Diffuse sclerosing variant of papillary thyroid carcinoma. A clinicopathologic study of 10 cases

Relationship between recurrence and age in the diffuse sclerosing variant of papillary thyroid carcinoma: clinical significance in pediatric patients

Background

The diffuse sclerosing variant (DSV) is among the aggressive variants of papillary thyroid carcinoma (PTC) and is more prevalent in pediatric patients than in adult patients. Few studies have assessed its characteristics owing to its low incidence. We aimed to evaluate the relationship between recurrence and age in the DSV of PTC.

Methods

We retrospectively reviewed patients diagnosed with the DSV or conventional PTC (cPTC) after surgery at a medical center between May 1988 and January 2019. We compared the clinico-pathological characteristics and surgical outcomes of the DSV and cPTC groups and between adult and pediatric patients with DSV.

Results

Among the 24,626 patients, 202 had the DSV, and 24,424 were diagnosed with cPTC. The recurrence rate was significantly higher in the DSV group than in the cPTC group. In the DSV group, the recurrence rate was significantly higher in the pediatric patient group than in the adult patient group. Moreover, the association between recurrence and age group showed different patterns between the DSV and cPTC groups with restricted cubic splines (RCS). While both RCS curves showed a U-shaped distribution, the RCS curve tended to be located within the younger age group.

Conclusions

This study demonstrated that pediatric patients with DSV are at a greater risk for recurrence compared with adult patients; moreover, the pattern of recurrence risk according to age is different from that of cPTC.

The Current Histologic Classification of Thyroid Cancer

Thyroid cancers of follicular cell derivation provide excellent phenotype-genotype correlations. Current morphologic classifications are complex and require simplification. Benign adenomas have follicular or papillary architecture and bland cytology. Well-differentiated thyroid carcinomas exhibit follicular architecture, expansile growth, and variable cytologic atypia and invasiveness; low-risk tumors have excellent prognosis after surgical resection whereas widely-invasive and angioinvasive tumors warrant total thyroidectomy and radioablation. Papillary carcinoma is less differentiated; indolent microcarcinomas can be managed by active surveillance, whereas clinical lesions with local or distant spread require therapy. Progression gives rise to poorly differentiated and anaplastic carcinomas that are less common but far more aggressive.

Special types of thyroid carcinoma

This article reviews the small percentage of thyroid tumours that are not classified as classic papillary thyroid carcinoma, follicular thyroid carcinoma, and medullary thyroid carcinoma. It includes subtypes of papillary thyroid carcinoma, including, tall-cell, hobnail/micropapillary, columnar cell, diffuse sclerosing and solid variants. Poorly differentiated carcinoma, high-grade carcinoma and anaplastic thyroid carcinoma are reviewed. Also discussed are entities that are unusual but need to be recognized as primary thyroid neoplasms, i.e. mucoepidermoid carcinoma, sclerosing mucoepidermoid carcinoma with eosinophilia, and mammary analogue secretory carcinoma/secretory carcinoma. The pathological features and prognostic factors are described; a brief review of molecular correlates of these neoplasms is included.

Prognostic significance of diffuse sclerosing variant papillary thyroid carcinoma: a systematic review and meta-analysis

OBJECTIVE

Diffuse sclerosing variant papillary thyroid carcinoma (DSVPTC) is an uncommon variant of papillary thyroid carcinoma (PTC). The biological behaviors and prognostic outcomes of this variant, however, are still controversial. The aim of this systematic review and meta-analysis is to investigate the prognostic significance and outcomes of DSVPTCs in comparison with classical PTCs (cPTCs).

METHODS

An electronic search was performed in five libraries: PubMed, Scopus, ISI, World Health Organization Global Health Library (WHO GHL) and Virtual Health Library (VHL) in June 2016. Published data were extracted and were pooled into odds ratios (OR), mean differences and corresponding 95% confidence intervals (CI) using random-effect model. Publication bias was analyzed using Egger's regression test and funnel plot observation.

RESULTS

From 315 articles, we included 16 articles comprising 732 DSVPTCs for meta-analysis. Overall, DSVPTC manifested more aggressive clinicopathological behaviors than cPTC such as higher rate of vascular invasion (OR: 5.33; 95% CI: 3.08-9.23), extrathyroidal extension (OR: 2.96; 95% CI: 2.04-4.30), lymph node metastasis (OR: 5.40; 95% CI: 2.82-10.35), distant metastasis (OR: 3.61; 95% CI: 1.89-6.88) and were more likely to relapse (OR: 2.83; 95% CI: 1.59-5.05). DSVPTC patients were associated with a worsened overall survival (HR: 1.89; 95% CI: 1.36-2.62).

CONCLUSION

DSVPTCs should be considered high-risk PTCs because of high propensity for tumor invasion, metastasis, relapse and mortality. Aggressiveness of DSVPTCs might be related to a different molecular pathway than that in cPTCs.

Ultrasonographic imaging of papillary thyroid carcinoma variants

Ultrasonography (US) is routinely used to evaluate thyroid nodules. The US features of papillary thyroid carcinoma (PTC), the most common thyroid malignancy, include hypoechogenicity, spiculated/microlobulated margins, microcalcifications, and a nonparallel orientation. However, many PTC variants have been identified, some of which differ from the classic type of PTC in terms of biological behavior and clinical outcomes. This review describes the US features and clinical implications of the variants of PTC. With the introduction of active surveillance replacing immediate biopsy or surgical treatment of indolent, small PTCs, an understanding of the US characteristics of PTC variants will facilitate the individualized management of patients with PTC.

Outcome of the Diffuse Sclerosing Variant of Papillary Thyroid Cancer: A Meta-Analysis

INTRODUCTION

The diffuse sclerosing variant (DSV) of papillary thyroid cancer (PTC) is considered an aggressive histotype associated with poor prognosis. However, the available data for both the outcome and best management of this disease are inconsistent.

