Hyalinizing trabecular tumor of the thyroid gland

ABSTRACT

@#A 34-year-old woman with a 4-year history of a slowly enlarging thyroid gland underwent a total thyroidectomy. Histologic sections showed multinodular colloid goiter. In addition, a 1.2 centimeter diameter discrete mass with a solid white cut surface was noted within the left lobe. Sections from the left lobe mass show a well-demarcated tumor whose cells are arranged in trabecular and nested growth patterns. (Figure 1) The cells are polygonal to spindly and have ample eosinophilic, slightly granular cytoplasm and oval to angular nuclei that are often grooved. (Figure 2) Hyaline material and a delicate fibrovascular stroma surround the nests and trabeculae, and occasional psammoma bodies are seen. (Figure 3) These features led us to a diagnosis of hyalinizing trabecular tumor.