Cardiac effect of thyrotoxicosis in acromegaly

The outcome of TSHoma from a tertiary care institute in India

Background:

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) is the rarest functioning pituitary adenoma.

Methods:

A retrospective analysis of eight patients of TSHomas to highlight the presentations, diagnostic challenges, and treatment outcomes.

Results:

Median age at diagnosis was 42 years, median latency to diagnosis was 2.5 years, and thyrotoxic and compressive symptoms were the most common presenting symptoms. At presentation, three cases were plurihormonal, six cases were on medical treatment including thyroxine, and two cases were incidentally discovered. Imaging revealed macroadenoma in all cases. Seven cases underwent pituitary surgery, after which three achieved remission. Another case entered remission after adjunctive radiotherapy. Thyrotropin (TSH) immunostaining was demonstrated in six out of seven adenomas.

Conclusion:

TSHoma is a rare functioning pituitary tumor with both silent and symptomatic presentations. Diagnosis can be established with biochemical and imaging features, even without dynamic tests.

Thyroid diseases in patients with acromegaly

Acromegaly often involves the presence of different pathologies of the thyroid gland. Long-lasting stimulation of the follicular epithelium by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) can cause disorders in thyroid function, an increase in its mass and the development of goitre. Acromegalic patients present most frequently with non-toxic multinodular goitre. Nodules are more prevalent in patients with active acromegaly. It has been suggested that then thyroid size increases and it can be reduced through treatment with somatostatin analogues. The relationship between thyroid volume and the level of IGF-1 and the duration of the disease is unclear. Each acromegalic patient requires a hormonal and imaging evaluation of the thyroid when the diagnosis is made, and an accurate evaluation during further observation and treatment. Although the data concerning the co-occurrence of acromegaly and thyroid cancer still remain controversial, it is particularly important to diagnose the patient early and to rule out thyroid cancer.

"Glandular intoxication" following emergent tracheotomy during transsphenoidal surgery for acromegaly: Cushing's 1910 unrecognized case of thyroid storm?

Harvey Cushing's monograph The Pituitary Body and Its Disorders describes Case XXXVIII, H. M. B., a 33 year-old man who presented with acromegaly in 1910. The detailed operative note reports an emergency tracheotomy performed following induction of anesthesia, and immediately prior to a naso-labial approach to a suspected sellar lesion. Cushing's post-operative notes document a significant increase in temperature prior to the patient's death. Cushing offered an explanation for the patient's symptoms immediately pre-mortem, which is largely unsatisfying. Following institutional review board approval, and through the courtesy of the Alan Mason Chesney Archives, the surgical records from the Johns Hopkins Hospital, 1896-1912, were reviewed. A review of the original surgical file revealed a more extensive description of the emergent tracheotomy required following induction of anesthesia, and provided additional information regarding the patient's symptoms in the immediate pre-mortem period. Namely, the urgent tracheotomy transected the thyroid gland, and post-operatively the patient experienced significant tachycardia and hyperthermia, consistent with thyroid storm. The new information regarding the hospital course of H. M. B. offers insight into the previously incompletely described circumstances surrounding his emergent tracheotomy, and subsequent death. Additionally, the case underscores the clinical importance of recognizing and appropriately treating thyroid storm.

Cardiovascular complications in acromegaly: methods of assessment

Cardiac involvement is common in acromegaly. Evidence for cardiac hypertrophy, dilation and diastolic filling abnormalities has been widely reported in literature. Generally, ventricular hypertrophy is revealed by echocardiography but early data referred increased cardiac size by standard X-ray. Besides, echocardiography investigates cardiac function and value disease. There are new technologic advances in ultrasonic imaging. Pulsed Tissue Doppler is a new non-invasive ultrasound tool which extends Doppler applications beyond the analysis of intra-cardiac flow velocities until the quantitative assessment of the regional myocardial left ventricular wall motion, measuring directly velocities and time intervals of myocardium. The radionuclide techniques permit to study better the cardiac performance. In fact, diastolic as well as systolic function can be assessed at rest and at peak exercise by equilibrium radionuclide angiography. This method has a main advantage of providing direct evaluation of ventricular function, being operator independent. Coronary artery disease has been poorly studied mainly because of the necessity to perform invasive procedures. Only a few cases have been reported with heart failure study by coronarography and having alterations of perfusion which ameliorated after somatostatin analog treatment. More recently, a few data have been presented using perfusional scintigraphy in acromegaly, even if coronary artery disease does not seem very frequent in acromegaly. Doppler analysis of carotid arteries can be also performed to investigate atherosclerosis: however, patients with active acromegaly have endothelial dysfunction more than clear-cut atherosclerotic plaques. In conclusion, careful assessments of cardiac function, morphology and activity need in patients with acromegaly.