METHODS

This study reviewed the current literature by searching PubMed up to November 30, 2015, using the search terms "diffuse sclerosing variant" and "papillary thyroid cancer (or carcinoma)" and selecting only studies evaluating recurrent/persistent disease and cancer-related mortality in both DSV and classic PTC (cPTC). The association with some features of aggressiveness at diagnosis, the risk of recurrence or persistence, and the risk of cancer-related death were reported as odds ratio (OR) with confidence intervals (CI). Meta-regression analysis was used to assess the effect of covariates across the studies.

RESULTS

Ten studies met the eligibility criteria and contributed 585 DSV and 64,611 cPTC patients. Relative to patients with cPTC, patients with DSV exhibited a higher risk of extrathyroidal extension and lymph node and distant metastases. The risk of persistent/recurrent disease was three times higher in patients with DSV than it was in cPTC patients (OR = 3.19 [CI 1.86-5.49]). This risk was not different when only studies where post-surgical (131)I was routinely administered were considered (OR = 2.07 [CI 0.88-4.90]). The risk of cancer-related mortality was not different between DSV and cPTC (OR = 1.34 [CI 0.76-2.38]).

CONCLUSIONS

This meta-analysis confirms the aggressive biological behavior of DSV thyroid cancer. When preoperatively suspected, total thyroidectomy with lymph node excision followed by radioiodine therapy should be the correct management for DSV.

Mammary Analog Secretory Carcinoma (MASC) Involving the Thyroid Gland: A Report of the First 3 Cases

Salivary gland-type tumors have been rarely described in the thyroid gland. Mammary Analog Secretory Carcinoma (MASC) is a recently defined type of salivary gland carcinoma characterized by a t(12;15)(p13;q25) resulting in an ETV6-NTRK3 fusion gene. We report 3 cases of MASC involving the thyroid gland without clinical evidence of a salivary gland or breast primary; the clinico-pathologic characteristics are reviewed. Assessment for rearrangement of the ETV6 (12p13) locus was conducted by fluorescence in situ hybridization (FISH) on representative FFPE sections using an ETV6 break apart probe (Abbott Molecular, Des Plaines, IL, USA). The patients were two females (52 and 55 years-old) and 1 male (74 years-old). The tumors were poorly circumscribed solid white tan nodules involving the thyroid. Histologically, they were invasive and showed solid, microcystic, cribriform, and tubular growth patterns composed of variably bland polygonal eosinophilic cells with vesicular nuclear chromatin and conspicuous nucleoli. All three cases showed metastasis to lymph nodes; one case showed lateral neck involvement. The tumor cells were positive for S100 and mammaglobin. GATA-3 and PAX-8 were positive in 2 cases, one of which only focally so. All three cases were negative for TTF-1 and thyroglobulin. Rearrangement of the ETV6 locus was confirmed in all cases and a diagnosis of MASC rendered for each case. A site of origin distinct from the thyroid gland was not identified, with a median follow up of 24 months. MASC may rarely involve the thyroid gland. The origin of these lesions is unknown; while an origin from ectopic salivary gland-type cells is entertained, a metastatic origin from an occult primary cannot be definitively excluded at this time. Given the histologic (follicular-like microcystic pattern with colloid-like secretions and papillary pattern), immunophenotypic (PAX-8), and even molecular overlap, MASC can be mistaken for papillary thyroid carcinoma and should be considered in the differential diagnosis of a thyroid mass.

Sonographic and cytopathologic correlation of papillary thyroid carcinoma variants

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and constitutes more than 70% of thyroid malignancies. Although TNM staging is the most widely used parameter for determination of therapeutic plans, recent studies have suggested that different histopathologic variants of PTC can also have different clinical courses and patient prognoses. Sonographic criteria for PTC are well established and include a taller-than-wide shape, an irregular margin, microcalcifications, and marked hypoechogenicity. The role of sonography has expanded to enable the characterization of PTC variants based on their sonographic features. Tall cell and diffuse sclerosing variants appear to have more aggressive clinical courses with unfavorable prognoses, whereas the more recently described cribriform-morular and Warthin-like variants have relatively indolent clinical courses. The prognoses of patients with follicular, solid, columnar cell, and oncocytic variants are still controversial and may be similar to the prognosis of conventional PTC. Understanding the sonographic characteristics of PTC variants with clinicopathologic correlation may be helpful for suggesting an appropriate treatment plan.

Lymph node metastases do not impact survival in follicular variant papillary thyroid cancer

INTRODUCTION

Follicular variant of papillary thyroid cancer (FVPTC) is the most common and fastest growing subtype of papillary thyroid cancer (PTC) with features of both PTC and follicular thyroid cancer (FTC). The purpose of this study was to determine the patient and tumor features associated with lymph node metastases (LNM) in FVPTC.

METHODS

This was a retrospective review of adult (≥18) patients with histologically confirmed diagnoses of FVPTC within the SEER database between 1988 and 2009. LNM were defined by at least two lymph nodes with metastatic disease. To determine factors associated with LNM, we constructed a multivariate logistic regression model from significant variables (p < 0.05) identified on univariate analysis. Similarly, we used a Cox proportional hazards model to understand the relative importance of LNM in determining disease-specific mortality (DSM).

RESULTS

Of the 20,357 cases of FVPTC with lymph node data available, 1,761 (8.7%) had LNM; 61.1% of these LNM were located in the central neck and 38.9% were in the lateral neck. Extrathyroidal extension (odds ratio [OR] 2.6, 95% confidence interval [CI] 2.2-3.0, p < 0.01) and multifocality (OR 3.0, 95% CI 2.5-3.6, p < 0.01) were the strongest predictors of LNM. Importantly, LNM did not independently predict DSM (p = 0.52). Tumor size >4 cm (hazards ratio [HR] 5.3, 95% CI 2.2-12.8, p < 0.01) and extrathyroidal extension (HR 8.2, 95% CI 3.0-22.0, p < 0.01) were the strongest predictors of DSM.

CONCLUSIONS

LNM occur in less than 10% of patients with FVPTC but do not impact DSM. Instead, DSM in FVPTC is related to size and local invasion.

