Thyroid Research and Practice

CASE REPORT
Year
: 2016  |  Volume : 13  |  Issue : 1  |  Page : 25--26

Double pyramidal lobe of thyroid gland: A rare presentation


Arsheed Hussain Hakeem1, Imtiyaz Hussain Hakeem2, Fozia Jeelani Wani3,  
1 Department of the Head and Neck Oncology, Apollo Cancer Hospitals, Hyderabad, Telangana, India
2 Department of Internal Medicine, Poplar Bluff Regional Medical Center, Poplar Bluff, Missouri, USA
3 Department of Gynaecology and Obstetrics, Apollo Hospitals, Hyderabad, Telangana, India

Correspondence Address:
Arsheed Hussain Hakeem
Apollo Cancer Hospitals, Jubilee Hills, Hyderabad - 500 096, Telangana
India

Abstract

Knowledge of the variations of the pyramidal lobe of the thyroid assumes importance as it has direct implications on the outcome of the primary surgery and on the postoperative radioiodine ablation. If not recognized and completely removed at the time of initial thyroid surgery, it may be site of residual/recurrent disease and also may interfere with the efficient radioiodine ablation postoperatively. We report a unique case of the double pyramidal lobe of thyroid gland in an operated woman with papillary carcinoma thyroid. Our literature search revealed only one documented case of the double pyramidal lobe. Knowledge and recognition of such a variation is highly useful for clinicians to perform safer and effective thyroid surgery.



How to cite this article:
Hakeem AH, Hakeem IH, Wani FJ. Double pyramidal lobe of thyroid gland: A rare presentation.Thyroid Res Pract 2016;13:25-26


How to cite this URL:
Hakeem AH, Hakeem IH, Wani FJ. Double pyramidal lobe of thyroid gland: A rare presentation. Thyroid Res Pract [serial online] 2016 [cited 2022 Dec 8 ];13:25-26
Available from: https://www.thetrp.net/text.asp?2016/13/1/25/168887


Full Text

 Introduction



Apart from the right and the left lateral lobes of the thyroid gland, there is a projection of thyroid tissue that extends superiorly from the isthmus and is known as the pyramidal lobe. The pyramidal lobe is related to the distal portion of the thyroglossal duct, which develops along the migratory path of the thyroid gland and usually disappears later in the development.[1] Different authors have different views regarding the pyramidal lobe as some consider it as anomaly, while others consider it as morphological variation and most are of the view that it is normal component of the thyroid gland.[1],[2] If pyramidal lobe is not recognized and removed completely at the time of total thyroidectomy for benign and malignant lesions, it may be a source of recurrent disease.[1],[2] Its complete removal is also of significance for the successful postoperative radioactive iodine ablation, as the therapeutic benefit will be reduced as residual pyramidal lobe will absorb most of the radioactive agent.[3],[4] Literature is full of variations as regard to its presence, position and extent of pyramidal lobe. However, by an extensive search of the English language literature on pyramidal lobe, we found only one documented report of double pyramidal lobe.[5] The aim of this case report was to present a unique case of the double pyramidal thyroid lobe in an operated woman with papillary carcinoma thyroid. Knowledge of such a variation that is a double pyramidal is highly useful for clinicians to explore the possibility of its occurrence in order to perform a safer and more effective thyroid surgery.

 Case Report



A 56-year-old woman was operated for a papillary carcinoma thyroid. Preoperatively, ultrasonographic (USG) examination had shown a 4 cm × 5 cm solid nodule in the left thyroid lobe. Fine needle aspiration cytology was in favor of papillary thyroid cancer. USG was not useful in detecting pyramidal lobes preoperatively. She was planned for total thyroidectomy and during the procedure double pyramidal lobe was detected. Careful dissection was done starting from isthmus to the hyoid bone. Two pyramidal lobes were identified and carefully dissected and followed to the hyoid bone. Whole of the thyroid gland and both the pyramidal lobes were resected in continuity and too [Figure 1], with preservation of all the parathyroids and bilateral recurrent laryngeal nerves. Postoperative period was uneventful. Histopathology was in favor of classic papillary carcinoma with normal thyroid tissue in the both pyramidal lobes.{Figure 1}

 Discussion



Most of the variations in the thyroid gland are due to persistence of the thyroglossal duct or tract. The most common example of this persistence is the pyramidal lobe. The pyramidal lobe of the thyroid gland varies in shape, size, position, as well as appearance. The prevalence of pyramidal lobe has been reported in 12–65% of cases in various studies on either cadaveric or operative surgical specimens.[1],[2] Pyramidal lobe can be a potential site of primary localization of a solitary or multifocal malignant thyroid cancer.[3] It can also be a site of recurrent thyroid disease after total thyroidectomy.[3] Remnant pyramidal is a frequent site for recurrence of benign diseases after total and subtotal resection of the thyroid gland.[6],[7],[8] It may result in inefficient postoperative radioiodine ablation as it may take up the most of isotope administered to the patient.[9] Knowledge about its anatomic and morphologic variations is necessary for safe and effective thyroid surgery.

Our literature search revealed only one such case of double pyramidal lobe.[5] The purpose of case report was to add a rare variation of the pyramidal lobe and to emphasize the necessity and importance of exploration of the visceral compartment of the neck and resection of this structure during primary operations on the thyroid. Therefore, the possibility of identifying the pyramidal lobe should not be ignored during surgery as it often remains unvisualized during preoperative imaging studies. This means it needs to be actively sought and identified during surgery, more so if the patient is undergoing total thyroidectomy for differentiated thyroid carcinoma. Apart from decreasing the chance of local recurrence in benign disease, it ensures complete thyroid tissue removal in the well differentiated carcinoma that often can be multifocal.[10] Complete removal of the pyramidal lobe also makes postoperative radio iodoine ablation effective and increases the sensitivity of serum thyroglobulin as tool for follow-up.[10]

The possibility of identifying a pyramidal lobe should be always kept in mind and knowledge of various positions, size, and number are of significance. It should always be examined during thyroid surgery and removed completely in total and subtotal thyroidectomy.

References

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