Papillary thyroid carcinoma: occurrence and types of lymph node metastases

Papillary thyroid microcarcinoma (Black Ink)

We report a case of a 58-year-old Caucasian woman affected by papillary thyroid microcarcinoma (PTMC) of the left-lobe of the gland with very small size (Ø 0.3 cm). The characteristics with the Diagnostic Imaging using Ultrasonography, ADF (Advanced Dynamic Flow), and fine-needle-aspiration cytology (FNAC) are discussed, comprising a very small micro-focus of radial shape, with markedly hypoechoic echostructure, irregular margins, supplemented by peripheral vessel formation. It acquires an image which appears similar to a brisk visualization of a dark ink stain in the normal thyroid weave. We call such a pattern "Black Ink" with ultrasonographic image and believe consistent with the infiltrating variant of papillary thyroid microcarcinoma if associated with malignant cytology after FNA.

Shorter distance between the nodule and capsule has greater risk of cervical lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

The purpose of this study was to assess the relationship between different sonographic features of papillary thyroid carcinoma (PTC) on high-frequency ultrasound and cervical lymph node metastasis (CLNM).

MATERIALS AND METHODS

We enrolled 548 patients who underwent initial surgery for PTC between May 2011 and December 2012 in our hospital at diagnosis. The sonographic features of 513 PTC nodules in 513 eligible patients, who had single PTC nodules in their thyroid glands, were retrospectively investigated. All patients with a suspect malignant nodule (d<0.5cm) among multiple nodules were initially diagnosed by fine-needle aspiration biopsy (FNAB) to ascertain if the suspect nodule was PTC. The final diagnosis of all the thyroid nodules and existence of CLNM were based on postoperative pathology. Patients were divided into two groups: a positive group with CLNM (224 nodules) and a negative group without CLNM (289 nodules). The following factors were investigated: gender, age, echogenicity, echotexture, size, shape, location, margin, contour, calcification morphology, distance between the nodule and pre- or post-border of the thyroid capsule, vascularity and the differences between the two groups.

RESULTS

Correlation analysis showed that shorter distances between the nodule and pre- or post- border of thyroid capsule resulted in greater risk of CLNM (Spearman correlation coefficient=-0.22, p<0.0001). The significant factors in multivariate analysis were age<45yrs, larger size (d>1cm), "wider than tall" shape, extrathyroid extension and mixed flow (internal and peripheral) (p<0.05, OR=0.406, 2.093, 0.461, 1.610, 1.322).

CONCLUSIONS

Significant sonographic features of PTC nodules in preoperative high-frequency ultrasound are crucial for predicting CLNM.

Prognosis and growth activity depend on patient age in clinical and subclinical papillary thyroid carcinoma

In this review, we focused on the patient age as an indicator of tumor growth and prognostic significance in both clinical papillary thyroid carcinoma (PTC) and subclinical papillary microcarcinoma (PMC: PTC ≤ 1 cm). In clinical PTC, young age (< 30 years) and old age (≥ 60 years) significantly affected the disease-free survival of patients, and old age was a strong predictor of carcinoma death. In contrast, in subclinical PMC, growth activity significantly decreased with patient age, and young age (< 40 years) was an independent predictor of carcinoma growth, indicating that old patients with subclinical PMC are the best candidates for observation without immediate surgery. Taken together, our findings indicate that the role of patients' age as an indicator of tumor growth differs significantly between clinical PTC and subclinical PMC.

Prognostic implications of lymph node yield and lymph node ratio in papillary thyroid carcinoma

BACKGROUND

The lymph node yield (LNY) and the lymph node ratio (LNR) have been shown to be important prognostic factors in oral, colon, and gastric cancers. The role of the LNY and LNR in papillary thyroid cancer (PTC) is unclear. The aims of this study were to determine if a high LNR and a low LNY decrease disease-free survival rates. This study further aimed to determine an optimum nodal yield.

METHODS

A retrospective analysis was conducted of 198 patients with PTC undergoing total thyroidectomy with neck dissection between 1987 and 2011. The LNY and LNR were adjusted by relevant covariates in a multivariate Cox regression analysis with Andersen-Gill extension.