Aggressive variants of follicular cell-derived thyroid carcinomas: a cytopathologist's perspective

Follicular cell-derived carcinomas of the thyroid gland comprise a heterogeneous group of malignant neoplasms of the thyroid gland with varied histologic appearance and molecular profiles. In most patients, these tumors represent relatively indolent neoplasms; however, certain subtypes/variants behave in an aggressive manner, and the recognition of this subset of tumors is essential because of their variable response to therapy and significant morbidity and mortality. Fine-needle aspiration is considered an essential tool for the diagnosis of suspicious thyroid nodules. In this review, the authors discuss the clinical, histologic, and molecular findings and the prognostic implications of aggressive thyroid neoplasms with emphasis on the characteristic cytomorphologic features on fine-needle aspiration smears.

Pathologic diagnosis of papillary thyroid carcinoma: today and tomorrow

Papillary thyroid carcinoma is the most common malignancy of the thyroid. It is a well-differentiated tumor and the majority behaves in an indolent fashion. The pathologic diagnosis of papillary carcinoma in both cytology and histologic specimens is based upon demonstration of typical nuclear morphology. Using these morphologic criteria, most papillary cancers can be diagnosed with ease, except cases in which there is a paucity of diagnostic nuclear features. Despite advances in the treatment of thyroid cancer, disease recurrences and metastasis can be observed in 20% of cases. Recently, many advances have been made in the pathogenesis of papillary thyroid carcinoma. The notable genetic events include Ret/PTC rearrangements, Ras and BRAF gene mutations. The identification of these has also led to their use in diagnosis and predicting prognosis of papillary thyroid carcinoma. In addition, these involved genes may also serve as targets for cancer chemotherapy in patients where standard thyroid cancer treatment is not effective.

Aggressive variants of papillary thyroid microcarcinoma are associated with extrathyroidal spread and lymph-node metastases: a population-level analysis

BACKGROUND

Tall cell variant (TCV) and diffuse sclerosing variant (DSV) of papillary thyroid cancer are aggressive subtypes, for which tumors ≤1 cm have not been exclusively studied.

METHODS

The SEER database (1988-2009) was used to compare characteristics of TCV ≤1 cm (mTCV) and DSV ≤1 cm (mDSV) with classic papillary thyroid microcarcinoma (mPTC). Survival was analyzed with the Kaplan-Meier method and log-rank test, and risk factors for nodal metastases with chi-square analysis and binary logistic regression.

RESULTS

There were 97 mTCV, 90 mDSV, and 18,260 mPTC patients. mTCV incidence increased by 79.9% (p=0.153) over the study period, while mDSV incidence decreased by 10.3% (p=0.315). Compared to classic mPTC, mTCV tended to be larger on average (7.1 mm vs. 5.3 mm, p<0.001), with higher rates of multifocality (47.2% vs. 34.0% respectively, p=0.018) and lymph-node examination (63.9% vs. 39.2% respectively, p<0.001), while in mDSV, nodal metastases were more frequent (57.1% vs. 33.1% respectively, p=0.007). Both aggressive variants had higher rates of extrathyroidal extension (27.8% mTCV vs. 13.3% mDSV vs. 6.1% mPTC, p<0.001). Aggressive variants also received radioactive iodine more frequently (39.2% mTCV vs. 40.0% mDSV vs. 29.1% mPTC, p<0.001). However, they were not statistically more likely to receive thyroidectomy over lobectomy compared to classic mPTC. There were no significant differences in overall and disease-specific survival between the histologies. In mTCV, after adjustment, extrathyroidal extension was independently associated with size >7 mm (odds ratio (OR) 4.4 [CI 1.5-13.6]) and nodal metastasis with multifocality (OR 5.4 [CI 1.3-23.4]) and extrathyroidal extension (OR 5.8 [CI 1.3-25.4]). No statistically significant predictors of extrathyroidal extension or nodal metastasis in mDSV were observed.

CONCLUSIONS

Aggressive variants of mPTC tend to exhibit more aggressive pathologic characteristics than classic mPTC, but survival appears to be similar. Treatment with total thyroidectomy and central lymphadenectomy may be warranted if the diagnosis can be made pre- or intraoperatively.

Aggressive variants of follicular cell derived thyroid carcinoma; the so called 'real thyroid carcinomas'

The pathological diagnoses and classification schemes for thyroid carcinoma have changed over the past 20 years and continue to do so. New entities have been described and molecular analyses have suggested better characterisation and grouping of certain tumours. Because some of the lesions have been named differently by different authors, clinicians and patients may be confused as to what a specific patient's lesion represents. In this review, we discuss the thyroid tumours of follicular origin which are clinically unusual but important to recognise as their behaviour may be aggressive, they may not respond to radioiodine treatment and they may cause significant mortality. This paper describes these important but rare lesions, their pathological features, important clinicopathological correlations, molecular correlates and prognostic implications.

Estrogen receptor- and progesterone receptor-positive diffuse sclerosing variant of papillary thyroid carcinoma: a case report

The diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is a relatively rare tumor. We herein report the case of young woman with DSV-PTC who developed cervical lymph node recurrence 7 years after the initial surgery. A 15-year-old female patient with no medical or family history of thyroid tumors developed a thyroid neoplasm in the right lobe. Right thyroidectomy and regional lymphadenectomy were performed, and the tumor was diagnosed as DSV-PTC. She was followed up as an outpatient. Seven years after the surgery, cervical lymph node recurrence developed. On microscopic examination, the thyroid tumor showed a papillary growth pattern with numerous psammoma bodies and distinct fibrosis. Immunohistochemically, the tumor cells were estrogen receptor and progesterone receptor positive with reduced membranous expression of E-cadherin and were intermingled with S-100-positive dendritic/Langerhans cells. DSV-PTC is characterized by a strong tendency for invasion and metastasis. Thus, accurate diagnosis is clinically important, and a morphological and immunohistochemical understanding of DSV-PTC is necessary.

