Parathyroid invasion, nodal recurrence, and lung metastasis by papillary carcinoma of the thyroid

Parathyroid Involvement by Thyroid Carcinoma: Results from a Single Institution and a Review of the Literature

Background and Objectives: Thyroid cancer (TC) is a common malignancy that accounts for approximately 1% of all human cancers. Given their anatomical proximity to the thyroid, the parathyroid glands (PTGs) are theoretically at risk of tumor involvement. However, PTG metastases are rare and may be underdiagnosed because of routine PTG preservation during thyroidectomy. This study aimed to identify cases of PTG invasion by TC through a 10-year retrospective review at Chosun University Hospital, along with an analysis of the existing literature. Materials and Methods: A total of 1032 thyroidectomy cases were reviewed, and PTG involvement was detected in 10 cases (0.97%). Clinicopathological characteristics were evaluated, and literature data were analyzed. Results: The affected patients included nine females and one male, with a mean age of 46 years (range: 25-77 years). Histological examination confirmed papillary thyroid carcinoma (PTC) in all cases. Tumor invasion into the perithyroid soft tissues was observed in nine patients, and central cervical lymph node metastases were present in four. All patients exhibited PTG Pattern A (direct invasion). Conclusions: Based on our findings and literature data, PTG involvement by TC has an incidence rate of 0.05-3.9%, predominantly affects women in their sixth to seventh decade of life, and appears to have no impact on prognosis unless accompanied by extensive extrathyroidal invasion. Further studies are necessary to determine whether PTG invasion should be integrated into the TNM staging system and to assess its prognostic and therapeutic implications.

Decoding the past and future of distant metastasis from papillary thyroid carcinoma: a bibliometric analysis from 2004 to 2023

Background

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, and its distant metastasis (PTCDM), although uncommon, seriously affects the survival rate and quality of life of patients. With the rapid development of science and technology, research in the field of PTCDM has accumulated rapidly, presenting a complex knowledge structure and development trend.

Methods

In this study, bibliometric analysis was used to collect 479 PTCDM-related papers published between 2004 and 2023 through the Web of Science (WoS) Core Collection (WoSCC) database. Keyword clustering analysis was performed using VOSviewer and citespace, as well as dual-map overlay analysis, to explore knowledge flows and interconnections between different disciplines.

Results

The analysis indicated that China, the United States, and South Korea were the most active countries in conducting research activities. Italy's research was notable due to its higher average citation count. Keyword analysis revealed that "cancer," "papillary thyroid carcinoma," and "metastasis" were the most frequently used terms in these studies. The journal co-citation analysis underscored the dominant roles of molecular biology, immunology, and clinical medicine, as well as the growing importance of computer science in research.

Conclusion

This study identified the main trends and scientific structure of PTCDM research, highlighting the importance of interdisciplinary approaches and the crucial role of top academic journals in promoting high-quality research. The findings not only provide valuable information for basic and clinical research on thyroid cancer but also offer guidance for future research directions.

Papillary Thyroid Cancer Metastases to the Parathyroid Gland

Introduction:

Papillary Thyroid cancer (PTC) is the most common malignancy encountered by endocrine surgeons accounting for up to 85% to 90% of all thyroid malignancies. Parathyroid metastases appear to be an uncommon phenomenon however are likely to be underdiagnosed due to routine parathyroid gland preservation during thyroidectomy.

Case:

We present the case of 63-year-old lady with PTC metastases to the parathyroid gland. She underwent total thyroidectomy, central compartment lymph node dissection and selective left neck (levels IIA-IV) lymph node dissection. Final pathology confirmed a 45 mm low grade conventional type papillary carcinoma with microscopic extension into perithyroidal soft tissue focally and into the adjacent left parathyroid gland.

Conclusion:

Parathyroid gland thyroid cancer infiltration/metastasis is rarely reported and likely underdiagnosed. This is the first case of parathyroid gland metastasis reported from New Zealand or Australia to our knowledge. There is currently limited research available to guide whether parathyroid gland infiltration or metastasis is of clinical or prognostic significance and whether a more aggressive treatment strategy is warranted when present.

Parathyroid gland involvement by thyroid cancer: results from a large series of thyroidectomies performed in two italian university hospitals and review of the literature

Objectives.Parathyroid involvement by thyroid cancer (TC) has not been frequently investigated in thyroidectomy-based studies. We aimed to detect cases of parathyroid invasion by TC in a large series of thyroidectomies and to review the literature on this topic. Study Design. A 10-yr period database research was made from the files of the Section of Pathology of two Italian University Hospitals. Out of 22,310 thyroidectomies, 10 patients with parathyroid involvement by TC were found. Results. The 10 patients, 7 females and 3 males, aged 55 ± 14 years (range 34-76, median 56) had papillary thyroid carcinoma and accounted for 0.4% of subjects affected by all TCs and submitted to thyroidectomy. The tumor invaded perithyroid soft tissues in 6 patients and central neck (level VI) lymph nodes in 3. Parathyroid involvement by TC occurred by infiltration in 6 cases, extension through an intervening pseudocapsule in 1, and both patterns in 3. All patients are alive and disease free at 5.6 ± 3-yr follow-up. Conclusion. Limited to thyroidectomy series, our results and literature data suggest that parathyroid involvement by TC has a 0.4-3.9% incidence rate; mainly affects women in their sixth-seventh decade of life; is associated to a good prognosis, unless massive extrathyroid extension of TC occurs.

