Case report: Different metastatic components from anaplastic thyroid carcinoma in mediastinal and neck lymph nodes simultaneously diagnosed by FNA

Anaplastic thyroid carcinoma (ATC) is a rare but aggressive form of undifferentiated thyroid carcinoma which arises from previously well‐differentiated thyroid carcinomas, such as papillary carcinoma or follicular carcinoma. We report on an interesting case of ATC found in an enlarging neck mass with metastatic papillary carcinoma found in mediastinal lymph nodes sampled by endoscopic bronchial‐ultrasound guided‐ fine‐needle aspiration, due to the incidental finding of a lung mass by CT scan. Divergent morphologies on cytology preparations were resolved by immunohistochemistry, which aided in the identification of both sites of malignancy and the common thread between them. The eventual palliative resection demonstrated the various components including undifferentiated thyroid carcinoma, papillary carcinoma, and background lymphocytic thyroiditis. Diagn. Cytopathol. 2014;42:694–699. © 2013 Wiley Periodicals, Inc.     

Immunohistochemical detection of epithelialmesenchymal transition associated with stemness phenotype in anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is a highly aggressive neoplasm resistant to radiation and chemotherapy. Epithelial-mesenchymal transition (EMT) generating cells with stem cell characteristics have been reported to be associated with chemoradioresistance in cultured cells. However, EMT and stem cell properties in ATC have not been fully investigated. In this study, we retrieved 2 thyroidectomy specimens of ATC with coexisting well differentiated thyroid carcinomas (DTCs) including one papillary carcinoma (PTC) and one follicular carcinoma (FTC). We used im-munohistochemistry to examine the expression of stem cell markers (nestin, CD133 and CD44) and a marker for EMT (E-cadherin). Intense expressions of nestin, CD133 and CD44, and no expression of E-cadherin were observed in both ATCs. In contrast, the PTC and FTC, and non-neoplastic thyroid tissue in both cases were negative for nestin and positive for E-cadherin. The expressions of CD133 and CD44 were variable in the PTC, FTC, and non-neoplastic thyroid tissue and were at a lower level of expression of these markers in the overall pattern. The results confirmed EMT, demonstrated the stem cell phenotype in ATC, and revealed the difference in expression of these markers between ATC and DTCs/non-neoplastic thyroid tissue. Nestin may be the most specific marker for stemness in ATC by immuno-histochemial staining. The results warrant future studies on a large series of cases in order to gain the understanding of the tumor biology and to provide molecular basis for restoring the sensitivities to clinical therapies.     

Whole-genome sequencing of synchronous thyroid carcinomas identifies aberrant DNA repair in thyroid cancer dedifferentiation

The genetics underlying thyroid cancer dedifferentiation is only partly understood and has not yet been characterised using comprehensive pan-genomic analyses. We investigated a unique case with synchronous follicular thyroid carcinoma (FTC), poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma (ATC), as well as regional lymph node metastases from the PDTC and ATC from a single patient using whole-genome sequencing (WGS). The FTC displayed mutations in CALR, RB1, and MSH2, and the PDTC exhibited mutations in TP53, DROSHA, APC, TERT, and additional DNA repair genes – associated with an immense increase in sub-clonal somatic mutations. All components displayed an overrepresentation of C>T transitions with associated microsatellite instability (MSI) in the PDTC and ATC, with borderline MSI in the FTC. Clonality analyses pinpointed a shared ancestral clone enriched for mutations in TP53-associated regulation of DNA repair and identified important sub-clones for each tumour component already present in the corresponding preceding lesion. This genomic characterisation of the natural progression of thyroid cancer reveals several novel genes of interest for future studies. Moreover, the findings support the theory of a stepwise dedifferentiation process and suggest that defects in DNA repair could play an important role in the clonal evolution of thyroid cancer. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Pitfalls in the surgical pathologic diagnosis of papillary thyroid carcinoma

While the surgical pathology examination of the thyroid gland for papillary carcinoma may seem, on its surface, to be relatively straightforward, in reality it is fraught with diagnostic traps. Avoidance of these pitfalls is necessary for guiding the surgeon and endocrinologist to the appropriate treatment and follow up. This review will detail a selected group of some of the more commonly encountered challenges in making the diagnosis of papillary thyroid carcinoma from a busy head and neck pathology consultation practice.     

Emergency total thyroidectomy for bleeding anaplastic thyroid carcinoma: a viable option for palliation

Anaplastic thyroid carcinoma (ATC) is a rare and highly aggressive thyroid neoplasm. Bleeding from tumor is an uncommon, but potentially life-threatening complication requiring sophisticated intervention facilities which are not usually available at odd hours in emergency. We report the case of a 45-year-old woman who presented with exsanguinating hemorrhage from ATC and was treated by emergency total thyroidectomy. The patient is well three months postoperatively. Emergency total thyroidectomy is a viable option for palliation in ATC presenting with bleeding.     