Papillary thyroid carcinoma: an update

The past two decades have seen numerous developments in the understanding of the origins and biology of papillary thyroid carcinoma. Advances in molecular biology, clinicopathologic studies of new entities, facility with fine-needle aspiration biopsy, and new radiologic imaging techniques have allowed for earlier diagnosis of these tumors. However, these advances have also caused controversies in cytologic and histopathologic diagnoses as well as therapy decisions. This paper will focus on several pathologic aspects of papillary carcinoma, which impact on its biology and prognosis.

A diffuse sclerosing variant of papillary thyroid carcinoma: clinical and pathologic features and outcomes of 34 consecutive cases

BACKGROUND

The diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is a relatively rare variant of papillary thyroid cancer. Large studies of patients with DSPC have been infrequently performed, and controversy still exists concerning some DSPC features and outcomes. The aim of the present study was to retrospectively evaluate the clinicopathologic features and outcomes in a series of 34 consecutive patients with DSPC and to compare them with a larger group of 245 consecutive patients with the classic variant of papillary thyroid carcinoma (cPTC) that were evaluated in the same period.

PATIENTS AND METHODS

Clinical and histological features (sex, age, tumor size,multifocality, bilaterality, extra thyroid extension, and local and distant metastases) were recorded in all patients, as well as any persistent or recurrent disease and the patients' disease status at last observation. Patients with cPTC were classified as either low (122) or high risk (123). DSPC and high-risk patients were all treated with the same protocol, including ¹³¹I treatment. All patients were included in a Cox regression model analysis to investigate the effect of each variable on the hazard ratio.

RESULTS

As expected, multifocality, bilaterality, and extra thyroid extension were more frequently noted at presentation, and the pT1 category of TNM classification was less frequently noted in DSPC and high-risk patients with cPTC compared with low-risk patients with cPTC. No significant difference was found between patients with DSPC and those with high-risk cPTC, except that extra thyroid extension was found more frequently in the patients with DSPC. Using multivariate analysis, diffuse sclerosing variant was an independent variable for predicting a high risk of persistent and recurrent disease during initial follow-up. However, at a later time, and after further treatment, the disease status was not different between patients with DSPC and those with high-risk cPTC, and only the presence of distant metastases affected the final outcome.

CONCLUSIONS

DSPC is a thyroid papillary carcinoma variant characterized by high aggressiveness. In patients with DSPC, the outcome is worse than in patients with low-risk cPTC; and, at presentation, characteristics are somewhat worse than for patients with high-risk cPTC.At medium term, the outcome is similar to that observed in patients with high-risk cPTC, provided aggressive treatment is used (additional surgical intervention, when required, and/or ¹³¹I radiotherapy).

Diffuse sclerosing variant is a major subtype of papillary thyroid carcinoma in the young

BACKGROUND

Pediatric thyroid cancer differs from adult thyroid cancer in presentation and outcome. Pediatric thyroid cancer has a higher recurrence rate and greater percentage of lymph node and pulmonary metastasis. The clinicopathologic characteristics of pediatric thyroid cancer according to the histologic subtype have not been reported, however. In this study, we determined the histological subtypes of pediatric thyroid cancer and analyzed other clinicopathologic characteristics.

METHODS

All patients with thyroid cancer who were admitted to Severance Hospital, Seoul, South Korea, were retrospectively reviewed; their age was <20 years at diagnosis, and they were seen between January 1995 and August 2008.

RESULTS

Sixty-eight patients were identified. The histologic types of thyroid carcinoma were papillary thyroid carcinoma (PTC) in 57 (83.8%), follicular carcinoma in 8 (11.8%), and poorly differentiated carcinoma in 3 (4.4%). There were 28 (41.2%) cases of diffuse sclerosing variant of papillary carcinoma (DSVPC), 26 (38.2%) of conventional PTC, 2 (2.9%) of follicular PTC, and 1 (1.5%) cribriform-morular PTC. In patients with PTC, there was a higher incidence of bilateral thyroid involvement (p = 0.003), extrathyroidal extension (p = 0.009), and lymph node involvement (p = 0.018), and lower recurrence-free survival (p = 0.032) in DSVPC than in non-DSVPC. Univariate regression analysis revealed that extrathyroidal extension (p = 0.025) and tumor size (p = 0.001) were positively associated with a shorter time to recurrence.

CONCLUSION

DSVPC is a major subtype of PTC in the young.

BRAFV600E mutation in papillary thyroid carcinoma: a potential target for therapy?

This article reviews the therapeutic significance of the close genotype-phenotype association in papillary thyroid carcinoma, namely regarding the association between genetic alterations in RET, BRAF or RAS genes and the histopathological variants of papillary thyroid carcinoma. Based upon the aforementioned review on morphology and molecular pathology, the most recent prognostic and therapeutic data are reviewed and the role of targeted therapies, namely those interfering with BRAF-activated pathways are discussed, which may play a role in the treatment of patients with papillary thyroid carcinoma unresponsive to radioactive iodine.

Diffuse sclerosing variant of papillary carcinoma of the thyroid: imaging and cytologic findings

Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is a rare variant of papillary thyroid carcinoma, for which the imaging and cytologic features have not been reported. The aim of this study is to gain better insight into the characteristic imaging and cytologic features of DSPC and to suggest treatment guidelines. We retrospectively analyzed the ultrasonographic and computed tomographic (CT) features in eight patients diagnosed with pathologically proven DSPC between 1996 and 2006. Of these eight patients, five patients underwent preoperative ultrasonography (US)-guided fine-needle aspiration (FNA). All the patients were women, who presented at a relatively young age (mean age: 31.9 years) with large tumors (mean diameter: 5.9 cm) and cervical lymph node metastases. The US features (7/8) of DSPC were heterogeneous echotexture (7/7), solid composition (7/7), ill-defined margins (4/7), scattered microcalcifications having snowstorm appearance (7/7), and various echogenicities. CT findings (6/8) revealed numerous microcalcifications and multiple enlarged nodes in all the patients. Cytological examination showed lymphocytes intermingled with nests of tumor cells, psammoma bodies, and squamous differentiation with typical nuclear features of papillary carcinoma in all. Through the combination of typical imaging findings and careful cytological examination, DSPC can be diagnosed preoperatively, allowing for the aggressive surgical treatment required in treating this disease.

