Incidental diagnosis of the tall-cell variant of the papillary microcarcinoma of the thyroid gland requires completion lymphadenectomy: case report.

Papillary thyroid carcinoma is the most common neoplasm of the thyroid gland which is usually associated with a very good prognosis. The aim of this case report is to present the disease course of a rare tumor of the thyroid gland, which is worthwhile due to its extraordinary appearance and specific management. A 46-year-old patient presented with a pronounced right-sided, but bilateral, multinodular goiter, with a volume of approximately 80 mL, as assessed on ultrasonography. Surgical removal was indicated as scintigraphy showed a 4-cm cold nodule that almost completely took up the right thyroid lobe. Because of the micronodular texture of the left thyroid lobe, complete thyroidectomy was performed according to well-established guidelines. Histopathological investigation of the specimen revealed a follicular adenoma without any malignancy in the right thyroid lobe and the tall-cell variant of the papillary thyroid microcarcinoma in the left lobe, with a capsular invasion and diameter of 0.6 cm. Because this rare tumor subtype is known for its aggressive behavior, and there was capsular invasion, low-grade differentiation, and an increased risk for lymphatic metastases, completion lymphadenectomy of the central compartments was performed after an interdisciplinary board decision. On histopathology, there were 30 tumor-free lymph nodes; final TNM classification was as follows: pT3 pN0 [0/30] L0 V0 Pn0 R0). The postoperative course was uneventful, and surgery was followed by radioiodine therapy. Six months after the surgery, clinical follow-up did revealed any sign of recurrence. The tall-cell variant is a rare and aggressive subtype of the papillary thyroid carcinoma, and it is characterized by poor 5-year survival and high recurrence rate. According to our understanding and based on current literature, this disease requires an aggressive surgical treatment and a close follow-up, as recommended by the current guidelines.