ABSTRACT
Introduction: Being a highly vascular and one of the essential endocrine glands, the knowledge of the variationsin the morphology of the thyroid gland stands an important role with respect to their identification, isolation orpreservation, and prevention of any untoward complication during the surgeries around the neck region, thusincreasing the chances of favourable surgical outcome.Aim: The aim of the present study was to identify the frequent variants in the structure of the thyroid gland, andto compare the same with the work of other authors.Materials and Methods: The present study was conducted on total 86 thyroid glands with morphological variations,out of which 42 were of males and 44 were of females. These were obtained during routine dissection of the neckin the adult human cadavers aged above 50 years.Results: The most common variation in the present study was the presence of pyramidal lobe (50% in males and65.9% in females), followed by the levator glandulae thyroidae (45.2% in males and 52.3% in females), absenceof the isthmus (7.1% in males and 20.5% in females), accessory thyroid tissue (2.4% in males and 2.8% infemales), and the least common was presence of groove in the thyroid tissue (0% in males and 2.8% in females).There were also combination of variants in some thyroids.Conclusion: The study emphasizes on the common anatomical variations in the thyroid gland morphology andtheir surgical correlations.
ABSTRACT
Introduction: The morphological variations of the thyroid gland are not an uncommon phenomenon and may due to embryological remnant or non-specific development of different parts of it. Prior anatomical knowledge of these variations is of immense importance to prevent catastrophies during or after thyroid surgeries. Therefore, in this study we aimed to investigate the prevalence of morphological variations of the thyroid glands in north Indian cadavers. Subjects and Methods: This study was conducted on 50 formalin embalmed adult human cadavers aging between 40–65 years, of which 40 were males and 10 were females. Thyroid glands were dissected and examined properly for the presence of pyramidal lobe, levator glandulae thyroidae, accessory thyroid tissue and complete absence of isthmus. Results: The pyramidal lobe was present in 9 (18%) and frequently arising from the right side of the isthmus. LGT was found in 7 (14%) and almost in all cases it was extending from the apex of the pyramidal lobe to the hyoid bone. Only 2 (4%) cadavers did not show an isthmus while accessory thyroid tissue was found only in one case. Morphological variations were more common in females than in males and the difference was statistically significant (p value<0.05). The means of all measured parameters were higher in female than in male but these gender differences were not significant (p>0.05). Conclusion: Morphological variation of the thyroid gland is a common phenomenon, particularly in female. Hence it requires proper detection and documentation prior to any thyroid surgery, so that iatrogenic catastrophies can be avoided
ABSTRACT
Introduction: The thyroid gland is an important endocrine gland in human body , thyroid disorder being thecommon health problem affecting almost 5% of the population. Incomplete removal of thyroid gland may causerecurrence of disease and it could be dangerous when complete removal of gland tissue is indicated in Grave’sdisease or malignant carcinoma . Remains of pyramidal lobe ,the cause. Hence its necessary to know the trueincidence of anatomic variants of thyroid viz , pyramidal lobe or levator glandulae thyroidae to perform safeand effective surgery.Aims: To study the morphological variations of lobes of thyroid gland . viz. pyramidal lobe, levator glandulaethyroidae and its incidence in western maharashtra population.Materials and methods: The study was conducted on total of 60 thyroid glands(male-34, female-26) collectedduring routine dissection from adult cadavers of both sexes aged more than 18 yrs in the department of anatomy,B. J. government medical college , Pune. A cross sectional descriptive type of study was performed.Results: Pyramidal lobe was found in 25% cases , more common in females (30.76%), than males (20.58%) .Levator glandulae thyroidae was seen in (38.33%) cases, more common in females (38.46%) than males (38.23%). Pyramidal lobe was mostly originated from center of isthmus (46.6%) and least from right end of isthmus(6.66%) . In pyramidal lobe, length and breadth were more in males whereas thickness was more in females.Maximum 73.9% LGT seen were muscular in texture followed by fibromuscular , fibrous respectively. Maximumnumber of LGT seen were extending from pyramidal lobe to hyoid bone (43.47%), followed by either lobe ofthyroid gland to hyoid bone . All dimentions of LGT were more in males. PL associated with LGT was seen in23.33% cases , males 20.59% and females 26.92% , thus showing female preponderance.Conclusion: The study highlights the incidence of pyramidal lobe and levator glandulae thyroidae which isimportant to keep in mind for successful thyroid surgeries to prevent recurrence of diseases .
ABSTRACT
Because of its embryonic origin, the thyroid gland is predisposed to multiple anatomical variations and developmental anomalies. These include the pyramidal lobe, the origin of levator glandular thyroidae, the absence of the isthmus, ectopic thyroid, accessory thyroid tissues, etc. These anatomical variations are clinically significant to surgeons, anatomists, and researchers. The present study was designed to report anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population. The study was conducted on 40 cadavers used for routine dissection classes. The thyroid gland was exposed and observed for any variations and developmental anomalies. The length, width, and thickness of the lobes were measured using a vernier caliper. Differences in the incidence of pyramidal lobe and absence of the isthmus between sexes were tested using a Pearson chi-square test. The mean length, width, and thickness of the right lobe were 4.24 cm, 1.8 cm, and 1.6 cm, respectively, whereas it was 4.08 cm, 1.8 cm, and 1.6 cm, respectively for that of the left lobe. The pyramidal lobe was noted in 52.5% of the cadavers. The levator glandulae thyroidae were prevalent in 40% of the cadavers. The isthmus mainly overlies the 2nd to 4th tracheal rings and was absent in 7.5% of the cadavers. Accessory thyroid tissue and double pyramidal lobes were noted in 2.5% of the cadavers. Most of the variations of the thyroid gland were seen frequently in female but it was not statically significant. Different clinically important and rare variations of the thyroid gland were found.
Subject(s)
Female , Humans , Anatomists , Cadaver , Incidence , Surgeons , Thyroid Dysgenesis , Thyroid GlandABSTRACT
The variety of multiple morphological variations in the thyroid gland is found as a result of disturbed organogenesis in humans as agenesis, hypoplasia, accessory, ectopy and hemiagenesis. In the routine undergraduate dissection of the thyroid gland, multiple anomalies of the thyroid gland were encountered in 50 and 60 years old female and male cadaver respectively. These were in form of absent isthmus with accessory thyroid lobe in between two lateral lobes, pyramidal lobe arising from left lobe of thyroid with levator glandulae thyroidae in first case. Second case showed narrow isthmus related to first tracheal ring and levator glandulae thyroidae arising from left lobe. In these case studies, we highlight various developmental anomalies of the thyroid gland as absent isthmus, pyramidal lobe and accessory lobe with levator glandulae thyroidae. Hence a thorough knowledge of such morphological variations of thyroid gland helps the surgeons in better planning of safe, effective and uncomplicated operative procedures in resection of thyroid and tracheotomy procedures.