Unusual findings in papillary thyroid microcarcinoma suggesting partial regression: a study of two cases

Histologic changes of regression have been recognized in many malignant tumors, although they have not been documented in thyroid carcinoma. We analyze here the histologic features of 2 cases of papillary thyroid microcarcinoma, one of the diffuse sclerosing variant and another multicentric of the follicular variant, that suggest partial regression. The histologic and clinical features of the 2 thyroid microcarcinomas were compared with the features of regression reported in other tumors. Hematoxylin and eosin stains were examined in each case. In addition, immunoperoxidase stains for thyroglobulin and thyroid transcription factor-1 were performed on the metastatic and primary lesions of each case. Immunostains for CD4 and CD8 performed on the thyroid lesions were also examined. Both patients presented with metastatic papillary thyroid carcinoma in regional lymph nodes with no clinical or radiologic evidence of primary tumor in the thyroid glands. When examined, the thyroid glands revealed only microscopic foci of papillary thyroid carcinoma measuring less than 1.5 mm, diffuse sclerosis and a lymphocytic infiltrate mainly composed of cytotoxic T lymphocytes around the neoplastic microfollicles. Numerous psammoma bodies were also found in the thyroid of case 1, and venulitis similar to that seen in acute hepatic rejection was also seen in the microcarcinoma of case 2. The 2 patients reported had papillary thyroid microcarcinomas measuring less than 1.5 mm and features suggestive of regression characterized by extensive fibrosis, an accompanying T lymphocyte infiltrate, venulitis, and only a few clusters of neoplastic cells or a few neoplastic follicles. Thus, we believe that these histologic changes suggest regression because papillary thyroid microcarcinomas measuring less than 1.5 mm do not metastasize and have been considered innocuous or medical curiosities.

Diffuse sclerosing variant of papillary carcinoma of the thyroid: ultrasound features with histopathological correlation

AIM

To evaluate the ultrasound (US) features of the diffuse sclerosing variant of papillary carcinoma (DSVPC) of the thyroid, with histopathological correlations.

MATERIALS AND METHODS

The US and histopathological findings of six patients with surgically proven DSVPC of the thyroid were retrospectively assessed.

RESULTS

Most of cases showed diffuse, scattered microcalcifications with or without associated masses and underlying heterogeneous hypoechogenicity at the site of the DSVPC in the thyroid. At ultrasound, scattered microcalcifications and heterogeneous hypoechogenicity seen in the DSVPC correlated to psammoma bodies and lymphocytic infiltration at histopathological review.

CONCLUSION

DSVPC of the thyroid usually manifested as diffuse scattered microcalcifications and associated suspicious mass on ultrasound. These findings are not specific for the DSVPC of the thyroid. However, in relatively young patients with suspicious masses associated with underlying diffuse scattered microcalcifications on US, the possibility of DSVPC should be included in differential diagnosis.

Special Variants of Differentiated Thyroid Cancer: Does It Alter the Extent of Surgery Versus Well-Differentiated Thyroid Cancer?

INTRODUCTION

Recently, more aggressive variants of so-called well-differentiated thyroid carcinomas have been identified such as the tall cell variant, columnar cell variant, diffuse sclerosing variant, insular carcinoma, and Hürthle cell (oncocytic, oxyphilic) carcinomas.

METHODS

An evidence-based review was performed to identify the optimal treatment recommendations for these thyroid cancers of intermediate differentiation.

CONCLUSIONS

Although some variation exists within the group, aggressive surgical and medical management are recommended for these neoplasias. Any such recommendations should, however, be viewed in the light of the fact that the current literature mainly consists of case reports, case series, and limited reviews. The clinical presentation, pathophysiology, diagnosis, and surgical and medical management for these thyroid cancers with intermediate differentiation are discussed.

Prognostic Importance of Sclerosing Variant in Papillary Thyroid Carcinoma

The diffuse sclerosing variant (DSV) of papillary thyroid carcinoma is known for its high aggressiveness, high incidence of lymph node metastases, and high incidence of pulmonary metastases, and thus its consequently poorer prognosis. In this study, we undertook a retrospective analysis of papillary thyroid carcinomas to assess whether DSV can be considered a predictive factor for prognosis. We performed a retrospective evaluation of the Department's database of patients with papillary thyroid carcinoma who had undergone total thyroidectomy from January 1992 to December 2000. Group I consisted of 83 DSV patients and Group II was 168 pure papillary carcinoma (PC) patients. A significant prevalence of multinodular thyroid disorder on diagnosis was found for PC (P < 0.05), whereas with DSV, there was a significantly higher prevalence of post-thyroiditis nodular thyroid disorder than with PC (P < 0.001). The incidence of laterocervical lymph node pathology on diagnosis was significantly higher for DSV (P < 0.05). In 3.6 per cent of PC patients and 15.7 per cent of DSV patients, we observed recurrences in the regional lymph nodes (P < 0.001). We found 1.2 per cent distant metastases in PC patients and 7.2 per cent in DSV patients (P < 0.05). One PC patient (0.6%) and three DSV patients (3.6%) died of tumor-related causes (P < 0.05). Our study demonstrated that diffuse sclerosing carcinoma leads to a poorer prognosis to the extent that its classification as an autonomous clinical pathological entity is justified. In conclusion, we can state that DSV is a form of papillary thyroid tumor characterized by its higher aggressiveness, diffuse intrathyroid growth, and high incidence of lymph node and pulmonary metastasis. Ultimately, this means a poorer prognosis. In the presence of risk factors indicating a possible increase in biological aggressiveness, adequate postoperative treatment and close follow-up become essential.

Diffuse Sclerosing Variant of Papillary Carcinoma of the Thyroid: A 35-Year Comparative Study at a Single Institution

BACKGROUND

Diffuse sclerosing variant (DSV) is a rare variant of papillary thyroid carcinoma (PTC), and the features of this carcinoma have not been fully characterized. The aim of this study was to analyze the clinicopathologic features of a large cohort of patients with this disease.

