Follicular carcinoma arising from the pyramidal lobe of the thyroid

Ultrasound for the detection of the pyramidal lobe of the thyroid gland

PURPOSE

The pyramidal lobe (PL) is an ancillary lobe of the thyroid gland that can be affected by the same pathologies as the rest of the gland. We aimed to assess the diagnostic performance of high-resolution sonography in the detection of the PL with verification by dissection and histological examination.

METHODS

In a prospective, cross-sectional mono-center study, 50 fresh, non-embalmed cadavers were included. Blinded ultrasound examination was performed to detect the PL by two investigators of different experience levels. If the PL was detected with ultrasound, dissection was performed to expose the PL and obtain a tissue sample. When no PL was detected with ultrasound, a tissue block of the anterior cervical region was excised. An endocrine pathologist microscopically examined all tissue samples and tissue blocks for the presence of thyroid parenchyma.

RESULTS

The prevalence of the PL was 80% [40/50; 95% CI (68.9%; 91.1%)]. Diagnostic performance for both examiners was: sensitivity (85.0%; 42.5%), specificity (50.0%; 60.0%), positive predictive value (87.2%; 81.0%), negative predictive value (45.5%; 21.0%) and accuracy (78.0%; 46.0%). Regression analysis demonstrated that neither thyroid parenchyma echogenicity, thyroid gland volume, age nor body size proved to be covariates in the accurate detection of a PL (p > .05).

CONCLUSION

We report that high-resolution ultrasound is an adequate examination modality to detect the PL. Our findings indicate a higher prevalence than previously reported. Therefore, the PL may be regarded as a regular part of the thyroid gland. We also advocate a dedicated assessment of the PL in routine thyroid ultrasound.

Thyroid neoplasm in Makkah region, Saudi Arabia. A retrospective epidemiological study

Objectives:

To improve our local data and demographics of thyroid neoplasm in Makkah region, Kingdom of Saudi Arabia and provide some basic statistics for future studies in our local community.

Methods:

A record based retrospective epidemiological study was conducted and included 314 thyroid disease patients who were presented to our centers at Makkah region, Kingdom of Saudi Arabia between December 2009 and December 2019.

Results:

A descriptive statistical analysis was carried out. The average age was 42.77 years, with a female-to-male ratio of 3:1, and most of the patients were Saudi (77%). Fifty-seven percent of cases were benign, while in malignant cases, 33.4% were papillary thyroid carcinoma. The mean follow-up time was 15.44 months, with excellent compliance in 39.4% of the patients.

Conclusion:

Thyroid tumors have a leading incidence in head and neck tumors in Makkah, Kingdom of Saudi Arabia, mandating further studies to determine the causes and distribution in other regions of the country.

Clinical characteristics of papillary thyroid carcinoma arising from the pyramidal lobe

PURPOSE

Papillary thyroid carcinoma (PTC) arising from the pyramidal lobe is rare; therefore, clinicopathologic evaluation is lacking. In addition, the rate of occult malignancy in the pyramidal lobe after thyroid surgery is unclear. This study is to evaluate the clinical characteristics of PTCs that involve the pyramidal lobe.

METHODS

The study enrolled 1,107 patients who underwent thyroid surgery for PTC at Seoul National University Hospital from 2006 to 2015. Pyramidal lobe status in pathologic reports was clear in all cases. "Pyramidal lobe-dominant PTC" was defined as single pyramidal lobe cancer or multifocal cancer with larger pyramidal lobe tumor. "Incidental pyramidal lobe PTC" was defined as occult cancer identified after thyroidectomy or as multifocal cancer with smaller pyramidal lobe tumor.

RESULTS

Ten patients were included in the pyramidal lobe-dominant PTC group. The mean age was 58 ± 12.5 years, and the mean tumor size was 0.7 ± 0.7 cm. Cervical lymph node metastasis was found in 5 patients (50%). Three patients had microscopic lymphatic invasion, and 7 had advanced American Joint Comitee on Cancer (AJCC) stage disease (5 with stage III and 2 with stage IV). Compared with conventional PTC (n = 1,058), pyramidal lobe-dominant PTC was significantly associated with lymphatic invasion (P = 0.031) and advanced AJCC stage (P = 0.022). The prevalence of incidental pyramidal lobe PTC was 3.56%.

CONCLUSION

Pyramidal lobe PTC is relatively small in size; however, the rate of extrathyroidal extension and lymph node metastasis is high. Preoperative evaluation of nodal status is important, and the extent of surgery should be determined in accordance with the preoperative diagnosis.

Surgical anatomy of the pyramidal lobe in cancer patients: A Prospective Cohort in a Tertiary Centre

INTRODUCTION

To study the characteristics of pyramidal lobe (PL) in cancer patients with emphasis on its involvement in patients subjected to thyroidectomy at a tertiary care cancer centre.

