Clinical characteristics of papillary thyroid carcinoma arising from the pyramidal lobe

A Rare Case of Double Pyramidal Lobe of the Thyroid Gland

The pyramidal lobe is an anatomical component of the thyroid gland seen in up to 65% of individuals. It represents the distal, nondegenerate part of the thyroglossal duct. The double pyramidal lobe is a very rare occurrence, and this is the first reported case in Sri Lanka. A 40-year-old woman presented a long-standing goiter. Her evaluation revealed a benign multinodular goiter with a dominant right colloid nodule and background thyroiditis. She was euthyroid and had no compressive symptoms. Considering cosmesis, the patient opted for total thyroidectomy during which two pyramidal lobes were identified. The rest of the thyroid gland and the parathyroids had no anomalies. After an uneventful postoperative stay, she was discharged later. This is a very rare case where the patient had two separate pyramidal lobes; a phenomenon documented in less than 10 cases around the world. In addition to embryology, the pyramidal lobe has significance in clinical practice. It can be associated with benign and malignant disease of the thyroid; focal and diffuse. Incomplete removal may result in recurrence of the disease in the remaining thyroid tissue of the pyramidal lobe. Therefore, active inspection of the lobe including its anatomy during thyroid surgery and complete excision when indicated is of paramount importance.

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.

Isolated Papillary Thyroid Carcinoma of the Pyramidal Lobe: A Case Report and Review of Literature

The pyramidal lobe (PL) represents an embryological remnant of the thyroglossal duct. A solitary focus of papillary thyroid carcinoma (PTC) of the PL of thyroid gland is a rare entity. We present a case of a 33-year-old woman with PTC of the PL with lymph nodal involvement and further discuss the lines of surgical management for primary PTC arising from the PL of thyroid gland.

PIWIL1 Promotes Malignant Progression of Papillary Thyroid Carcinoma by Inducing EVA1A Expression

INTRODUCTION

Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid cancer. Previous studies have reported on the ectopic expression of P-element-induced wimpy testis ligand 1 (PIWIL1) in various human cancers, but its role in PTC progression has not been investigated.

METHODS

In this study, we measured the expression levels of PIWIL1 and Eva-1 homolog A (EVA1A) in PTC using qPCR and WB. We performed a viability assay to evaluate PTC cell proliferation and used flow cytometry to investigate apoptosis. Moreover, we conducted a Transwell invasion assay to quantify cell invasion and assessed PTC growth in vivo using xenograft tumor models.

RESULTS

Our findings showed PIWIL1 to be highly expressed in PTC and promote cell proliferation, cell cycle activity, and cell invasion, while suppressing apoptosis. Additionally, PIWIL1 accelerated tumor growth in PTC xenografts by modulating the EVA1A expression.

CONCLUSION

Our study suggests that PIWIL1 contributes to the progression of PTC through EVA1A signaling, indicating its potential role as a therapeutic target for PTC. These results provide valuable insights into PIWIL1 function and may lead to more effective treatments for PTC.

Pyramidal lobe-dominant papillary thyroid carcinoma-A rare entity with important clinical implications

Papillary thyroid carcinoma (PTC) primarily located in the pyramidal lobe of the thyroid gland is extremely rare, therefore the clinical and pathological features are not well understood. The authors describe a case of PTC of the pyramidal lobe, in a 77-year-old woman who underwent en bloc total thyroidectomy with pyramidal lobe, hyoid bone and cervical lymph node excision. In line with the present case, current literature reports a greater presence of worse prognostic factors, namely extrathyroidal extension, advanced T stage or presence of cervical lymph node metastasis. Recently, a new classification has been suggested-Upper Neck Papillary Thyroid Cancer (UPTC)-which encompasses these carcinomas, Delphi ganglion metastases and thyroglossal duct cyst carcinomas, with potential clinical and therapeutic implications, particularly the need for orthotopic thyroidectomy. Also, the complete excision of the pyramidal lobe during thyroidectomy may influence the success of radioactive iodine therapy and the patient's follow-up surveillance.

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.

Residual Pyramidal Lobe Increases Stimulated Thyroglobulin and Decreases Endogenous Thyroid Stimulating Hormone Stimulation in Differentiated Thyroid Cancer Patients

OBJECTIVE

To determine the frequency of pyramidal lobe remnants after total thyroidectomy (TT) and the effect on stimulated thyroglobulin (Tg).

METHODS

The study included 1740 differentiated thyroid cancer (DTC) patients who were followed up by our center. The department database was searched to identify DTC patients with residual pyramidal lobe after TT. All postoperative technetium-99m pertechnetate thyroid scintigraphy images were re-evaluated for pyramidal lobe residue. Serum stimulated Tg and thyroid stimulating hormone (TSH) levels measured within the first 6 months after TT were retrieved from the database.

RESULTS

Pyramidal lobe residue was detected in 10.4% of the patients who underwent TT. Evidence of the pyramidal lobe was present on preoperative ultrasonography in 1.6% of the patients with residual pyramidal lobe. Stimulated Tg in patients with pyramidal lobe residue was significantly higher than that in patients without residue (P = .01). Endogenous stimulated TSH in patients with residual pyramidal lobe was significantly lower than that in patients without residue (P = .036). In 5.7% of patients with pyramidal lobe residue, a TSH level of >30 mIU/L was not achieved, which was a significantly higher rate than that in patients without pyramidal lobe residue (P = .034) and is the level required for maximum radioiodine uptake.

CONCLUSION

Pyramidal lobe residue was found in almost 10% of DTC patients. The pyramidal lobe is often missed on preoperative ultrasonography. Residual pyramidal lobe increased stimulated Tg and decreased endogenous stimulated TSH. Residual pyramidal lobe may complicate the follow-up of DTC patients.

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.