METHODS

We reclassified primary thyroid carcinomas treated in a 35-year study period and studied the clinicopathologic features and outcomes of DSV of PTC in comparison with classic PTC.

RESULTS

Fifteen patients (2 men and 13 women) with DSV of PTC were identified who had surgical resection of the thyroid. Fine-needle aspiration biopsy diagnosed 83% (10 of 12) of the tumors. Compared with classic PTC, patients with DSV presented at a younger age (mean age, 29 vs. 46 years; P = .0001), had larger tumors (mean diameter, 3.6 vs. 2.2 cm; P = .002), and had a higher incidence of cervical nodal metastases (80% vs. 43%; P = .006). Ten patients had received postoperative iodine 131 ablation, and four had also received external-beam irradiation. Distant metastases were detected in two patients (one in lung and one in brain). One third (5 of 15) of the patients developed disease recurrence. Lymph node recurrence was detected in one patient 12 years after the initial operation. Over a median follow-up period of 10.7 years, one patient with an initial incomplete excision died of the carcinoma. The overall disease-specific survival rate was 93%.

CONCLUSIONS

DSV of PTC had distinctive clinicopathologic features and a high incidence of recurrence after operation but had a prognosis similar to that of classic PTC.

Prognostic factors for persistent or recurrent disease of papillary thyroid carcinoma with neck lymph node metastases and/or tumor extension beyond the thyroid capsule at initial diagnosis

CONTEXT

Reliable prognostic factors are needed in papillary thyroid cancer patients to adapt initial therapy and follow-up schemes to the risks of persistent and recurrent disease. OBJECTIVE AND SETTINGS: To evaluate the respective prognostic impact of the extent of lymph node (LN) involvement and tumor extension beyond the thyroid capsule, we studied a group of 148 consecutive papillary thyroid cancer patients with LN metastases and/or extrathyroidal tumor extension. Initial treatment, performed at the Institut Gustave Roussy between 1987 and 1997, included in all patients a total thyroidectomy with central and ipsilateral en bloc neck dissection followed by radioactive iodine ablation.

RESULTS

Uptake outside the thyroid bed, demonstrating persistent disease, was found on the postablation total body scan (TBS) in 22% of the patients. With a mean follow-up of 8 yr, eight patients (7%) with a normal postablation TBS experienced a recurrence. Ten-year disease-specific survival rate was 99% (confidence interval, 97-100%). Significant risk factors for persistent disease included the numbers of LN metastases (>10) and LN metastases with extracapsular extension (ECE-LN >3), tumor size (>4 cm), and LN metastases location (central). Significant risk factors for recurrent disease included the numbers of LN metastases (>10), ECE-LN (>3), and thyroglobulin level measured 6-12 months after initial treatment after T4 withdrawal.

CONCLUSION

We highlight an excellent survival rate and suggest risk classifications of persistent and recurrent disease based on the numbers of LN metastases and ECE-LN, LN metastases location, tumor size, and thyroglobulin level.

Diffuse sclerosing variant of papillary thyroid carcinoma: a clinicopathologic and immunophenotypic analysis of 22 cases

BACKGROUND

The diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is an uncommon tumor making up about 2% of all papillary thyroid carcinomas. Previous studies have not comprehensively evaluated these tumors in a large series of patients.

DESIGN

Twenty-two cases of DSV-PTC diagnosed between 1970 and 2000 were identified in the files of the AFIP. Histologic and immunohistochemical features were evaluated and patient follow-up was obtained.

RESULTS

The tumors affected 14 females and 8 males, aged 6 to 49 yr (mean, 18 yr), with males presenting at a mean older age than females (24 vs 14 yr). Symptoms included an enlarging mass in the thyroid, present for a mean of 9.5 mo. While a dominant tumor was identified in a single lobe, bilateral disease was common (n = 16). The dominant mass ranged in size from 1.7 to 5.8 cm in diameter (mean, 3.8 cm). Histologically, all cases demonstrated a papillary carcinoma (conventional, solid, or follicular pattern) diffusely involving the gland. Extrathyroidal extension, lymphocytic thyroiditis, squamous metaplasia, increased fibrosis/sclerosis, and psammoma bodies were present to a variable degree. Both the papillary carcinoma and squamous metaplasia cells were strongly immunoreactive with CK19, thyroglobulin, and TTF-1. An increased number of S-100 protein immunoreactive dendritic cells were recognized. p53 was increased (>15%) in the tumor cells in 12 patients, while Ki-67 was increased in the tumor cells in two patients. Perithyroidal and cervical lymph node metastasis occurred in 18 (82%) patients. All metastases demonstrated histologic features similar to the primary. Complete resection (thyroidectomy in 18 patients) with lymph node dissection, yielded a 95% 5-yr survival without evidence of disease. One patient died of disease after a malignant transformation of the squamous metaplasia into squamous cell carcinoma.

CONCLUSIONS

The recognition of DSV-PTC can be made with the following features: classic to solid foci of PTC, lymphocytic thyroiditis, squamous metaplasia, increased fibrosis, and innumerable psammoma bodies. DSV-PTC is more biologically aggressive than conventional PTC, but the patients' survival is not significantly different. This diagnosis should lead the clinician to aggressively manage these patients (thyroidectomy and lymph node dissection) in an effort to achieve an excellent long-term clinical outcome.

