Objective: To study clinical features and pathological results of patients with solitary thyroid nodules that underwent surgery in Trang Hospital and develop a management guideline for setting of Trang Hospital.

Materials and methods: A retrospective descriptive study. Medical records of patient with solitary thyroid nodule that underwent surgery in Trang Hospital during January 2002 to September 2010 were reviewed. Demographic data, clinical, laboratory and pathological findings were collected and data were analyzed.

Results: Total of 620 patients were included in the study with male to female ratio of 1:11.5. The average age was 40.5 years. Most patients were in age group of 31-40 years. The average duration of disease was 28.3 months. The average size of nodules was 2.8 cm. Eighty-nine percent of patients that had a thyroid function test were euthyroid. Most patients had fine needle aspiration cytology (FNAC) before surgery, FNAC results had likelihood ratio of 14.8 for prediction of malignancy. Seventy-eight point one percent of pathological results were benign and 21.9% were malignant. Nodular goiter was the most common in benign lesions, while well-differentiated cancer was the most common in malignant lesions. Risk of malignancy was significantly high in patients with age of 30 years or less, or with hypothyroid than other groups.

Conclusions: Most of solitary thyroid nodules are benign and can be treated conservatively. A thorough clinical assessment along with FNAC can avoid unnecessary operation.

Key words: solitary thyroid nodule