METHODS

Retrospective review of prospectively maintained data of 103 patients (33 males and 70 females) who underwent thyroidectomy from January 1st 2011-August 31st 2013. Surgery was performed by single surgeon, findings recorded by the lead author and all measurements taken with specimen in situ prior to mobilization of thyroid gland with intact anatomy. Thyroid specimens were examined for presence, location, length and histology of PL.

RESULTS

PL was identified in 38 (36.89%) patients. PL was commoner on left 27 (71.05%) compared to 11 (28.95%) on right side. The frequency of PL was higher in males 51.51% compared to females 30%. The length varied from 4 to 35 mm. The mean length was 18.0 ± 12.4 mm. In 10.53% cases PL contained deposits of papillary carcinoma of thyroid.

DISCUSSION

Meticulous clearance of disease is of utmost importance in thyroid cancer surgery in order to prevent recurrence and ensure reliable follow up with serum thyroglobulin. PL is a common site of residual thyroid tissue which if involved by cancer can be a cause of local recurrence.

CONCLUSIONS

PL is a well established entity which is present in over one third of patients. Efforts should be made to identify PL during surgery given its bearing on the management of thyroid carcinoma as nearly 10% of these will be site of multifocal papillary carcinoma.

Comparison between ultrasonography and computed tomography for detecting the pyramidal lobe of the thyroid gland: a prospective multicenter study

Objective

To compare the detection rates of the pyramidal lobe of the thyroid gland (TPL) using ultrasonography (US) and computed tomography (CT) in a prospective multi-center study.

Materials and Methods

We enrolled 582 patients who underwent neck CT at six institutions. Each radiologist prospectively evaluated the presence and features of TPLs on thyroid US. Radiologists were divided into two groups according to their previous experience in detecting TPL on US or CT. The same radiologist also retrospectively assessed CT findings, blinded to the corresponding US findings.

Results

The pyramidal lobe of the thyroid glands were detected in 230 cases (39.5%) on US and in 276 cases (47.6%) on CT. The TPL detection rate at the six institutions ranged from 22.0% to 59% for US and from 34.1% to 59% using CT. There were significant differences between US and CT in the detection rate, length, anteroposterior diameter, volume, and superior extent of TPL (p ≤ 0.027). The TPL detection rates on both US and CT (p < 0.001) differed significantly according to the experience level of the radiologists. When the CT result was used as a reference standard, the sensitivity, specificity, positive and negative predictive values, as well as the accuracy of US for TPL detection were 72.6%, 91.5%, 89.3%, 77.3%, and 82.1%, respectively.

Conclusion

Our prospective multicenter study revealed that US could detect TPL with relatively high diagnostic accuracy compared to CT. Because the detection rate of TPL varied significantly according to the radiologists' level of experience, careful inspection is necessary to avoid imaging pitfalls and ensure appropriate evaluation of TPL on both US and CT.

Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid Epub ahead of print pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

Pyramidal lobe decreases endogenous TSH stimulation without impact on radio-iodine therapy outcome in patients with differentiated thyroid cancer

OBJECTIVES

The aim of the study was to assess the frequency of pyramidal lobe (PL) detected in iodine-131 (I-131) scans of thyroid bed in patients after thyroidectomy for differentiated thyroid cancer (DTC) and to investigate influence of PL on endogenous thyrotropin (TSH) stimulation as well as on the effects of the radio-iodine ablation in one-year follow-up.

PATIENTS AND METHODS

This study was designed as a retrospective analysis of 302 radio-iodine neck scans of patients thyroidectomized due to DTC. The study population was selected from patients with PL detected in thyroid bed scintigraphy. Patients without PL were included to the control group. The study and the control groups did not differ in age, sex of patients, histological type and stage of the DTC.

RESULTS

Pyramidal lobes were found in 30.5% of all patients. Patients in the study group underwent repeat surgery more often than controls without PL. Preablative TSH level in patients with PL was statistically lower than in the control group, in contrast to free thyroid hormones, which were higher in patients with PL. Preablative and postablative TSH-stimulated thyroglobulin (Tg) and antibodies against thyroglobulin (TgAbs) were measured in both groups, and comparison did not reveal differences. Moreover, for the per-patient analysis, sites of uptake in whole body scintigraphy performed 1 year after radio-iodine remnant ablation (RRA) did not differ between the study and the control groups.

CONCLUSION

Pyramidal lobe decreases endogenous TSH stimulation without impact on radio-iodine therapy outcome in patients with DTC.

Pre-operative detection of thyroid pyramidal lobes by ultrasound and computed tomography

This study aimed to assess the diagnostic accuracy of pre-operative ultrasound (US) and computed tomography (CT) for detecting thyroid pyramidal lobe (TPL). A single radiologist prospectively performed thyroid US and retrospectively reviewed neck CT to detect TPLs in 135 consecutive patients scheduled for thyroid surgery. The location, size and superior extent of each TPL and its separation or continuity with the main thyroid gland were assessed by thyroid US, neck CT and surgery. The prevalence of TPLs as diagnosed by thyroid US, neck CT and surgery was 58.5% (79/135), 56.3% (76/135) and 60% (81/135), respectively. We compared US and CT detection of TPLs with surgical data to determine their sensitivity (85.2% and 91.4%), specificity (81.5% and 94.4%), positive (87.3% and 96.1%) and negative (78.6% and 87.9%) predictive values and accuracy (83.7% and 92.6%). For detecting TPLs, both neck CT and thyroid US have good diagnostic value, although neck CT is more accurate than thyroid US.

