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Background: The knowledge of various morphological & developmental anomalies of thyroid gland will help the surgeons in better planning of safe & effective surgery. Considering these facts we studied the variations of thyroid gland. Methods: The material for the present study was collected from the department of forensic medicine, MMC & RI, Mysore, which includes 56 male and 33 female adult postmortem cadavers aged between 18 to 80 years. A dissection was carried out to expose thyroid glands & variations were observed in the morphology of thyroid gland. Results: 1) 9% of specimens had agenesis of isthmus. 2) 46% of specimens had pyramidal lobe. 3) 41% of specimens had levator glanduli thyroidae. 4) 2.24 % of specimens had accessory thyroid tissue. Conclusion: This study highlights the various morphological anomalies of the thyroid gland which forms cornerstone to safe & effective surgery.

Functional imaging using radionuclide Tc99m pertechnetate is routinely used in the evaluation of the problems related to the thyroid gland. Scintiscan has been useful in the visualization of thyroid tissue in ectopic sites due to congenital developmental anomalies. Similarly, the scan helps in establishing the diagnosis of autonomously functioning nodule when the nodule being evaluated appears “hot” with suppression of rest of the gland activity. Here, we present a very rare case of autonomously functioning thyroid adenoma in an ectopic focus of accessory thyroid tissue in the mediastinum.

SUMMARY Accessory thyroid tissue was present either at the base of the neck or between the rami of the jaws in four of 17 normal adult goats. Six-and-a-half months after three of these four goats had been thyroidectomized the accessory tissues had disappeared in two and their 131 I-concentrating capacity had diminished greatly in the other. Residual or accessory thyroid tissue was found at the site of the original thyroid gland or in other sites 12 to 14 months after operation in 13 of 16 goats thyro-parathyroidectomized as immature animals.

1. Following thyroidectomy in guinea pigs, there is a gradual elevation of the surface tension of the blood plasma which reaches its height in from 19 to 22 days after operation. This elevation is probably permanent, since we have found it to persist for as long as 120 days. 2. In our experiments, we found a few thyroidectomized animals in which the surface tension of the plasma was still within normal limits 24 and 120 days after operation. We suggest that these exceptions are due to three possible factors: (1) incomplete thyroidectomy; (2) presence of accessory thyroid tissue; (3) compensatory activity on the part of other organs. 3. The surface tension of the plasma from operated animals is higher than that from controls in both the initial and 20 minute determinations, but the difference is greater at the 20 minute period. 4. The time-drop (difference between the initial and 20 minute determinations) is somewhat greater in the plasma from normal than in that from operated animals. 5. It is suggested that these changes are due to a decrease in the amount of certain normally occurring surface-active substances, the production of which is directly or indirectly dependent upon the thyroid gland.

In an asymptomatic 66-year-old woman presenting a systolic murmur in the pulmonic area, echocardiography evidenced a voluminous mass in the right ventricular outflow tract resembling a cardiac tumor. Histologic finding was that of aberrant normal thyroid. Although the occurrence of ectopic thyroid tissue in the heart is rare, it should be considered in the differential diagnosis whenever a mass is located at the level of the interventricular septum and encroaches on the right ventricular outflow tract. In these cases, a thyroid scintiscan may avoid an unnecessary surgical intervention. (Chest 1989; 96:424–25)