Diffuse sclerosing variant of thyroid papillary carcinoma: Diagnostic challenges occur with Hashimoto's thyroiditis

Abstract

Diffuse sclerosing papillary thyroid carcinoma (DSPTC) is a relatively rare variant of papillary thyroid carcinoma with distinct histological features, radiological characteristics, and biological aggressiveness. Compared with conventional papillary thyroid carcinoma, DSPTC is characterized by scattered microscopic tumor islands, diffuse fibrosis, calcification, and abundant lymphocytic aggregation. A preoperative diagnosis is challenging in the absence of nodules and scanty fine needle aspiration cytology samples. We describe a unique DSPTC patient, an 18-year-old woman who presented with a neck mass that grew slowly for 2 years. The palpable neck mass was nontender, well defined, firm, and unmovable. Laboratory studies showed normal thyroid function and positive autoimmune markers: antithyroglobulin antibody = 1:1600 and antimicrosomal antibody = 1:1600. A neck ultrasound showed diffusely prominent microcalcifications with one small vague nodule. Hashimoto's thyroiditis with an accompanying malignancy was suspected. Based on the result of intraoperative pathology reports, the patient was given a total thyroidectomy. Lymph node dissection and histological analysis revealed bilateral DSPTC in addition to lymphocytic thyroiditis in nonmalignant areas of the thyroid. Clinical and histological diagnostic challenges usually occur when DSPTC presents with a diffuse thyroid enlargement, dispersed microscopic tumor islands (frequently without mass formation), extensive fibrosis, and abundant lymphocytic infiltration mimicking thyroiditis.

Shear wave elastography diagnosis of the diffuse sclerosing variant of papillary thyroid carcinoma: A case report

“…This is characterized by high aggressiveness, a larger tumor size, a high incidence of cervical lymph node metastasis and distant metastasis (3,(5)(6)(7)(8)(9). DSVPTC is also associated with frequent local recurrence and poor prognosis (8)(9)(10)(11).…”

“…This is characterized by high aggressiveness, a larger tumor size, a high incidence of cervical lymph node metastasis and distant metastasis (3,(5)(6)(7)(8)(9). DSVPTC is also associated with frequent local recurrence and poor prognosis (8)(9)(10)(11). Therefore, patients with DSVPTC must be treated by aggressive surgical intervention, including total thyroidectomy, central neck dissection, bilateral neck dissections and postoperative radioiodine treatment (3,9,10,12).…”

“…Therefore, patients with DSVPTC must be treated by aggressive surgical intervention, including total thyroidectomy, central neck dissection, bilateral neck dissections and postoperative radioiodine treatment (3,9,10,12). Patients with DSVPTC must be monitored closely during follow-up for any disease recurrence or metastasis (3,7,9,12).…”

“…Clinically, the diagnosis of DSVPTC is often delayed by months or years as a result of the clinical similarities that it shares with autoimmune lymphocytic thyroiditis (also termed Hashimoto's thyroiditis) (3,7,9,12). Due to the early spread of DSVPTC, early correct diagnosis and surgical treatment is crucially important (9).…”

“…Due to the early spread of DSVPTC, early correct diagnosis and surgical treatment is crucially important (9). Currently, ultrasound (US) is generally considered to be the most accurate imaging modality for the evaluation and characterization of thyroid nodules (13).…”