Diagnostic challenges in thyroid cytopathology

Fine needle aspiration (FNA) is a long-standing modality used to obtain diagnostic material from patients with thyroid nodules. However, some common and uncommon situations exist in which diagnostic categorization of an FNA specimen is not straightforward. Diagnostically challenging thyroid lesions are typically either benign entities with cytomorphology that mimics malignancy, or malignant entities with unusual cytomorphology that causes difficulty in classification. Awareness of such diagnostic challenges can help broaden one's differential diagnosis when encountering such lesions on FNA. However, in many instances a definitive diagnosis may not be possible and providing an indeterminate diagnosis is most appropriate.     

促甲状腺激素受体及碘钠泵在人甲状腺癌中的表达及临床意义

目的 研究促甲状腺激素受体(TSHR)、碘钠泵(NIS)在甲状腺癌中的表达,探讨其在人甲状腺癌治疗中的作用. 方法采用免疫组织化学SABC法,检测TSHR、NIS在45例人正常甲状腺组织、45例乳头状甲状腺癌及21例未分化甲状腺癌中的表达. 结果 TSHR及NIS在人正常甲状腺组织的表达均高于其在乳头状甲状腺癌和未分化甲状腺癌中的表达.在人正常甲状腺组织,TSHR和NIS蛋白均定位于滤泡上皮细胞膜上;在乳头状甲状腺癌组织,TSHR蛋白定位于细胞膜和细胞质中,NIS蛋白仅在细胞质中有阳性表达;在未分化甲状腺癌,TSHR和NIS均定位于细胞质. 结论 TSHR、NIS的定位及表达水平与甲状腺癌的分化程度密切相关,可能成为预测甲状腺癌促甲状腺激素抑制治疗及131Ⅰ治疗是否有效的指标.     

Atypical adenoma of the thyroid diagnosed as anaplastic cancer by cytopathology

Atypical adenoma of the thyroid is a rare form of tumor, and its accurate diagnosis prior to surgical resection is difficult as the histological and pathological morphologies are very similar to those of anaplastic thyroid carcinoma (ATC), and its anaplastic transformation remains to be elucidated. We reported a case of a 75‐year‐old female with a thyroid isthmus nodule diagnosed repeatedly by FNAC as anaplastic carcinoma. Both the first and second FNAC specimen slides showed a large number of scattered or aggregated atypical cells consisting of large, pleomorphic nuclei with irregular membranes, chromatin clumps and prominent nucleoli. The morphology of the surgical specimen was similar to that of an anaplastic carcinoma and although it showed signs of transition from a normal follicular epithelium, there was no invasive growth or mitosis. This lesion was diagnosed as an atypical adenoma, and a papillary carcinoma was also present in the right lobe of the thyroid. Here we evaluate the molecular features of atypical adenomas in comparison with 9 ATC samples, and discuss whether or not atypical adenomas represent a form of premalignant lesion. Ki‐67 expression was found to be very low in atypical adenomas whereas all ATC samples showed high levels of Ki‐67 expression. Epithelial–mesenchymal transition (EMT) marker expression suggested that atypical adenomas maintain their epithelial phenotype to a higher degree than do ATCs. Differential diagnosis between ATC and atypical adenoma is difficult by cytological and histological methods alone, and Ki‐67 and EMT marker expression may support the diagnosis.     

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET–PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular‐patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non‐invasive follicular thyroid neoplasm with papillary‐like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen‐activated protein kinase and phosphoinositide 3‐kinase–PTEN–AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.     

Simultaneous papillary carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid; a case report

Primary lymphoma of the thyroid is an uncommon malignancy, whereas papillary thyroid carcinoma is the most common thyroid malignancy. Both have an association with Hashimoto's thyroiditis. We discuss a case of an 83 year old male who presented with a large neck swelling, which subsequently proved to be a primary thyroid lymphoma (extra-nodal marginal zone) with concurrent papillary thyroid carcinoma. These tumours manifested on a background of Hashimoto's thyroiditis. To date there have only been 13 other cases of joint papillary thyroid carcinoma and thyroid lymphoma within the literature. Our case report adds to this by discussing diagnosis, histopathological features and pitfalls in early detection.     

