Endocrine Abstracts

Case history

A 27 year-old woman presents with a right 3 cm. papillary thyroid cancer (PTC) with lateral cervical lymph node metastasis. Her past history is irrelevant. Treatment consists of total thyroidectomy plus lymphadenectomy of compartments II-III-IV-VI. iPTH and s-Ca concentrations at 24 h were 6 pg/ml and 7 mg/dl respectively. Replacement therapy (calcium + calcitriol) was required for three months (protracted hypoparathyroidism). Pathology reveals a 27 mm. non-encapsulated PTC of follicular variant, with 0N+/6N in the central neck and 6N+/24N in the lateral neck (T2N1bM0, skip metastasis). One ipsilateral parathyroid gland was found in the specimen (PGRIS 3). At three months postop her stimulated Tg was undetectable and iPTH 39 pg/ml. Suppressive T4 was administered for three years. No radioidine ablation was performed. The patient has been followed wit basal Tg determinations and neck ultrasound once a year for ten years and then every two years up to 20 years. She is currently disease-free.

Comment

There is no such thing as “differentiated thyroid cancer”. PTC and follicular thyroid cancer have different clinical presentation, biological behaviour and require different therapeutic approaches and risk assessment. RAI ablation is losing momentum in the treatment of PTC because specialized surgical treatment can render patients biochemically cured. Survival and recurrence rates of classical PTC completely resected and with no distant metastasis, are not influenced by RAI ablation. Thorough surgery including total thyroidectomy, routine central neck dissection plus elective lateral dissection based on preoperative ultrasound, and a bland follow-up is all that is needed for most patients with PTC. Permanent hypoparathyroidism remains the main postoperative complication, but it can be minimized (< 5%) by avoiding accidental parathyroidectomy and autotransplantation, and referring patients to high-volume centres. Routine postoperative scans, repeated thyroglobulin stimulations and aggressive imaging techniques to investigate minimally elevated thyroglobulin concentrations are obsolete.