| Brix et al., Odense, Denmark, investigated the genetic contribution to the etiology of non-autoimmune non-toxic goiter in a well-defined population of Danish female twins. In total 2945 female/female twin pairs born between 1953–1972 were studied and information on thyroid disease was obtained from this cohort. A total of 69 subjects (1.2%) representing 59 twin pairs could be classified as having or having had, non-toxic goiter. The probandwise concordance rate was 0.52 for monozygotic twins and 0.13 for dizygotic pairs. When adjusted for age at onset of goiter, and age at last observation of unaffected cotwins, the cumulative probandwise risk of developing non-toxic goiter from birth to age 42 was 0.76 for monozygotic twins and 0.19 for dizygotic twins (p <0,05). The tetrachoric correlations were 0.91 and 0.55 respectively. Model-fitting analysis suggested that the heritability of the liability to the development of non-toxic goiter in women is 91%, while individual-specific environmental factors not shared by cotwins seem to explain the remaining 9%. The authors conclude that genetic factors play a major role in the etiology of non-toxic non-autoimmune goiter in women. This study was done in an area of borderline iodine deficiency without endemic goiter. (Comment: This study shows that in this type of goiter, genetic factors are very important and maybe even more so than in autoimmune type of goiter.) Förster et al., Mainz, Germany, studied the effect of weight adjusted T4 (1.4 µg/kg body weight + 150 µg iodide daily treatment versus a fixed combination of 100µg T4 + 100 µg iodide daily) on TSH suppression and decrease of thyroid volume in an area with endemic goiter. During treatment, 40% of the T4 titrated group had a TSH level of <0.1 mU/l, while this was only the case in 12.5% in the fixed combination group. Despite these differences thyroid volume decreased in the two groups to the same extent i.e. 37.6% and 30.9% respectively. No side effects in either group were noted. The authors conclude from this randomized study that both treatment regimens have similar efficacy and tolerance. Wesche et al., Amsterdam, The Netherlands, performed a randomized clinical trial in consecutive patients on the efficacy and side effects of I–131(median dose 888 Mbq) treatment in patients with sporadic non-toxic goiter. Results were compared to TSH suppressing L-T4 treatment (group A and B respectively). Group A consisted of 25 patients and B of 22, with stratification for sex and menopausal age. Bone parameters: serum alkaline phosphatase and osteocalcin, and urinary hydroxyprolin/creatinine ratio, bone mineral density at the lumbar spine, trochanter, and collum femoris. Efficacy: group A: 24/25 patients responded with a median decrease in thyroid volume (ultra sound) of 46% after 1 year and 52% after 2 years. These figures were for group B 11/22, 25% and 22% respectively. Side effects: group A mild radiation thyroiditis and after 2 years 13/25 euthyroid, 9/25 hypothyroid, and 3/25 subclinically hypothyroid. Group B: 5/22 developed thyrotoxic symptoms and 1/22 atrial fibrillation. All markers of bone formation and resorption increased significantly in group B but not in group A. No changes in bone mineral density were observed in group A, but subjects in group B showed a significant reduction, in the lumbar spine and in the collum femoris both in pre- and in postmenopausal women. (Comment: This is an informative study and shows us that TSH-suppressive T4 therapy for sporadic non-toxic goiter is not a first-choice, if any, for therapy. It is less efficacious than treatment with radioactive iodine and has serious side effects.) Benvenga et al., Messina, Italy, compared efficacy of TSH suppressive T4 therapy in patients with the nodular variant of Hashimoto’s thyroiditis (HT) (n = 40, female 39) and in patients with non-toxic goiter (NTG) (n = 50, female 46). Each group was subdivided in having a single nodule (SN) or multiple nodules (MN). In the SN subgroup, the size of the nodule decreased in 6/11 HT and 6/19 NTG. The percentage increase in nodule size was 9% and 5% respectively. New nodule formation was 27 and 53% respectively. In the MN subgroup the size of the nodules decreased in 4/29 HT and 6/31 NTG. Percentages of increase during T4 therapy were 10% and 0% respectively. (Comment: No information is available on parameters as reported in the previous study i.e. general symptoms, heart and bone effects.) Kim et al., Seoul, Korea, performed percutaneous ethanol injection (PEI) in guided ultrasonography in 90 patients with hot and cold nodules. In all cases fine needle aspiration biopsy was performed. Response rate (i.e. disappearance) for solid nodules were complete in 93/117, partial in 22/117, and absent in 2/117. In a small group of 11 patients with pure cysts the results were 7/11, 3/11, and 1/11 respectively. (Comment: PEI in this study seems to be a very good choice for initial therapy when the presence of malignancy is improbable. The side effects that were reported in this study included transient neck pain 10/117, transient unilateral focal cord palsy 1/117, and miscellaneous 3/117.) Doran et al., Rochester, MI, USA, retrospectively studied 100 consecutive patients with either a solitary or a dominant nodule in a multinodular goiter evaluated by palpation and/or ultrasound between 1983 and 1997. Seventy-five were women, mean age 51 yr., 40 patients with a solitary nodule and 60 with a dominant nodule in a multinodular goiter. Of these nodules 8% were pure cysts, others were solid or semi-solid. During the entire follow-up period 26% of solitary/dominant nodules increased, 54% remained unchanged, 14% decreased in size, and 6% disappeared. The mean interval by which ultrasound detected an increase in size was 4.66 years. Only 2 nodules ultimately appeared to be malignant, both of the papillary type. Monteiro et al., Săo Paulo, Brazil, submitted 32 patients with thyroid nodules (single 28 and multiple 4) to color Doppler flow mapping (CDFM) in order to analyze whether this technique allows differentiation between benign and malignant nodules. All patients underwent fine needle aspiration biopsy and subsequent surgery. CFDM patterns were classified as follows: presence of perinodular vascularisation and presence and grading of intranodular vascularisation. Abundant intranodular vascularisation would indicate malignancy. Sensitivity, specificity, positive predictive value, and accuracy to identify malignancy of CFDM were 36.8%, 64.7%, 53.8%, and 50% respectively. The authors conclude that CDFM has limited diagnostic value with regard to possible presence of malignancy. Niepomniszcze et al., Buenos Aires, Argentina, followed two groups of patients with regard to the evolution of single benign thyroid nodules. Group I (n = 78) was treated with thyroid hormone: either 100µg T4, 40 µg T3, or 50 µg T4 + 20 µg T3. Group II (n = 25) served as a control group. Palpation and ultrasound were used to evaluate the evolution of thyroid nodules in a period of 4–6 months. The results were that there was no difference in percentage of patients showing a decrease in nodule size; group I versus group II 43.6% vs. 36%. (Comment: Although I am personally generally not in favor of treatment of solitary nodules with TSH suppressive therapy, which standpoint seems to be supported by the present findings, we should realize that the treatment period in this study is in fact too short for final evaluation of the results.) |
