Renal metastasis is relatively unusual in patients with differentiated thyroid carcinoma.

The clinicoradiological parameters of a series of patients with differentiated thyroid carcinoma and renal metastasis were assessed, together with follow-up data.

The series comprised 4 male patients over the age of 45 years with extensive disease at the primary site. Retro-sternal extension of a large goitre was observed in three patients. The primary tumour was 4 cm or larger in all patients (range, 4–14 cm), and three patients had associated lymph node metastasis. None had any genito-urinary symptoms at presentation. Two patients had isolated renal metastases with no other distant metastases, while the others had extensive multi-organ involvement. The bilateral occurrence of lesions was a hallmark, being observed in all cases. Ultrasound-guided fine needle aspiration cytology and 131I scintigraphy were pivotal in confirming the diagnosis. Evidence of ‘flip-flop’ between 131I study and fluoro-deoxyglucose positron emission tomography was noted in one patient, while the other three demonstrated concordant lesions in both modalities. At a minimum follow-up period of four years after diagnosis, three patients demonstrated stable disease with radioiodine therapy, and one had expired due to a poorly differentiated lung carcinoma which developed subsequently.

Central compartment neck dissection is increasingly performed as part of surgical management of differentiated thyroid carcinoma. However, elective central neck dissection remains controversial due to complications and lack of evidence of survival benefit.

To investigate and compare rates of transient and permanent hypocalcaemia following total thyroidectomy alone, compared with total thyroidectomy with central neck dissection, for differentiated thyroid carcinoma.

Retrospective study of 127 consecutive patients referred with differentiated thyroid carcinoma, 2004–2006; 78 patients had undergone total thyroidectomy (group one) and 49 total thyroidectomy with central compartment node dissection (group two). Surgery was performed in various hospitals by both otolaryngologists and endocrine surgeons.

In groups one and two, the incidence of transient hypocalcaemia was 18 per cent (14/78) and 51 per cent (25/49) (p < 0.001), and the incidence of permanent hypocalcaemia 1 per cent (one of 77) and 12 per cent (six of 49) (p < 0.01), respectively. Most patients undergoing central neck dissection had evidence of pathological level six lymphadenopathy (29/49).

Total thyroidectomy combined with central neck dissection for the treatment of differentiated thyroid carcinoma is more likely to result in transient (51 per cent) and permanent (12 per cent) hypocalcaemia. Elective neck dissection should be performed selectively, with a high expectation of post-operative hypocalcaemia.