Parathyroid involvement in thyroid cancer: an unforeseen event

Background

Parathyroid metastatic disease from thyroid cancer has not been studied extensively, mainly due to the need for parathyroid preservation during thyroid surgery.

Methods

We reviewed files from 1,770 patients with thyroid cancer followed up in our department and 10 patients with parathyroid metastases (0.5%) were identified. Patient and tumor characteristics were recorded.

Results

Six out of ten patients had metastases from papillary thyroid cancer, three from follicular thyroid cancer and one from anaplastic thyroid cancer. In nine patients parathyroid infiltration from thyroid cancer was found in direct contact with the thyroid cancer, and in one patient metastatic foci were observed not in continuity with the thyroid cancer.

Conclusions

Parathyroid involvement, although infrequent, may occur in thyroid cancer independently of patient age and tumor size. The clinical significance of such event is not clear. The influence on disease outcome remains to be elucidated.

Clinical significance of extrathyroid extension to the parathyroid gland of papillary thyroid carcinoma

Extrathyroid extension is a prominent prognostic factor of papillary thyroid carcinoma (PTC). In the UICC TNM classification, minimal extension to the sternothyroid muscle and perithyroid soft tissue is classified as T3 and further massive extension is classified as T4, the highest T grade. However, there have been few studies on the clinical significance of extension to the parathyroid gland in a large case series. In this study, we investigated the prognosis of PTC with extension to the parathyroid gland in a series of 3208 patients who underwent initial surgery between 1997 and 2004. Of these patients, 51 (1.6%) showed extension to the parathyroid gland on pathological examination. Twenty-one of these patients had massive extrathyroid extension to other adjacent organs corresponding to pT4. The remaining 30 were enrolled in this study. The disease-free survival (DFS) of these 30 patients was significantly better (p<0.0001) than that of pT4 patients and did not differ from that of patients showing minimal extrathyroid extension without extension to the parathyroid gland (p = 0.6264). Furthermore, none of these 30 patients died of carcinoma. Taken together, it is appropriate that extension to the parathyroid gland of PTC is graded as minimal extrathyroid extension (pT3), but not massive extension (pT4). Since minimal extension did not affect patient prognosis in our series, it is suggested that extension to the parathyroid gland has little clinical significance in PTC.

VEGF-D expression and lymph vessels play an important role for lymph node metastasis in papillary thyroid carcinoma

Papillary thyroid carcinoma frequently metastasizes to regional lymph nodes, and lymph node metastasis increases the risk of local regional relapse. Recent evidence suggests that vascular endothelial growth factor-D (VEGF-D) promotes lymphangiogenesis, which in turn promotes lymphatic metastasis. Therefore, the role of VEGF-D messenger RNA transcript levels and VEGF-D immunoreactivity in lymph node metastasis in papillary thyroid carcinoma was investigated. In addition, the role of blood vascular vessel, lymph vessel, and Flt-4-positive vessel densities were studied in relation to their suspected association with lymph node metastasis, and with VEGF-D expression. VEGF-D messenger RNA transcript levels by quantitative real-time reverse transcription-polymerase chain reaction and VEGF-D immunoreactivity by immunohistochemistry in 49 papillary thyroid carcinomas were also studied. This was followed by quantitative immunohistochemical staining for CD34, podoplanin, and Flt-4. Lymph node metastasis was significantly correlated with VEGF-D messenger RNA transcript levels (P=0.027) and VEGF-D immunoreactivity (P=0.019). Increased lymph vessel density was also correlated with VEGF-D expression and lymph node metastasis. In conclusion, our findings indicate that VEGF-D expression and increased lymph vessel density may have an important role for lymph node metastasis in papillary thyroid carcinoma.

Papillary carcinoma of the thyroid in Japan: subclassification of common type and identification of low risk group

AIMS

Papillary thyroid carcinoma (PTC) is classified into two subgroups-common type and other histological variants. Correlations between further subgrouping of the common type and patient prognosis are not well documented.

AIMS

To introduce two novel histological parameters to characterise PTC-loss of cellular polarity and loss of cellular cohesiveness. To investigate a new subgroup of common type PTC with possible prognostic value.

METHODS

In total, 213 patients with PTCs larger than 1 cm were studied. Histological characteristics of these PTCs, including tumour growth pattern, encapsulation, extrathyroidal invasion, loss of cellular polarity, and loss of cellular cohesiveness were examined and correlated with disease free survival (DFS).

RESULTS

Multivariate analysis revealed that invasive growth of unencapsulated PTC, in addition to sex (male) and tumour size (>4 cm) were significant and independent parameters for poor DFS, whereas loss of cellular polarity and cohesiveness, old age (>60 years), extrathyroid invasion, and completeness of surgery were significant only in univariate analysis. PTCs that showed expansive growth and retained cellular polarity had a favourable course, with no recurrence and no cancer related deaths. In contrast, PTCs exhibiting loss of cellular polarity and/or invasive growth with no tumour capsule had a higher risk of recurrence.

CONCLUSION

Cytological features alone cannot predict patient outcome in PTC. This study indicates for the first time that loss of cellular polarity and the tumour growth pattern are useful parameters for identifying the so called low risk group in common type PTC and in predicting patient outcome in terms of tumour recurrence and cancer related death.