Desmoid fibromatosis in thyroid bed: a case report

Summary

Desmoid tumors are rare formations of fibroblastic origin thought benign and slow growing, but could be aggressive in behaviour invading the surrounding areas. The aim of this report is to present a case of a patient with desmoid tumor located in anterior cervical region mimicking malignant formation. A 69-year-old female patient with previous history of surgery due to multinodular goiter as well as primary hyperparathyroidism caused by parathyroid adenoma was scheduled to ultrasound of the neck due to hoarseness. Ultrasound revealed extremely hard, isoechoic, poorly defined nodule with calcification in thyroid bed suggestive of malignant tissue. The finding of fine needle aspiration cytology report showed rare spindle cells but was inconclusive. Other imaging techniques like computed tomography and magnetic resonance imaging were suggestive for paraganglioma or parathyroid adenoma, but another etiology could not be ruled out with certainty and complete surgical resection was recommended. Pathology report was consistent with fibromatosis, leading to the final diagnosis of extra-abdominal desmoid tumor. Although desmoid tumor is generally a benign disease, it can sometimes be locally aggressive invading the surrounding tissue and mimicking the picture of a malignant process with difficulties to remove surgically, as in our case. Moreover, even after complete excision, recurrence of the disease often occurs that should be kept in mind and such patients should be monitored periodically.