RESULTS

The LNR was associated with a decrease in disease-free survival (hazard ratio 3.2 [95% confidence interval 1.4-7.3], p=0.005). Patients with an LNR of 0.30 or higher had a 3.4 times higher risk of persistent or recurrent disease compared with patients with an LNR of 0.00 ([95% confidence interval 1.1-10.5], p=0.031). Conversely, patients with an LNR of 0.11 or lower had an 80% chance of remaining disease free during 5 years of follow-up. The LNY showed no significant independent effect and an optimum nodal yield was not determined.

CONCLUSIONS

The LNR is an important independent prognostic factor in PTC and can be used in conjunction with existing staging systems. A clinical relevant cut-off point of 0.3 (one positive lymph node out of three total) is proposed. No prognostic implications for LNY were identified.

Predictive factors for lateral occult lymph node metastasis in papillary thyroid carcinoma

Management of lateral no necks in papillary thyroid carcinoma (PTC) is very controversial. The aim of this study was to find predictive factors of lateral neck involvement in N0 PTC to help the clinician in his decision to treat the lateral compartment. We retrospectively analysed 173 patients who underwent thyroidectomy and lateral prophylactic neck dissection for PTC >10 mm. Predictive factors for occult lateral lymph node metastasis including sex, age, tumour size, multifocality and bilaterality, tumour extracapsular spread, vascular invasion and presence of a tumour capsule were examined by multivariate analysis. There were three independent predictive factors for occult lateral lymph node metastases in multivariate analysis: tumour extracapsular spread (p < 0.0001), vascular invasion (p < 0.001) and age <45 years (p < 0.027). When none of these factors was present, the risk of occult metastases was <5 %. The risk increased up to 56 % when at least two of these factors were present. These findings suggest that, in patients older than 45 years with neither tumour extracapsular spread nor vascular invasion on histopathological examination, occult lymph node metastases are very uncommon. In that case further discussion regarding the risks and benefits of lateral nodal dissection may be warranted.

Prognostic factors of papillary and follicular carcinomas in Japan based on data of kuma hospital

There are some important prognostic factors for papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). In this paper, clinicopathological features significantly affecting patient prognosis are described based on our data as well as others. Distant metastasis at diagnosis is the most important prognostic factor for both PTC and FTC. Other than that, preoperative and intraoperative findings are important to evaluate the biological behavior of PTC. Extrathyroid extension, large lymph-node metastasis, and extranodal tumor extension that can be evaluated preoperatively or intraoperatively are significant prognostic factors for PTC patients. In contrast, pathological findings are important not only for diagnosis of FTC, but also for the evaluation of its biological character. Grade of invasiveness (minimally or widely invasive) and degree of differentiation (well differentiated or including a poorly differentiated component) greatly affect the prognosis of FTC patients.

Surgical management of cervical lymph nodes in differentiated thyroid cancer

Well-differentiated thyroid cancer (DTC) carries an excellent prognosis. Although long-term survival rates are high, regional lymph node metastases are common. Surgical management of cervical lymph nodes is integral to the comprehensive treatment of DTC, but data from large randomized trials do not exist to define optimal treatment. Therapy is thus guided by observational data, and founded on an understanding of the behavior of lymphatic metastases in DTC. This article focuses on the significance of lymph node metastases in thyroid cancer, and the strategy for surgical management.

Diagnosis and treatment of a neck node swelling suspicious for a malignancy: an algorithmic approach

Aim. To present an up-to-date algorithm incorporating recent advances regarding its diagnosis and treatment. Method. A Medline/Pubmed search was performed to identify relevant studies published in English from 1990 until 2008. Only clinical studies were identified and were used as basis for the diagnostic algorithm. Results. The eligible literature provided only observational evidence. The vast majority of neck nodes from occult primaries (>90%) represent SCC with a high incidence among middle aged man. Smoking and alcohol abuse are important risk factors. Asiatic and North African patients with neck node metastases are at risk of harbouring an occult nasopharyngeal carcinoma. The remainder are adenocarcinoma, undifferentiated carcinoma, melanoma, thyroid carcinoma and Merkel cell carcinoma. Fine needle aspiration cytology (FNAC) reaches sensitivity and specificity percentages of 81% and 100%, respectively and plays an important role as the second diagnostic step after routine ENT mirror and/or endoscopic examination. FDG-PET/CT has proven to be helpful in identifying occult primary carcinomas of the head and neck, especially when applied as a guiding tool prior to panendoscopy, and may induce treatment related clinical decisions in up to 60% of cases. Conclusion. Although reports on the diagnostic process offer mainly descriptive studies, current information seems sufficient to formulate a diagnostic algorithm to contribute to a more systematic diagnostic approach preventing unnecessary steps.