Predictive Factors for Recurrence from a Series of 74 Children and Adolescents with Differentiated Thyroid Cancer

The influence of clinical and treatment factors on the risk of recurrence was analyzed from a retrospective series of 74 children and adolescents with thyroid cancer (55 girls, 19 boys; age 2-20 years). Two groups, comparable in terms of age, sex, and previous radiotherapy, were compared according to the presence (group 1) or absence (group 2) of cervical lymph nodes identified by palpation or ultrasonography. Total thyroidectomy (TT) with lymph node dissection (LND) was performed in the 19 group 1 patients, whereas in group 2 patients (n = 55) lobectomy was performed in 29, TT in 26, and LND in 7. Pathology studies showed papillary thyroid carcinoma in 95% of cases. In group 1, tumors were more frequently multifocal (89% vs. 16% in group 2), invasive with extension beyond the thyroid capsule (68% vs. 5% in group 2), and of the diffuse sclerosing variety (63% vs. 4% in group 2) (p < 0.001). With a median follow-up of 61 months, lymph node recurrence was seen in 53% of group 1 patients and in no patients in group 2. Three group 2 patients (10%) were reoperated for a local recurrence after lobectomy. Risk factors for reintervention were young age (< 15 years) (p < 0.01) and cervical lymph nodes (p < 0.001). Survivals without reintervention at 5 and 10 years were, respectively, 58% and 38% for group 1 and 94% and 90% for group 2 (p < 0.001). At the time of analysis, 68% of group 1 patients and 98% of group 2 patients were in remission. In conclusion, the presence of palpable cervical lymph nodes at diagnosis is associated with more invasive forms of malignancy and is a predictive factor of recurrence regardless of the extent of the initial surgery.

Simultaneous diffuse sclerosis variant of papillary thyroid carcinoma and diffuse toxic hyperplasia (Graves' disease)

Diffuse sclerosis variant of papillary thyroid carcinoma (DSVPTC) is an unusual malignant neoplasm that typically permeates the entire gland resulting in diffuse thyroid enlargement. In the absence of a dominant nodule, DSVPTC can be histologically deceiving because of exuberant inflammation and the scattered distribution of the microscopic tumor islands. The difficulty in diagnosing this tumor is compounded by its rarity and unusual clinical and histologic features. Herein, we describe a unique case of DSVPTC that was clinically masked by a co-existing second diffuse thyroid process--Graves' disease (GD). A subtotal thyroidectomy was performed in a 27-yr-old Caucasian female who presented with symmetrical diffuse thyromegaly with neck compressive symptoms, thyrotoxicosis, and biochemical signs of GD. Histologic examination of the thyroid gland unexpectedly revealed extensive involvement by DSVPTC in addition to the diffuse hyperplastic non-malignant thyroid follicles. This report illustrates the histologic features as well as the diagnostic challenge encountered in a rare simultaneous occurrence of DSVPTC and GD.<P>

A review of thyroid cancer with intermediate differentiation

BACKGROUND AND OBJECTIVES

Tall cell (TCV), columnar cell (CCV), insular (IC), diffuse sclerosing (DSPTC) and solid/trabecular are uncommon subtypes of thyroid cancer, which have generally been described in case reports or small series in the world literature. Due to the rarity of these thyroid cancers, their clinical behavior remains incompletely understood. The aim of this review was to pool the currently available clinical information regarding these uncommon thyroid cancers so as to gain a better understanding of their clinical aspects and natural history.

METHODS

A computer-aided search of MEDLINE (1966-2001, PUBMED website) and CINAHL (1982-2001) databases was performed, as well as a review of the reference section of each primary study was done. All cases of TCV, CCV, DSPTC, solid/trabecular, and IC described in the English medical literature were identified. For the subtypes DSPTC, TCV, and IC, clinical data from the published case series were combined in a weighted analysis. Weighting was based on the number of cases per series. For the CCV and the solid/trabecular variant, due to the small number of cases, raw figures for the clinical features were obtained.

RESULTS

DSPTC (n = 65) appeared to have a tendency for intra-thyroidal extension (40%) and a high propensity for nodal metastates (68%). The mean overall tumor related mortality was similar to well differentiated thyroid cancer (WDTC) at only 2% at 8 years follow-up. The solid/trabecular variant was seen in 37% of the radiation induced thyroid tumors of the Chernobyl accident. It had a high propensity for extrathyroidal extension, and cervical lymph node metastases were found in up to 83% of patients. Unlike WDTC, TCV (n = 209) was a more aggressive tumor, associated with distant metastases in 22% of cases and had a mean tumor related mortality of 16%. The histological diagnosis of TCV was a poor prognostic factor regardless of patient age or tumor size. The CCV (n = 41) had a high overall mortality rate of 32%. When encapsulated, however, CCV had an excellent prognosis similar to that found in WDTC. In contrast, CCV tumors that were not encapsulated had extrathyroidal spread in 67% and had distant metastases in 87% of patients. The variant of IC (n = 213) appeared to be an aggressive subtype of thyroid cancer. The mean loco-regional recurrence and/or distant metastases rate was 64% and tumor related mortality was high at 32%.

CONCLUSIONS

DSPTC, TCV, CCV, and IC are thyroid cancer subtypes, which have a biological aggressiveness, which appear to be intermediate between that of WDTC and poorly differentiated anaplastic thyroid cancer. J. Surg. Oncol. 2004;86:44-54.

Diffuse sclerosing variant of papillary thyroid carcinoma--clinical features and outcome

AIM

Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is rare and occurs in young patients. This is a single institute retrospective analysis to report the clinical features and outcome of DSPC.

METHOD

DSPC constituted 8 (0.74%) of 1086 papillary thyroid carcinomas (PTC) referred to the department of Clinical Oncology, Queen Elizabeth Hospital Hong Kong from 1960 to 2000.

RESULTS

The mean follow-up was 8 years (range: 1.4 to 15.2 years). Six were females and two were males, with age ranging from 11 to 48 years. All were ethnic Chinese. Compared with the whole cohort of PTC followed in the same period, these patients showed younger age at presentation (mean 27.4 vs 45.3 years), larger tumor size (mean 6.9 cm vs 2.4 cm), higher incidence of lymph node metastasis (100% vs 32.4%), and more frequent presence of serum anti-thyroglobulin autoantibody (75% vs 11.3%). The patients were managed as for differentiated thyroid carcinoma according to the institute's protocol, including total thyroidectomy followed by radioiodine (RAI) treatment. External radiotherapy was given to two patients as primary treatment and one patient after regional relapse. One patient had distant metastases at presentation and she was successfully treated by surgery followed by RAI, remaining in complete remission at 12.1 years. One patient had lymph node recurrence after primary total thyroidectomy and RAI treatment and was successfully salvaged by surgery and external radiotherapy. At last follow-up, all eight patients were alive with no evidence of disease.

