Background: Ancient schwannoma is an unusual histological variant of schwannoma, which usually arises in the head and neck, thorax, retroperitoneum, pelvis, and extremities. Although 15 cases of primary thyroid schwannomas have been reported in the literature so far, no case of ancient schwannoma has been described in this gland.
Case Report: A 52-year-old woman presented with an asymptomatic right lower neck swelling, which ultrasound scan revealed to be a 3-cm solid nodule in the right thyroid lobe. Preoperative FNAB, revealing only infl ammatory cells, was not conclusive for diagnosis. The patient underwent surgery. The nodule corresponded to a spindle cell tumour with morphological and immunohostochemical features consistent with the diagnosis of “ancient schwannoma”. A review of the literature revealed only 15 cases of intrathyroidal typical schwannomas reported so far. We herein report the first case of a primary thyroid ancient schwannoma, emphasizing its clinico-pathologic features and the differential diagnosis with other primary spindle cell tumour-like and tumour lesions.
Conclusions: We herein report the clinical, radiological, morphological and immunohistochemical features of the fi rst case of an ancient schwannoma occurring within the thyroid gland. As this tumour shows some worrisome morphological features, i.e. atypical cells, awareness and recognition of this rare variant of schwannoma in the thyroid gland is important to avoid a misdiagnosis of malignancy.

Keywords: differential diagnosis, ancient schwannoma, thyroid, review