Detection of thyroid pyramidal lobe by ultrasound versus computed tomography: a single-center study

OBJECTIVE

The prevalence and features of the thyroid pyramidal lobe (TPL) on computed tomography (CT) have been reported, but no ultrasound (US) study has been found. The purposes of the current study were to assess the sonographic prevalence and features of TPLs and to compare the US and CT parameters of TPLs.

METHODS

From November 2012 to February 2013, a total of 160 patients who were scheduled for surgical treatment of thyroid cancers and follicular neoplasms were enrolled. A single radiologist prospectively evaluated the presence and features of TPLs on preoperative thyroid US, noting the size, location, degree of continuity with the main thyroid gland, and superior extent of each TPL. On a different day, the same radiologist retrospectively evaluated CT findings in the same patients from a picture archiving and communication system.

RESULTS

Ultrasound revealed TPLs in 82 cases (50.6%) and CT revealed TPLs in 96 cases (59.3%). Thyroid pyramidal lobes predominantly originated from the left thyroid lobe on both US (34/82, 41.5%) and CT (40/96, 41.7%). The mean length, anteroposterior diameter, transverse diameter, and volume of the TPLs were 20.9 mm, 2.0 mm, 5.8 mm, and 268.6 mm on US and 22.8 mm, 1.9 mm, 6.1 mm, and 344.0 mm on CT, respectively. When CT findings were used as the reference standard, the sensitivity, specificity, positive and negative predictive values, as well as accuracy of US for detecting TPLs were 82.3, 95.3, 93.3, 78.2, and 87.5%, respectively.

CONCLUSIONS

Like neck CT, thyroid US may be useful in evaluating TPLs.

Lymphatic drainage, regional metastases and surgical management of papillary thyroid carcinoma arising in pyramidal lobe--a single institution experience

Papillary thyroid carcinoma (PTC) arising in pyramidal lobe (PL) is very rare. The aim of this study was to determine the incidence of single PTC focus in PL and its lymphonodal metastases, as well as to present a single surgeon experience in management of PL PTC. We performed a retrospective analysis of records of all patients surgically treated for PTC in our institution from year 2003 to 2013. Only patients with single PTC focus in PL were included. Out of total 753 patients, majority (66.52%) had PTC focus in one of the lobes, while only 3 patients (0.4%) had solitary PTC focus in PL. They were all females, aged 36, 41 and 22. During surgery, methylene-blue dye was injected peritumorally. After frozen section analysis of excised PL and isthmus and confirmation of malignancy, we performed total thyroidectomy with central neck dissection, as well as sentinel lymph node biopsy in both jugulo-carotid regions. Pathology showed encapsulated PTC stage T1 and solitary metastasis in Delphian lymph node of the youngest patient. All patients were disease free in the follow-up. PTC single focus in PL is very rare and only individual experiences can be discussed regarding the extent of the surgery.

Scintigraphic evaluation of thyroid pyramidal lobe

Objective: The aim of this study is to investigate the presence of pyramidal lobe in thyroid scintigraphy and to compare the presence of pyramidal lobe in different thyroid pathologies between genders.

Methods: Images of 866 patients (663 female, 203 male) with ages ranging from 8 to 85 were evaluated retrospectively. Presence of pyramidal lobe and its location were established in images. Patients were divided into groups in terms of gender, presence of nodular/diffuse goiter, thyroid function test results and rate of the presence of pyramidal lobe and whether a significant difference existed between the groups were calculated.

Results: Of the 866 patients, 156 (18%) had pyramidal lobe observed in scintigraphy. Hundred and 26 (81%) of patients observed to have pyramidal lobe were female and 30 (19%) were male. Pyramidal lob stemmed from the left lobe in 76 (48%) patients, right lobe in 61 (40%) patients, and isthmus in 19 (12%) patients. Pyramidal lobe visualization rate was 18% for euthyroidism and hyperthyroidism, it was found as 15% for hypothyroidism. The rate of pyramidal lobe visualization was 13% in nodular goiter patients, 43% in diffuse goiter patients, and 20% in patients whose scintigraphy showed normal thyroid glands. In the statistical evaluation, rate of pyramidal lobe visualization in diffuse goiter patients was found to be significantly higher compared to other patients (p<0.001).

Conclusion: Preoperative imaging of pyramidal lobe especially in patients requiring total thyroidectomy would decrease relapses that may occur later and thus facilitate the treatment and monitoring of patients.

Conflict of interest:None declared.