Histopathologic study of the so called 'palpation thyroiditis'

Transient Hyperthyroidism Induced by Thyroid Ultrasound

OBJECTIVES

Transient hyperthyroidism has been documented following surgical manipulation or direct trauma to the normal thyroid gland. This has best been studied in patients following parathyroidectomy and also reported following trauma to the neck, strangulation, and vigorous palpation of the thyroid gland. It has not previously been reported following a thyroid ultrasound.

METHODS

We report the case of a 58-year-old euthyroid woman with a large nontoxic multinodular goiter who developed transient hyperthyroidism following an ultrasound of the thyroid gland. She was not treated with anti-thyroid medications.

RESULTS

Two weeks later, her free T3 and free T4 were normal, and 11 weeks after the ultrasound, all thyroid tests, including her TSH, were within the reference range.

CONCLUSIONS

We believe this is the first report of a euthyroid individual who developed hyperthyroidism caused by thyroid ultrasonography. We hypothesize that pressure from the ultrasound probe during the examination compressed her large nodules, releasing stored hormone.

Palpation thyroiditis following subtotal parathyroidectomy for hyperparathyroidism

Thyrotoxicosis is an under-recognised but clinically important complication of parathyroidectomy. We report a case of a 37-year-old man with tertiary hyperparathyroidism who initially developed unexplained anxiety, diaphoresis, tachycardia, tremor and hyperreflexia one day after subtotal parathyroidectomy. Thyroid biochemistry revealed suppressed thyroid stimulating hormone and elevated serum free T₄ and free T₃ levels. Technetium-99m scintigraphy scan confirmed diffusely decreased radiotracer uptake consistent with thyroiditis. The patient was diagnosed with thyrotoxicosis resulting from palpation thyroiditis. Administration of oral beta-adrenergic antagonists alleviated his symptoms and there was biochemical evidence of resolution fourteen days later. This case illustrates the need to counsel patients about thyroiditis as one of the potential risks of parathyroid surgery. It also emphasises the need for biochemical surveillance in patients with unexplained symptoms in the post-operative period and may help to minimise further invasive investigations for diagnostic clarification.

Transient hyperthyroidism after surgery for secondary hyperparathyroidism: a common problem

Background

Postoperative hyperthyroidism occurs in approximately one third of patients following parathyroidectomy due to primary hyperparathyroidism (PHP), but has only rarely been described in secondary hyperparathyroidism (SHP). The frequency, course, and laboratory markers of postoperative hyperthyroidism in SHP remain unknown. Our purpose was to evaluate the frequency and the clinical course of postoperative hypcrthyroidism following surgery of SHP and to determine the diagnostic value of thyroglobulin in this setting.

Material and Methods

A total of 40 patients undergoing parathyroidectomy because of SHP were included in this study. Thyroid stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fl4), and thyroglobulin (Tg) were determined one day before and on day 1, 3, 5, 10, and 40 after surgery. At each of these visits patients were clinically evaluated for signs or symptoms of hyperthyroidism.

Results

Biochemical evidence of hyperthyroidism was evident in 77% of patients postoperatively despite of preoperatively normal serum levels. TSH dropped from 1.18 ± 0.06mU/L to 0.15 ± 0.07mU/L (p = 0.0015). Free triiodothyronine (fT3) and fT4 levels increased from 2.86 ± 0.02ng/L and 10.32 ± 0.13ng/L, respectively, to their maximum of 4.83 ± 0.17ng/L and 19.35 ± 0.58ng/L, respectively. Thyroglobulin levels rose from 3.8 ± 0.8ng/mL to 111.8 ± 45.3ng/mL (p < 0.001). At day 40 all thyroid related laboratory values were within normal range. Correlation analysis of postoperative values revealed significant correlations for lowest TSH (r = -0.32; p = 0.038), and highest fT3 (r = 0.55; p < 0.001) and fT4 levels (r = 0.67; p < 0.001) with Tg.

Conclusion

Transient hyperthyroidism is frequent after parathyroidectomy for SHP with Tg being a suitable marker. Awareness of this self-limiting disorder is important to avoid inappropriate and potentially harmful treatment.

Palpation thyroiditis causing new-onset atrial fibrillation

OBJECTIVE

Surgery-induced thyroiditis can pose a significant clinical problem that is underappreciated. We present a case of new-onset atrial fibrillation as a consequence of palpation thyroiditis in a 70-year-old man who underwent radical right neck dissection for malignant melanoma and review the limited literature on this topic.

DESIGN

Biochemical parameters including thyrotropin, free thyroxine, triiodothyronine, erythrocyte sedimentation rate, C-reactive protein, thyroglobulin, thyroid stimulating immunoglobulins, thyroid binding inhibitory immunoglobulins, thyroid peroxidase, thyroglobulin antibodies, and 24-hour urine iodine were measured. Thyroid ultrasound and technetium-99m pertechnetate scintigraphy with radioactive iodine 131 uptake were employed for diagnostic purposes.

MAIN OUTCOME

Following right neck exploratory dissection, the patient developed hyperthyroidism and atrial fibrillation. Imaging studies were compatible with right lobar thyroiditis. Other etiologies of thyroiditis were excluded. Despite normalization of thyroid function after 2 weeks, atrial fibrillation persisted and required cardioversion.

CONCLUSIONS

Manipulation of the thyroid gland during neck exploratory surgery can result in hyperthyroidism with atrial fibrillation as a consequence. To avoid this complication, careful attention should be paid during surgical procedures or other clinical situations in which the thyroid gland is manipulated.

Hyperthyroidism after parathyroid exploration

BACKGROUND

We hypothesized that hyperthyroidism after parathyroid exploration may be an underreported phenomenon with a course more severe than recognized previously.

METHODS

We examined pre- and postoperative thyroid function and outcomes in 199 consecutive patients who, since March 2000, had parathyroid exploration for primary sporadic hyperparathyroidism (HPTH). We excluded patients with prior thyroid or parathyroid surgery, preoperative thyroid medication, concurrent total thyroidectomy, or follow-up <5 months.

RESULTS

Of 125 patients with normal preoperative serum thyroid-stimulating hormone levels, 39 (31.2%) were hyperthyroid postoperatively. Mean thyroid-stimulating hormone levels (mean +/- SD) dropped with operation from 2.0 +/- 1.1 microIU/mL to 1.2 +/- 1.4 microIU/mL (P < .0001). Nineteen patients (15%) reported symptoms 1 to 2 weeks after operation. The clinical course of hyperthyroidism typically was short, but 5 patients (4%) had symptomatic hyperthyroxinemia requiring medical therapy. Hyperthyroidism was independent of age, severity of HPTH, anatomic/pathologic features, operative time, and other measures of operative difficulty, but was associated with lithium therapy, bilateral exploration, and absence of concurrent thyroid lobectomy.

CONCLUSIONS

Risk of hyperthyroidism may be underappreciated after routine parathyroid surgery for HPTH. Use of lithium and degree of dissection appear contributory. Patients undergoing parathyroid exploration need counseling and surveillance for hyperthyroidism, which may be reduced by minimizing the extent of parathyroid surgery.