99Tc Nanocolloid sentinel node procedure in thyroid carcinoma

PURPOSE

The purposes of this study were to investigate the efficacy of radiocolloid lymphoscintigraphy and of handheld gamma probe procedure for sentinel lymph node biopsy (SLNB) in papillary thyroid carcinoma (PTC) and to evaluate its results in clinical staging.

MATERIALS AND METHODS

Sixty-five PTC consecutive patients entered the study. Patients underwent radiocolloid lymphoscintigraphy before surgery. Intraoperative sentinel lymph node (SLN) localization was performed using a handheld gamma probe. They were followed up at 2, 6 months, and yearly.

RESULTS

SLN metastases were diagnosed in 52%. Fifty-one patients underwent ablative 131-I therapy. The mean Tireoglobulin level in N0 vs N1 cases was 2.2 ng/ml vs 4.73 (p = 0.03) and 0.68 vs 2.1 ng/ml (p = 0.005) before and after 131-I therapy, respectively.

CONCLUSIONS

In patients classified N0 by SLNB, ablative 131-I therapy could be avoided.

Diagnostic utility of thyroglobulin detection in fine-needle aspiration of cervical cystic metastatic lymph nodes from papillary thyroid cancer with negative cytology

Cystic changes in metastatic cervical lymph nodes (CLN) from papillary thyroid cancer (PTC) may be a diagnostic pitfall in fine-needle aspiration biopsy (FNAB) cytology. We investigated in a series of CLN metastases from thyroid cancers (TC), including cystic PTC, and from a wide spectrum of extrathyroidal malignancies, the diagnostic role for metastatic TC of the rapid detection of thyroglobulin in eluates from FNAB (FNAB-Tg) of CLN. The study was carried out in a group of 79 subjects (22/57 M/F; median age, 56 years; range, 20-86 years) with enlarged CLN and thyroid nodules (TN), examined for potential metastatic TC, and harboring a large spectrum of incidentally diagnosed extrathyroidal malignancies (n = 24, mostly represented by lymphomas, lung, and breast cancers), CLN metastases from thyroid cancers (n = 28, including 6 cystic metastatic PTC), 6 specific lymphadenitis and 21 reactive lymphadenitis mostly detected (n = 16) during follow-up of patients with previously ablated TC. Markedly high FNAB thyroglobulin (Tg) values were found in all metastatic CLN TC. Two of the six cases with cystic metastatic CLN PTC were diagnosed by FNAB-Tg but not by cytology. In conclusion, FNAB-Tg has been confirmed as an easy modality and fast procedure to diagnose CLN metastasis from TC and high FNAB-Tg values with nondiagnostic cystic cytology strongly suggest cystic metastatic PTC.

Incidental metastatic papillary thyroid carcinoma in microvascular reconstruction

OBJECTIVES/HYPOTHESIS

Occult papillary thyroid carcinoma has a reported prevalence of 1% to 35% based on autopsy studies. Cervical lymphatic metastases from papillary thyroid carcinoma have been associated with a higher likelihood of recurrence with a questionable impact on survival. Without clinically evident disease in the thyroid or cervical nodes, management of these patients presents a treatment dilemma. We propose an individualized treatment plan for patients in whom metastatic papillary thyroid carcinoma is incidentally detected during neck exploration for other purposes.

STUDY DESIGN

Retrospective review and discussion of the literature.

METHODS

The clinical course of two patients with incidentally discovered metastatic papillary thyroid carcinoma to the cervical lymph nodes is described. Both patients had previously received head and neck irradiation in childhood and required free flap reconstruction of extensive skull base defects following extirpation of meningiomas.

RESULTS

Neck dissection specimens from levels I and II obtained during exposure of recipient vessels for microvascular tissue transfer revealed papillary thyroid carcinoma in both cases. The patients subsequently underwent total thyroidectomy, neck dissection, and postoperative radioactive iodine ablation of residual thyroid tissue. After 1 year of follow-up, both patients were without evidence of recurrent disease.

