Papillary Carcinoma of the Thyroid Gland with Nodular Fasciitis-like Stroma

Papillary thyroid carcinoma with desmoid-type fibromatosis: the clinicopathological features with characteristic imaging and molecular correlation requiring comprehensive treatment

The pathogenesis and treatment of papillary thyroid cancer with desmoid-type fibromatosis (PTC-DTF), a rare subtype of papillary thyroid carcinoma characterized by a mixed epithelial-mesenchymal structure, are still ill-defined. Previous reports on PTC-DTF have had limited follow-up and recurrence has been rarely reported. To better understand this condition, we conducted a thorough analysis of five cases of PTC-DTF from our institute, including clinical and pathological examinations, imaging, immunohistochemistry, and molecular analysis. We also reviewed relevant literature. The mean age of the patients was 51.8 years, with three women and two men included in the group. Ultrasound often showed a hypoechogenic and well-defined nodule in the thyroid gland, except for one individual who had distant lung metastases detected by PET-CT. The nodules ranged in width from 0.5 to 5.0 cm and were excised in each case. Following surgery, ¹³¹I therapy was used in two cases. The overall number of PTC-DTF cases has risen from the previously reported 55 to 60, with females being the most commonly affected and ranging in age from 19 to 82. Most masses underwent a thyroidectomy, and approximately half of the patients had lymph node metastases. Histologically, PTC-DTFs were composed of a predominant stromal component (65% - 90%) and an intervening epithelial component. These spindle cells were arranged in parallel with abundant cytoplasm and vacuole-like nucleus but there wasn't evident atypia. The carcinoma cells were positively stained for CK and TTF-1 by immunohistochemistry, whereas mesenchymal cells were positive for SMA and displayed nuclear immunoreactivity for β-catenin. BRAF, NRAS, and CTNNB1 mutations were identified in the epithelial and mesenchymal components through molecular testing, respectively. Perhaps because the mesenchyme harbors aberrant nuclear β-catenin expression, PTC-DTF is more aggressive and prone to invasion and distant recurrence, as shown by our case 2, which is the first case to be reported thus far. PTC-DTF is typically treated with surgery, but clinicians may occasionally consider more holistic treatment plans that involve radioactive iodine and endocrine therapy.

Papillary Thyroid Carcinoma with Desmoid-Type Fibromatosis: Review of Published Cases

Simple Summary

Papillary thyroid cancer (PTC)-desmoid type fibromatosis (DTF) is one of the rarest variants of PTC. The diagnosis is histological, and detecting a mutation of CTNNB1 in the mesenchymal component is highly suggestive of PTC-DTF. The treatment is essentially surgical. We conducted a review of all cases of PTC-DTF found in the English literature and our aim is to describe patient’s characteristics, histology, immunohistochemistry and somatic mutations of every case.

Abstract

Desmoid-type fibromatosis (DTF) is a very rare variant of papillary thyroid carcinoma (PTC). It is essentially a dual tumor with a component of classical PTC with malignant epithelial proliferation (BRAF-mutated) and another component of mesenchymal proliferation (CTNNB1-mutated). We conducted a literature review on PTC-DTF. In total, 31 articles were identified, that together reported on 54 patients. The mean age was 47 years, with a 2.2:1 female predominance. No ultrasound features were found to be helpful in differentiating PTC-DTF from other PTC variants. Of the 43 cases that reported histological details, 60% had locally infiltrative disease (T3b or T4). Around 48% had cervical lymph node metastases, but none had distant metastases. While PTC-DTF may be locally more aggressive than classic PTC, its overall behavior is similar and can include extrathyroidal extension and lymph node metastases, which may contain a stromal component and show extranodal invasion. The mainstay of treatment for PTC-DTF is surgery, and the DTF component is not expected to be sensitive to radioactive iodine. External radiotherapy, non-steroidal anti-inflammatory drugs, tyrosine kinase inhibitors and chemotherapy have also been used in selected cases. Due to the rarity of these tumors and the lack of specific treatment guidelines, management should be discussed in a multidisciplinary team.

Case of medullary thyroid carcinoma with desmoid-type fibromatosis

A 36-year-old man was admitted to hospital for a right thyroid nodule incidentally discovered on a chest computed tomography scan for a rib fracture. He had no history of radiation to the head and neck, no known family history of endocrine disease, and no medical or surgical history. A 17 × 10 mm, well-demarcated, multinodular, whitish nodule with neither necrosis nor hemorrhage was found in the right thyroid. Microscopically, the tumor consisted of epithelial cell nests with oval, plasmacytoid or polygonal cells with speckled chromatin, inconspicuous nucleoli and granular cytoplasm. The surrounding stroma showed amyloid deposition and prominent spindle cell proliferation with myxoid substance. Epithelial cell nests showed an immunoreactive pattern for typical medullary thyroid carcinoma (MTC), and the spindle cell stroma showed nuclear expression of beta-catenin. This may be the first report on histopathologic findings of MTC with desmoid-type fibromatosis. Further studies are necessary to discover the clinicopathologic characteristics and pathogenesis of this rare type of tumor.

