Incidence of differentiated cancer in nodular goiter

The study aims to determine the incidence of differentiated thyroid cancer in surgically treated thyroid nodules and to study its clinical and pathological aspect. The objective was to formulate a uniform departmental policy for the most appropriate surgical management of this potentially curable disease.

This is a prospective clinicopathological study carried out at the Department of General Surgery, Riyadh Medical Complex, Riyadh, Kingdom of Saudi Arabia, from January 1996 through to December 2000. A total of 483 thyroidectomies were performed. Preoperative diagnosis of thyroid cancer was based on clinical and fine needle aspiration cytology (FNAC). The patients were identified as low risk and high risk groups for surgical treatment. The histopathological diagnosis of differentiated thyroid cancer was confirmed in 103 patients (21.3%). The medical records of all these patients were reviewed for age, sex, clinical presentation, investigations and outcome of surgery.

A total of 103 patients (21.3%) with histopathologically confirmed differentiated thyroid cancer were studied. The female to male ratio was 4:1. The mean age was 36.7 years. Sixty-five percent of patients were between 21-40 years. Nodular goiter was the most frequent presentation observed in 78.6% cases. Fine needle aspiration cytology was suggestive of malignancy in 86.4% cases. Most of the patients (84.5%) were identified as low-risk. Papillary carcinoma was the most common tumor (89%) followed by follicular cancer (8.7%). Eight percent of patients had cervical lymph node involvement at presentation. Total lobectomy was performed in 50.5% and total thyroidectomy in an additional 29% of patients. Overall operative morbidity was 6.8% with zero mortality. Two (1.9%) patients presented with ipsilateral lymph node recurrence with mean follow up of 26.5 months and underwent limited neck dissection.

The relatively high incidence of differentiated thyroid cancer in surgically treated nodular is attributed to increased confidence in FNAC and careful patient selection. Total lobectomy with isthmusectomy for low risk and total thyroidectomy for high risk patients may be recommended as the preferred treatment modalities.