor, suspected the recurrence of thyroid carcinoma. The tumor was excised under general anesthesia in November 2003. At surgery, the lesion was adherent to the surrounding tissue, but there were no post-operative neurological problems.
Pathological examination demonstrated multiplication of fibroblasts and abundant collagen but there were no remarkable features for example fission and necrosis, suggesting malignancy. However, the tumor showed a tendency to infiltrate by extension between individual muscle fibers.
From available information, desmoid tumors of the head and neck are rare, especially in the posterior neck lesions. These lesions are fibrous neoplasms with a good prognosis but significant morbidity with the potential for locally aggressive growth invading surrounding structures. The complicated anatomy of the head and neck seems to generate a tendency toward such lesions, but they do not display any metastatic potential clinically.
We have not detected any postoparative recurrence of the tumor for seven months to date.