CONCLUSIONS

Although DSPC is associated with some unfavourable features at presentation (such as large tumor size, extensive lymph node metastasis), the prognosis appears to be as good as classical PTC. After aggressive treatment by radical surgery, RAI ablation and/or external radiotherapy, the outcome and survival was excellent.

Diffuse sclerosing variant of papillary thyroid carcinoma with primary squamous cell carcinoma

A case of a very rare combination of diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) and primary squamous thyroid carcinoma (PSC) is presented. A 25-yr-old woman with right-sided neck mass and hypothyroidism was admitted. US showed that the right lobe of the thyroid gland was enlarged with irregular margins and heterogen echogenity and there were multiple small punctate echogenic foci in the central portion. A scintigraphy with 99mTc showed decreased uptake in the right lobe. FNA of the right lobe induced us to consider the presence of follicular neoplasm. Chest roentgenogram was normal. Total thyroidectomy with right-sided modified radical neck dissection was performed. Findings related to Hashimoto's thyroiditis and abundant psammoma bodies were observed in the frozen sections. Histopathologic findings demonstrated the coexistence of DSPC and PSC in both lobes and 16 lymph nodes metastases and soft tissue infiltration. Radioiodine was administered to ablate residual thyroid tissue. She was given T4 suppression therapy. At the 44th month of follow-up, she remains well without recurrences and metastases. The coexistence of DSPC and thyroiditis or PSC is still under debate. Very few cases with the combination of papillary thyroid carcinoma and PSC have been reported previously, thus we discuss the clinico-pathologic features and possible explanation for this unusual coexistence of malignancies.

Occult papillary carcinoma of the thyroid gland with extensive osseous metastases--a case report with review of the literature

The authors report a case of extensive osseous metastases from a clinically occult papillary carcinoma of the thyroid gland without evidence of regional lymph node metastases. Some features of the primary tumour, namely focal "tall-cell" morphology and higher nuclear grade, raise the possibility of including such a tumour into the poorly differentiated category of thyroid carcinomas. Literature review only disclosed one similar reported case.

Clinical forms of presentation and evolution of diffuse sclerosing variant of papillary carcinoma and insular variant of follicular carcinoma of the thyroid

We investigated whether the diffuse sclerosing variant of papillary carcinoma (diffuse sclerosing PC) and insular carcinoma (IC), two different subforms of differentiated carcinoma of the thyroid gland, have different clinical behaviors and prognosis in order to select appropriate therapy. The characteristics of clinical presentation, and outcome after therapy were evaluated in a series of 113 patients (18 males and 95 females) with differentiated thyroid carcinoma treated with the same protocol, of which 7 had diffuse sclerosing PC and 6 had IC; within this series, patients with diffuse sclerosing PC and IC were compared with 76 cases of papillary carcinoma (PC) and 24 cases of follicular carcinoma (FC), respectively. Diffuse sclerosing PC patients were younger (23+/-9 vs. 38+/-16 years) and had a higher degree of lymphatic metastases at diagnosis (100%) than patients with PC (47%). Five of 7 patients with diffuse sclerosing PC were alive and without evidence of disease compared to 34 of 76 patients with PC at follow-up (6.4+/-5.1 and 7.9+/-7 years, respectively). No prognostic differences were found between them. IC showed a more advanced stage of disease at diagnosis and a more aggressive clinical course with a higher percent of metastases and mortality than patients with FC at follow-up (1 patient died and 5 were alive with persistent disease at 4.8+/-3.7 years for IC; 22 were alive, 13 of them with persistent disease; and 2 died at 8.4+/-5.3 years for FC). We conclude that patients with diffuse sclerosing PC do not require a different treatment than that given to PC patients, while in contrast, IC cases need a more aggressive therapeutic approach.

Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma: Case Report and Review of the Literature

OBJECTIVE

To describe a patient with a diffuse sclerosing variant of papillary (DSVP) thyroid cancer and to summarize the reported clinical manifestations and treatment of other patients with this malignant tumor.

METHODS

We reviewed the pathologic findings in a 14-year-old girl, who had survived for 19 years after treatment of a presumed undifferentiated thyroid cancer. When reassessment revealed histologic features of DSVP cancer, we reviewed the case reports of this type of malignant lesion identified from a MEDLINE search of articles published between 1985 and 1995.

RESULTS

Review of the pathologic features showed a diffuse tumor in the thyroid gland without an identifiable mass and extensive bilateral lymph node metastatic lesions. Histologic examination disclosed pronounced fibrosis, numerous psammoma bodies, primarily a solid growth pattern, lymphocytic infiltration, and extensive invasion of lymphatic spaces. The nuclear features were characteristic of papillary carcinoma. Review of 63 cases of DSVP cancer indicated that this variant accounted for 0.2 to 5.7% of papillary cancer, affected primarily young women, and usually manifested with diffuse involvement of one or both thyroid lobes. Thyroid antibodies were frequently detected in the serum. Cervical lymph node metastatic lesions, local invasion, and distant metastatic involvement were described in 75, 35, and 16% of patients, respectively. Although the cancer recurred in 37% of patients, only two died of this malignant tumor.

CONCLUSION

DSVP cancer can be confused with nontoxic goiter, chronic thyroiditis, nonthyroidal malignant tumors, or undifferentiated thyroid cancer. We suggest that the same therapy used for young patients with conventional papillary thyroid cancer is also appropriate for most patients with the diffuse sclerosing variant.

Diagnostic problems in differentiated carcinomas of the thyroid

In this review article we consecutively address the following issues: differential diagnosis of follicular adenomas and minimally invasive follicular carcinomas, with a special emphasis on the hyalinizing trabecular tumours; differential diagnosis of benign and malignant papillary lesions; individualization of the variants of papillary carcinoma that carry a guarded prognosis; differential diagnosis of differentiated thyroid carcinomas exhibiting foci of other types of thyroid carcinoma, namely mucoepidermoid and poorly differentiated carcinoma; and, finally, the diagnostic problems raised by the so-called mixed medullary-follicular carcinomas.