Endocrine Abstracts

Introduction: Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) represents a rare but rather more aggressive subtype of PTC.

Purpose: Description of a patient with DSPC and background autoimmune thyroiditis.

Case description: A 33-year-old female patient reported extensive neck swelling that had progressed over several months. The patient had been diagnosed with hypothyroidism attributed to autoimmune thyroiditis, 3 years before. At that time, goiter was also found with a reported predominant nodule in the right lobe. On examination, the patient was euthyroid, with a palpable enlargement of the right lobe and isthmus, with particularly hard texture. Ultrasound imaging revealed diffuse enlargement of the thyroid gland particularly of the right lobe, where a formation of a suspicious mass was noted. Linear hyperechogenic foci were dispersed throughout the entire thyroid surface. Hypoechogenic areas with ill-defined borders were noted centrally, possibly representing lymph nodes. A fine-needle aspiration biopsy of the right lobe was positive for papillary thyroid cancer and the patient underwent total thyroidectomy. Histopathology showed a 2.4 cm papillary carcinoma of the right lobe, with psammomatus bodies, squamous metaplasia, and background sclerosis. Vascular infiltration by the tumor cells was present. The remaining thyroid parenchyma exhibited extensive lymphocytic and plasmatocytic infiltrates with abundant lymphoblastic centers. Dispersed foci of the neoplasm were observed in all sections of the entire gland. Metastases were recognized in 3 excised central lymph nodes. A few weeks later the patient underwent a completion surgery with central and right lateral compartment exploration, with metastases found in 13/24 and 4/30 lymph nodes, respectively.

Conclusions: The imaging characteristics and the overlapping presence of Hashimoto’s thyroiditis can lead to a delayed diagnosis of DSPC. Considering the more aggressive nature of this variant, raising awareness for early recognition of its particular ultrasonographic characteristics is of paramount importance for effective treatment and improved prognosis.