CONCLUSIONS

An individualized approach is justified to treat metastatic papillary thyroid carcinoma incidentally discovered during other procedures. The case reports underscore the importance of pathological analysis of surgical specimens obtained during head and neck reconstruction.

Sentinel lymph node biopsy in staging of differentiated thyroid cancer: a critical review

Sentinel lymph node biopsy has recently been utilized to map tumor lymphatics in patients with differentiated thyroid carcinoma. Currently, controversy centers around the feasibility and future role of this technique in the management of differentiated thyroid cancer patients. A review of the current literature in which sentinel lymph node biopsy was performed on patients with a diagnosis of differentiated thyroid cancer was undertaken. Sentinel lymph node biopsy has been carried out on thyroid cancer patients utilizing a vital dye technique, a radiotracer technique, and a combination of both techniques. In the current literature the average rate of sentinel node identification is 91% (range 66-100%) and when identified, the sentinel node accurately predicts the disease status of the neck in most patients (range 80-100%). Limitations to carrying out the sentinel node biopsy on thyroid cancer patients include staining of parathyroid glands, identification of lymph nodes draining into the mediastinum, and the 'shine through' effect. Sentinel lymph node biopsy is technically feasible, but for a disease in which nodal metastases are of debatable prognostic value, the clinical utility of sentinel lymph node biopsy in the management of patients with differentiated thyroid cancer appears less than promising.

Predictive factors for node involvement in papillary thyroid carcinoma. Univariate and multivariate analyses

For patients with papillary thyroid carcinoma, lymph node involvement is a common complication, resulting in node dissection and its resulting morbidity. To determine means of limiting lymph node dissections, we attempted to define intra-operative criteria predictive of node metastasis and so identify the patients likely to benefit from this procedure. This retrospective study concerned 158 patients (118 female) treated between 1974 and 1996 for papillary thyroid carcinoma by total thyroidectomy associated with bilateral (central and lateral) (n = 119) or unilateral (n = 39) dissection. The following criteria were used to study the predictive value of node involvement: age, sex, tumour size, tumour site, uni- or multifocality, existence or not of a tumour capsule, existence or not of perithyroid involvement and presence or not of vascular invasion. 99 patients (63%) had node involvement. Four factors showed predictive value for node involvement in univariate analysis: vascular invasion (P = 0.02), male sex (P = 0.008), absence of a tumour capsule (P < 0.0001) and perithyroid involvement (P < 0.0001). Two factors were predictive in multivariate analysis: absence of a tumour capsule and perithyroid involvement. Our results enabled us to calculate the risk of node involvement for each patient as a function of the existence of a peritumoral capsule and/or perithyroid involvement and to determine the indication for dissection. When neither of these factors was present, the risk of node involvement was 38.3% and dissection was not considered essential. If both risk factors were found, the risk was 87.1% and dissection was considered necessary.

Pattern of lymph node metastases in papillary thyroid carcinoma

BACKGROUND

Incidence and pattern of lymph node metastasis (LNM) were evaluated in 35 patients who underwent primary surgery for papillary thyroid carcinoma.

METHODS

Total thyroidectomy with systematic cervicocentral lymphadenectomy was performed routinely. Additionally, 22 patients underwent lymphadenectomy of the ipsilateral cervicolateral compartment. Sternotomy was performed in four patients.

RESULTS

Primary tumour status was: pT1, n = 7; pT2, n = 12; pT3, n = 4; pT4, n = 12. Twenty-four patients had LNM in the ipsilateral cervicocentral compartment (pT1, n = 2; pT2, n = 8; pT3, n = 4; pT4, n = 10). Nineteen had LNM in the ipsilateral cervicolateral compartment (pT1, n = 4; pT2, n = 6; pT3, n = 2; pT4, n = 7). Contralateral cervicocentral LNM was restricted to patients with pT3 tumours (n = 2) or pT4 tumours (n = 3). No patient had LNM in the contralateral cervicolateral compartment. Only one patient (pT3 tumour) had mediastinal LNM.

CONCLUSION

The cervicocentral compartment was most commonly involved with metastases, although the ipsilateral cervicolateral compartment was almost as often affected. In some patients ipsilateral cervicolateral LNM was present in the absence of cervicocentral LNM. Contralateral cervicolateral and upper mediastinal LNM, however, were rare. This study helps to plan radical surgery for papillary thyroid carcinoma.