THYROID-TUMORS IN A GOITER-ENDEMIC REGION OF NIGERIA - PATHOLOGICAL-STUDY OF 48 CASES

Background - Plateau State is one of the documented goitre-endemic zones in Nigeria prompting the need to determine the incidence and pattern of thyroid tumours in Jos. Method - Forty-eight thyroid tumours received from the Jos area over a 5-year period (1985-89) were reviewed noting the age, sex, tumour weight, widest diameter and the histological diagnosis of paraffin wax embedded surgical specimens. Routine and special stains were employed. Careful search for vessel/capsule invasion was made and excised lymph nodes when available were screened for secondaries. The estimated population of Jos was noted. Results - The incidence is 10.1 per 100,000 with a female:male ratio of 3.4:1 and a peak in the 4th decade. Follicular adenomas (45.8%) have an incidence of 4.6 per 100,000 (F:M = 6.3:1, median age = 34 years) and thyroid malignancies (54.2%), 5.5 per 100,000 (F:M = 2.3:1, median age = 40 years). Of the malignant cases, follicular, medullary and papillary account for 53.8%, 23.1% and 19.2% respectively. Clinical presentation is preceeded on average by 8 years of neck swelling. Venous invasion was observed in 87.5% of cases of thyroid malignancy and cervical lymph node metastasis was histologically confirmed in some cases. Conclusions - Jos has a high incidence of thyroid tumours compared with reports from other regions. Thyroid carcinoma can be found in the 2nd and 3rd decades in this environment and the follicular type is the most common.