Spindle Epithelial Tumor with Thymus-Like Differentiation (SETTLE): A Case Report.

Background: Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a tumor with an indolent disease course and late metastatic potential. It occurs primarily in children and adolescents, although it can present later in life. It was first described by Chan and Rosai [Tumors of the neck showing thymic or related branchial pouch differentiation: a unifying concept. Hum Pathol. 1991;22(4):349-67. doi:10.1016/0046-8177(91)90083-2], and there have been approximately 46 cases published in the English literature. Case report: We present an 8-year-old female with a SETTLE, undergoing an initial fine-needle aspiration and later a diagnostic biopsy. There is no evidence of disease recurrence at 3.5 years of follow-up. Conclusion: Though fine-needle aspirate biopsy is useful in directing the diagnostic workup of SETTLE by indicating concerning pathology, the broad differential diagnosis associated with it requires histology in conjunction with a limited immunohistochemical panel and unremarkable cytogenetics workup. Surgical resection is the main stay of treatment, and long-term follow-up is important in these patients.

The thyroid nodules in kids study (ThyNK study): An evaluation of clinical practice variation.

PURPOSE: The purpose of this study was to evaluate the management of thyroid nodules in children and assess clinical practice variation (CPV) using the 2015 American Thyroid Association (ATA) guidelines as a standard. METHODS: Pediatric patients presenting to a tertiary care pediatric centre with a thyroid nodule from 2007 to 2017 were retrospectively analyzed. Demographic and disease specific information were collected. CPV and adherence to ATA guidelines were explored. RESULTS: Of 86 patient records reviewed, 47 (55%) were managed operatively (mean age 14.4, 59F:27M). Fifteen patients (17%) had malignant pathology, and 11/15 (73%) were papillary carcinoma. Of the 47 operative patients, 7 (15%) had no preoperative ultrasound, and 12 patients (26%) did not have preoperative cytology. All patients with low TSH had scintigraphy appropriately performed, and 1 patient with high/normal TSH did not have a preoperative FNA obtained. All differentiated thyroid cancers were appropriately managed with hemithyroidectomy or total thyroidectomy based on pathology. Where CPV from the guidelines was noted, it was associated with complex presentation, the surgeon's decision to proceed to surgery directly, and/or rare pathologies. CONCLUSION: The ATA guidelines provide a valuable framework for the management of pediatric thyroid nodules, but CPV persists given patient/disease complexity and heterogeneity. TYPE OF STUDY: Case Series with No Comparison Groups. LEVEL OF EVIDENCE: Level VI: Case series with no comparison groups.