Papillary thyroid cancer with extrathyroidal extension of desmoid-type fibromatosis. A case report of an aggressive presentation of an uncommon pathologic entity

INTRODUCTION

Papillary thyroid cancer with desmoid-type fibromatosis (PTC-DTF) is an uncommon tumor characterized by extensive stromal proliferation of fibroblasts and myofibroblasts with a small component of PTC. We report a case of PTC-DTF with infiltration of the mesenchymal component of tumor into perithyroidal muscle and early recurrence of desmoid after thyroidectomy, an outcome previously not reported.

PRESENTATION OF CASE

A 20-year-old man underwent left hemithyroidectomy for a thyroid nodule. Pathology demonstrated a 4.2 cm tumor with PTC-DTF with the PTC comprising <10% of the tumor. The stromal component extended into adjacent skeletal muscle. After completion thyroidectomy, histopathology of the right thyroid lobe revealed no malignancy or fibromatosis. Neck MRI 16 months after the initial operation revealed a 10.5 cm tumor in the left thyroid bed. Core biopsy and open excisional biopsy showed desmoid-type fibromatosis without PTC. The patient is undergoing chemotherapy of his recurrent desmoid-type fibromatosis.

DISCUSSION

In patients with PTC-DTF there is a risk of recurrence of the benign component of the tumor. In recent reports, the role of less aggressive surgery, or even non-surgical management, of patients with recurrent DTF has been emphasized, in particular when extensive surgery may be associated with high risk of functional loss. The management of our patient adheres to modern recommendations for the treatment of DTF.

CONCLUSION

Patients with PTC-DTF should be carefully monitored after thyroidectomy for both recurrent PTC and local recurrence of the fibrous component of the tumor.

SOX11 expression in a case of papillary thyroid carcinoma with fibromatosis/fasciitis-like stroma containing BRAF c.1799_1801delTGA and CTNNB1 c.133T>C mutations

We describe a case of papillary thyroid carcinoma with fibromatosis/fasciitis-like stroma (PTC-FLS) that contained the rare BRAF c.1799_1801delTGA (p.V600_K601delinsE) mutation, which has not previously been reported in this tumour, as well as the CTNNB1 c.133T>C (p.S45P) mutation. We also report the novel observation that spindle cells of the mesenchymal component exhibit diffuse nuclear but not cytoplasmic expression of SOX11, whereas the malignant epithelial cells did not. This suggests that immunoreactivity for SOX11 can be an alternative diagnostic tool for evaluating cases of PTC-FLS where the nuclear expression of β-catenin is ambiguous.

Can Ultrasound Alone Predict Papillary Thyroid Carcinoma with Desmoid-Type Fibromatosis? A Retrospective Analysis of 13 Cases, Focusing on the Stromal Area

Purpose

Papillary thyroid carcinoma with desmoid-type fibromatosis (PTC-DTF) is extremely rare. So far, only 4 cases describing the ultrasound findings of this variant have been reported. Here, we describe the ultrasound findings of 13 cases of PTC-DTF, focusing especially on the DTF area.

Materials and Methods

We retrospectively analyzed the clinical reports, ultrasound reports, and ultrasound photographs obtained from medical records at Kuma Hospital.

Results

The patients included 8 women and 5 men with a mean age of 47.9 years. The widest dimension of the nodules ranged from 16 to 79 mm (mean: 37.5 mm). The original ultrasound reports classified the nodules as either intermediate suspicion or high suspicion. A diagnosis of PTC was suspected in 12 nodules, and anaplastic carcinoma was suspected in 1 nodule. PTC-DTF presented with an irregularly shaped nodule (100%), taller-than-wide sign (84.6%), heterogeneous echogenicity (100%), no microcalcification (76.9%), and no or mild flow signal on Doppler (75.0%). The DTF area was identified in the ultrasound photographs of 8 nodules. DTF areas were generally heterogeneous (62.5%) and more hypoechoic (71.4%) than PTC areas. Microcalcification was not observed in the DTF areas. All of the DTF areas revealed no or mild flow signal. On ultrasound elastography, the DTF areas were not stiff, and they were more elastic than the PTC areas.

Conclusion

It is difficult to predict PTC-DTF using ultrasound alone, and B-mode ultrasonography is more reliable than ultrasound elastography in the ultrasound diagnosis of malignant thyroid nodules.

