Endocrine Abstracts

Background: Branchial cleft cysts account for almost 20 percent of pediatric neck masses. They are usually present in late childhood or early adulthood, when a previously unrecognized cyst becomes infected. First branchial cleft cysts typically appear on the face near the auricle. Second branchial cleft cysts are the most common and they are usually located just inferior to the angle of the mandible and anterior to the sternocleidomastoid muscle. Third branchial cleft cysts are typically located lower in the neck than the second one. First step in management is controlling infection, if present. Once the infection has been resolved, the mass is usually excised to prevent future complications.

Case presentation: A 72-year-old man was incidentally found to have a nodule in left thyroid lobule (LTL) during the performance of a carotid doppler ultrasound. The patient had personal history of transient ischemic attack in 2016, type 2 diabetes, dyslipidemia, arterial hypertension, Wolf-Parkinson-White syndrome and prostate carcinoma (in remission). He followed treatment with aspirin, metformin, atorvastatin and ramipril). There was no family history of thyroid carcinoma. Palpation of the neck was normal. He presented normal thyroid hormone levels with positive autoimmunity. Thyroid ultrasound reported a normal size gland with 2 hyperechoic micronodules without suspicions characteristics in right lobule and one solid nodule (13 mm, markedly hypoechoic, heterogeneous with lobulated surroundings) in LTL, suggesting a malignant nodule (TIRADS4c). Ultrasound guided fine-needle aspiration cytology was performed, which revealed four times insufficient specimen (Bethesda I) describing: protein hemorrhagic background with abundant anucleated cytoplasms and mature flat pavement cells, as well as crystalline deposits, without thyroid elements or with 3–4 follicular groups insufficient for diagnosis. With these results, a left hemithyroidectomy was performed.

Examination of the pathology sample reported an intrathyroidal branchial cleft cyst with collapsed light, microscopically, presented occasional anucleated laminates and cellular detritus, which were coated by squamosian epithelium without grain, lacking of atypia. Also, an incidental 1 mm papillary carcinoma was found, with free resection margins.

Conclusion: This report represents a rare case of branchial cleft cyst because of the location and the age of our patient. The literature review reveals the existence of only 6 cases of intrathyroidal branchial cleft cyst. There are not specific ultrasound or cytology characteristics, resulting in the need for surgery to reach a diagnosis.