Distant solitary skeletal muscle metastasis from papillary thyroid carcinoma.

An unusual case of isolated trapezoid muscle metastasis from a papillary carcinoma of the thyroid gland is described. Although extrathyroidal extension to the soft tissues of the neck may occur, distant metastases are rare in papillary thyroid carcinoma. Skeletal muscle metastasis from a differentiated thyroid carcinoma seems to be extremely rare, even for the follicular type of this cancer, well known for its hematogenous spread to various sites.