Papillary thyroid carcinoma with nodular fasciitis-like stroma and β-catenin gene mutations: report of a recurrent case

Papillary thyroid carcinoma with nodular fasciitis-like stroma (PTC-NFS) is a rare lesion with dual pathological features, that behaves more aggressively if positive for β-catenin gene (CTNNB1) mutations. Recently, we encountered a recurrent PTC-NFS with CTNNB1 mutations. A 48-year-old female presented with a recurrent enlarging tumor with a diagnosis of desmoid-type fibromatosis 6 months after her initial operation for PTC-NFS. Over a 2-year observation period, she underwent remedial surgery to resect the recurrent tumor. During the operation, the left recurrent laryngeal nerve was engulfed and scarified. Local invasion, β-catenin aberrant staining, and CTNNB1 mutations were detected both in the primary tumor stroma and the recurrent tumor. This case indicates that CTNNB1 mutation screening and β-catenin staining should be performed in PTC-NFS cases as a predictor for recurrence. If either of these are positive, a wider surgical resection should be adopted to achieve negative margins. Otherwise, radiotherapy should be considered. Furthermore, the lesion might be better known as papillary thyroid carcinoma with desmoid-type fibromatosis in such situations to reflect its local aggressive nature.

Papillary thyroid carcinoma with desmoid-type fibromatosis: A clinical, pathological, and immunohistochemical study of 14 cases

Papillary thyroid carcinoma (PTC) with desmoid-type fibromatosis (DTF) is characterized by genetic alterations of the fibroblasts. PTC-DTF is extremely rare, and the reports on such cases have been sporadic. Immunohistochemical staining using the antibody for beta-catenin is useful in diagnosing the variant. This report aims to describe the clinical, pathological, and immunohistochemical findings in 14 cases of PTC-DTF and to clarify the diagnostic significance of the variant. The patients included 9 women and 5 men, with a mean age of 49.3 years. PTCs with focal DTF components and with extensive DTF components included 7 cases each. No significant differences were noted in terms of age, gender, and serum thyroglobulin levels between extensive and focal DTF cases. On aspiration cytology, 12 cases were reported as suspicious for malignancy or malignant, and schwannoma or fibroma was suggested in 1 case each. The DTF components were histologically classified into 4 types, namely, central (4 cases), peripheral (1 case), mixed (7 cases), and diffuse type (2 cases). The stromal components were consistent with those of DTF. Immunohistochemically, fibroblasts in the DTF components showed nuclear and cytoplasmic expression for beta-catenin in 12 cases. The features are observed even in cases in which stromal components focally exist. Neither carcinoma cells nor the fibroblasts with Ki-67 labeling index >5% were found in all cases. We agree that PTC with nodular fasciitis-like stroma should be renamed to PTC-DTF.

Papillary thyroid carcinoma with nodular fasciitis-like stroma and β-catenin mutations should be renamed papillary thyroid carcinoma with desmoid-type fibromatosis

Various histological variants of papillary thyroid carcinoma have been reported, some with clinical implications, some with peculiar, sometimes misleading morphologies. One of these rare and poorly characterized variants is papillary thyroid carcinoma with nodular fasciitis-like stroma, of which fewer than 30 cases have been documented, mostly as isolated reports. It is a dual tumor comprising a malignant epithelial proliferation that harbors typical features of conventional papillary thyroid carcinoma, admixed with a prominent mesenchymal proliferation resembling nodular fasciitis or fibromatosis. Thus, the terms papillary thyroid carcinoma with nodular fasciitis-like stroma and papillary thyroid carcinoma with fibromatosis-like stroma are used interchangeably; however, the former term suggests a self-limited and regressing disease, whereas the latter one suggests a recurrent and potentially aggressive one. Better genetic and ultrastructural characterization could lead to more appropriate terminology and management. We performed detailed clinicopathological and molecular analyses of two cases of PTC with prominent mesenchymal proliferation that developed in the thyroid gland of two male patients aged 34 and 48. In both cases, the epithelial component harbored a heterozygous somatic activating BRAF mutation (p.V600E). Also, in both cases, the mesenchymal component showed typical aberrant nuclear and cytoplasmic immunoreactivity for β-catenin and harbored a heterozygous somatic activating mutation in the corresponding CTNNB1 gene (p.S45P). This mutation has never been reported in thyroid stroma; in other tissues, it is typical of desmoid-type fibromatosis rather than nodular fasciitis-like stroma. We therefore propose that in cases of papillary thyroid carcinoma with a prominent mesenchymal component, mutations in CTNNB1 should be sought; when they are present, the term 'papillary thyroid carcinoma with desmoid-type fibromatosis' should be used. As the mesenchymal component of these tumors is not expected to concentrate radioactive iodine, special considerations apply to clinical evaluation and follow-up, which should be brought to the attention of the treating specialist.

