Detection of <scp>STRN‐ALK</scp> fusion in thyroid nodules with indeterminate cytopathology facilitates papillary thyroid cancer diagnosis

Thyroid cancer is the most common endocrine malignancy. Approximately 70% of cases of papillary thyroid carcinoma and 50% of poorly differentiated and anaplastic thyroid carcinoma harbor well-characterized driver mutations and chromosomal rearrangements that drive tumorigenesis. Molecular profiling has been helpful in identifying and informing follow-up strategies in tumors with more aggressive trajectories. Here, we report a case of papillary thyroid cancer (PTC) discovered in a patient with thyroid nodules with relatively benign ultrasound and fine needle aspiration (FNA) findings. Molecular testing in this patient identified a rare STRN-ALK fusion in two thyroid nodules with indeterminate and/or benign cytology. This led to the patient undergoing a thyroid lobectomy and a subsequent confirmation of papillary thyroid carcinoma upon resection. The report highlights the role of comprehensive molecular testing in thyroid lesions of indeterminate cytology.