甲状腺癌相关microRNA

甲状腺癌是内分泌系统最常见的恶性肿瘤,包括4种病理类型,其中以乳头状癌及滤泡状癌最为常见。甲状腺癌的发病机制目前尚未阐明。近年来,研究发现在不同甲状腺癌病理类型中存在microRNA表达差异,microRNA可能在甲状腺癌的发生、发展中具有重要作用。     

Occult thyroid carcinoma: a rare case report and review of literature

Occult thyroid carcinoma is very common in the clinic and is generally divided into four groups. Here, we proposed two types of occult thyroid carcinoma as the fifth group. The first type was locoregional lymph node metastases from thyroid carcinoma, and the second type was distant organ metastases from thyroid carcinoma. The unique aspect of the fifth group was that the primary carcinoma of the fifth group was not finally found by pathological examination. To better understand the fifth group, we reported a typical case. Furthermore, we discussed the diagnostic criteria and procedures and the management of the fifth group of occult thyroid carcinoma.     

Histopathologic and immunohistochemical characterization of a primary papillary thyroid carcinoma in the lateral cervical lymph node

Lymph nodes in the neck are known to occasionally contain benign epithelial inclusions and can be rare primary site of various tumors usually occurring in other organs. Papillary thyroid carcinoma in the lateral neck lymph node with co-existing ectopic thyroid inclusions has not been reported previously. A 41-year-old male patient, who had normal thyroid function and no history of neck irradiation, was seen with a slowly enlarging mass in the right lateral neck. At surgery the cervical mass was found to be separate from the thyroid proper without any attachments in between. Papillary thyroid carcinoma and co-existing thyroid inclusions were identified within the lateral cervical lymph node. Immunohistochemistry detected strong and diffuse cytoplasmic positivity with antibodies against CK19 and CK903 in papillary thyroid carcinoma. Benign thyroid follicles within the lymph node were only weakly and focally stained. Thorough examination confirmed no malignancy in the total thyroidectomy specimen. Furthermore, small foci of metastatic papillary carcinoma were identified in two ipsilateral lymph nodes from neck dissection specimen. These findings suggest development of primary papillary thyroid carcinoma from malignant transformation of benign intranodal thyroid inclusions.     

A review of the cytomorphological features of NIFTP

Follicular variant of papillary thyroid carcinoma (FVPTC), including encapsulated (E-FVPTC) and infiltrative (I-FVPTC) forms, account for approximately 30% of all PTC. These subtypes demonstrate different biological behavior and molecular profiles when compared to classical PTC. E-FVPTC has low regional recurrence and metastatic potential with a biological behavior similar to that of follicular adenoma. In 2015, a multidisciplinary panel of experts revised the diagnostic terminology for cases of noninvasive E-FVPTC to noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). NIFTP was morphologically defined as a noninvasive follicular patterned neoplasm with nuclear features of PTC and scant nuclear pseudo-inclusions, specifically excluding papillary structures and psammoma bodies. The employment of NIFTP diagnostically has significantly impacted fine needle aspiration (FNA) diagnosis and the associated risk of malignancy employed in reporting thyroid FNA specimens. The emerging literature suggests specific cytomorphologic features more frequently encountered with NIFTP compared to cases of I-FVPTC. This article reviews the cytology literature regarding NIFTP and discusses the significance of this new entity in the practice of thyroid cytopathology.     

Papillary thyroid carcinoma with aggressive fused follicular and solid growth pattern: A unique histological subtype with high-grade malignancy?

Papillary thyroid carcinoma (PTC) is usually indolent; however, some rare subtypes of PTCs, such as columnar cell and hobnail subtypes, carry poor prognosis as an intermediate malignancy between differentiated carcinoma and anaplastic carcinoma. We present the case of a 56-year-old Japanese woman having PTC with aggressive behavior showing characteristic histological features of a predominantly fused follicular and focally solid (FFS) pattern. The fused follicular pattern is cribriform-like without intermingled vessels. This PTC with FFS pattern included frequent mitotic figures, necrosis, lymphovascular invasion, and metastases with high clinical stage. The tumor cells were broadly positive for antibodies to TTF-1, PAX8, and bcl-2, and negative for cyclin D1. Ki-67 labeling index was approximately 10%, and there was occasional positivity of p53. Targeted next generation sequencing analysis only detected a NRAS mutation (Q61K); there was no mutation and no translocation of other genes including BRAF and RET/PTC. To our knowledge, this is first report that PTC shows aggressive FFS growth pattern. The tumor is possibly included in the new category of differentiated high-grade thyroid carcinoma in the World Health Organization 2022 classification, or in a novel subtype of PTC owing to its characteristic histological feature and intermediate malignancy between differentiated carcinoma and anaplastic carcinoma.     

