Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

Cine clips increase the detection of thyroid pyramidal lobe in routine thyroid sonogram

Background

Identification and resection of the thyroid pyramidal lobe is important for thyroid cancer surgery in order to prevent interval cancer in residual thyroid tissue.

Purpose

The purpose of this study was to determine how often a thyroid pyramidal lobe is found in patients with and without previous thyroidectomy and to optimise the protocol for identifying thyroid pyramidal lobes during routine thyroid ultrasonography.

Material and Methods

In this prospective study, a total of 1579 patients who received routine thyroid ultrasound scans at a single centre were enrolled. A dedicated standard scanning protocol was established containing both static images of the anterior neck superior to the thyroid as well as a transverse cine loop starting from the isthmus to the hyoid bone. The presence and features of thyroid pyramidal lobes were evaluated and compared.

Results

Detection rate of thyroid pyramidal lobes in patients without thyroidectomy improved from 39.5% (480/1215) to 49.7% (640/1215) with protocol adding cine-loop as compared to protocol without cine-loop. The cine-loops were particularly helpful in the detection of thyroid pyramidal lobes when it is separated from the main lobe or in thyroidectomy patients. By adding assessment with cine-loop into the dedicated protocol, we have further detected different pathologies occurring on thyroid pyramidal lobes including benign and malignant solid nodules and pseudo-nodules of Hashimoto's thyroiditis.

Conclusion

The addition of dynamic assessment with cine-loop increases the detection rate of thyroid pyramidal lobes. By paying attention to the thyroid pyramidal lobe in pre-operative diagnostic sonographic images, we can help to avoid incomplete removal of the thyroid gland during thyroidectomy.

Recurrence of papillary thyroid carcinoma from the residual pyramidal lobe: a case report and literature review

RATIONALE

Recurrence of papillary thyroid carcinoma (PTC) usually requires a second operation, which carries a high complication rate, especially if central neck dissection (CND) is necessary. Recurrent PTC from pyramidal lobe is a rare entity, which is mainly due to non-standardized operation. However, literature on this topic is limited.

PATIENTS CONCERNS

Here, we present a case of a 46-year-old woman with the recurrence of PTC from the thyroid pyramidal lobe (PL) following two thyroid operations.

DIAGNOSES

The final pathological result revealed recurrent PTC from the residual pyramidal lobe tissue.

INTERVENTIONS

The resection of the residual PL, the pretracheal nodes and the Delphian nodes plus intraoperative neuromonitoring (IONM) were performed, followed by TSH suppression therapy.

OUTCOMES

After two previous operations, the recurrent PTC from the residual pyramidal lobe tissue was completed resected. Until the latest follow-up, the patient had an excellent response to the third intervention.

LESSONS

Complete excision of the PL is mandatory in patients with PTC if thyroid surgery was indicated, considering the potential risk of recurrence from the PL and the high incidence of multifocality of PTC.

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.