Stromal modulation and its role in the diagnosis of papillary patterned thyroid lesions

The papillary patterned lesion of thyroid may be challenging with many diagnostic pitfalls. Tumor stroma plays an important part in the determination of the tumor phenotype. CD34 is thought to be involved in the modulation of cell adhesion and signal transduction as CD34(+) fibrocytes are potent antigen-presenting cells. Smooth muscle actin (SMA) positivity could be diagnostic for fibroblast activation during tumorigenesis. We aimed to examine the expression of CD34 and alphaSMA in the stroma of papillary thyroid hyperplasia, papillary thyroid carcinoma and papillary tumors of uncertain malignant potential in order to elucidate their possible differential distribution and roles. A total number of 54 cases with papillary thyroid lesions were studied by routine HandE staining, CD34 and ASMA immunostaining. ASMA was not expressed in benign papillary hyperplastic lesions while it was expressed in papillary carcinoma, indicating that tumors have modulated stroma. Although the stroma was not well developed in papillary lesions with equivocal features of uncertain potentiality, CD34 was notable in such cases with higher incidence in malignant cases. So ASMA as well as CD34 could predict neoplastic behavior, pointing to the importance of the stromal role. Differences between groups suggest that the presence of CD34 + stromal cells is an early event in carcinogensis and is associated with neoplasia, however ASMA+ cells are more likely to be associated with malignant behavior and metastatic potential adding additional tools to the light microscopic picture helping in diagnosis of problematic cases with HandE.

Squamous cell carcinoma of the lung with highly proliferating fibromatosis-like stroma: a rare phenomenon

Few cases of carcinoma with exuberant stromal proliferation have been documented, apart from scirrhous carcinoma. To the best of our knowledge, previous cases of carcinoma exhibiting exuberant stromal proliferation have exclusively been reported in the thyroid gland, specifically as papillary carcinoma. The exuberant stromal proliferation has been recognized to be similar to either fibromatosis or nodular fasciitis. Herein, we report a case of a 74-year-old Japanese man whose tumor in the upper lobe of his right lung displayed highly proliferating stroma with dispersed, poorly differentiated squamous cell carcinoma nests. The stromal spindle cells (fibroblasts/myofibroblasts) had similar molecular profiles to those typically observed in fibromatosis rather than nodular fasciitis, resulting in the designation of "fibromatosis-like" stroma. The presence of carcinoma cells, along with stromal cells, expressing TGF-β in this case likely fostered continuous stromal proliferation, presumably in conjunction with the unique microenvironment in which the carcinoma cells were present.

Papillary thyroid carcinoma with nodular fasciitis-like stroma: a usual entity with distinctive morphology

Papillary thyroid carcinoma (PTC) is a common malignancy with multiple variants, some of which are rarely encountered in routine surgical pathology practice. PTC with exuberant nodular fasciitis-like stroma (PTC-NFS) or PTC with fibromatosis-like stroma (PTC-FMS) is one such variant. We report a case of PTC-NFS, a tumor characterized by an abundant stromal component with an intervening epithelial component with the typical morphologic features of conventional PTC. We review the literature on this rare variant, discuss the importance of a thorough search for epithelial components within any fibroproliferative lesion of the thyroid, and address the diagnostic difficulties created by the tumor's extensive stromal component.

Notch and TGF-β/Smad3 pathways are involved in the interaction between cancer cells and cancer-associated fibroblasts in papillary thyroid carcinoma

Accumulating evidence suggests that cancer-associated stromal fibroblasts (CAFs) contribute to tumor growth by actively communicating with cancer cells. Our aim was to identify the signaling pathways that are involved in tumor-stromal cell interactions in human papillary thyroid carcinoma (PTC). Immunohistochemical analyses were performed with 127 archived formalin-fixed and paraffin-embedded thyroid tissue samples that included 70 cases of PTC, 35 cases of nodular goiter (NG), and 22 cases of normal thyroid tissues. The results showed that the expression levels of Notch1, transforming growth factor β (TGF-β1), and p-Smad3 in PTC cells and α-smooth muscle actin (α-SMA) in the stroma of PTC were all significantly higher than in NG and normal thyroid tissues. Further analysis showed that in PTC, higher expression levels of Notch1 and TGF-β1 were closely related with lymph node metastasis (P < 0.05), whereas for α-SMA and p-Smad3, the percent expression increased significantly with advanced tumor stages (P < 0.05). Correlation analysis revealed that TGF-β1 expression increased with increased Notch1 and p-Smad3 levels in PTC cells (P < 0.05). Moreover, a significant correlation was found between higher TGF-β1 expression in PTC cells and increased α-SMA levels in the fibroblasts surrounding the cancer cells (P < 0.05). We identified TGF-β1 as an important factor from PTC cells that act in a paracrine manner to influence the activation of stromal fibroblasts. These data suggest that the activation of Notch and TGF-β/Smad3 pathways in cancer cells influence tumor growth. Moreover, cancer cell-derived-TGF-β ligands also affect stromal cells in a paracrine fashion and enhance tumor growth.