Anaplastic Thyroid Cancer: Ultrasonographic Findings and the Role of Ultrasonography-Guided Fine Needle Aspiration Biopsy

Purpose

To investigate the ultrasonographic (US) features of anaplastic thyroid cancer (ATC) and the diagnostic performance of US-guided fine needle aspiration biopsy (FNAB) therein.

Materials and Methods

Eighteen cases of ATC diagnosed between January 2001 and May 2011 were included. FNAB was performed in all cases. Initial FNAB results were divided into three groups: 1) the cytological ATC group, cytological diagnosis of ATC; 2) the underestimated group, cytological diagnoses of malignancy other than ATC; and 3) the false negative group, cytological diagnoses of atypical, benign and non-diagnostic lesions. We retrospectively reviewed US findings and compared treatment modalities between each group.

Results

Among the 18 patients, there were nine in the initially cytological ATC group, four in the underestimated group and five in the false negative group. The most common US features of ATC were a solid (64.7%) and irregular shaped (88.2%) mass with lymph node involvement (76.4%). However, except for lymph node involvement (p=0.003), US findings for each group were not statistically different. The initial cytological diagnostic accuracy of ATC was 50% (9/18). Surgery was performed less in the ATC group (11%) and the false negative group (20%) than the underestimated group (75%).

Conclusion

The US features of ATC were not especially different from other types of aggressive thyroid cancer. A correct diagnosis of ATC by initial US-FNAB was made in 50% of the patients, which is significant in that therapeutic surgery can be undertaken in lower numbers if correctly diagnosed.     

Metastatic bronchioloalveolar carcinoma presenting as a solitary thyroid nodule: report of a case with fine-needle aspiration cytopathology

Although cancers metastatic to the thyroid are frequently mentioned in autopsy studies, such a finding is quite rare in routine clinical practice. Metastatic non-small-cell carcinomas to the thyroid may present a diagnostic dilemma, particularly when they share morphological similarities with primary thyroid tumors. Herein, we report a case of metastatic bronchioloalveolar carcinoma that presented as an isolated left thyroid nodule in a 68-year-old woman. The aspirates were cellular and showed numerous papillary-like tissue fragments, elongated nuclei with prominent nuclear grooves, frequent mitoses, and psammoma bodies. The latter features raised the possibility of papillary thyroid carcinoma. However, also seen were three-dimensional tumor nests and acinar-forming fragments. Immunostains (positive for cytokeratin-7 and carcinoembryonic antigen and negative for cytokeratin-20 and thyroglobulin) confirmed the metastatic nature of the carcinoma. In a patient with known primary neoplasm, the differential diagnosis of a thyroid nodule should always include a metastatic lesion along with primary neoplasia.     

Dual malignancy in a thyroid; papillary thyroid carcinoma and small lymphocytic lymphoma; a report of a case with a cyto‐histologic correlation

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Simultaneous involvement of the thyroid gland by multiple malignancies, is a rare occurrence. Similarly, primary thyroid lymphomas are also rare. We are reporting a rare case of a dual thyroid malignancy; PTC with secondary thyroid involvement by chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diagnosed on cytology and confirmed with flow cytometry, histology and immunohistochemistry. Imaging showed two hypermetabolic nodules, one in left parotid gland, and the other in the thyroid isthmus. Cytology smears showed features of PTC along with an atypical lymphocytic infiltrate, which co‐expressed CD5, CD19, and CD23 on flowcytometry analysis. Subsequent thyroidectomy showed the atypical lymphocytic infiltrate involving the PTC papillae themselves. The diagnosis of dual malignancies on thyroid FNA is extremely rare and often unexpected, but is possible using appropriate ancillary studies.     

Metronomic Chemotherapy in Anaplastic Thyroid Carcinoma: A Potentially Feasible Alternative to Therapeutic Nihilism

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies and prognostic outlook remains very dismal. Treatment most often is palliative in intent attempting to relieve the patients from local compressive symptoms in the neck. Radical surgery, radiotherapy (RT), and chemotherapy have not been tested in large prospective trials, and current evidence from retrospective series and small trials indicate only marginal survival benefits. Given the poor prognostic and therapeutic outlook, patients must be encouraged to be actively involved in the decision making process. We report the case of an elderly patient who had no response to palliative RT, and was treated with oral metronomic chemotherapy. The response to oral metronomic chemotherapy was dramatic, and the patient has enjoyed complete freedom from symptoms as well as radiologically exhibits a complete regression. Thus, we document the first ever use of a simple, cost-effective, and convenient oral metronomic chemotherapeutic regimen delivering a remarkable response in an elderly patient with ATC.