Papillary Thyroid Carcinoma Tall Cell Variant

Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Thyroid: official journal of the American Thyroid Association (Impact Factor: 4.49). 10/2008; 18(11):1179-81. DOI: 10.1089/thy.2008.0164
Source: PubMed

ABSTRACT BACKGROUND: The most common of the aggressive variant of papillary thyroid carcinoma (PTC) is the tall cell variant (TCV). Because there are serious prognostic and management implications to a diagnosis of TCV, we review the entity to inform clinicians about the many facets of TCV. SUMMARY: The TCV of PTC is characterized by cells having the nuclear features of PTC and whose height is at least twice or thrice their width. There is disagreement regarding the proportion of tall cells and the cell height required to diagnose TCV. In view of its blurred definition and rarity, studies have shown that TCV is still underdiagnosed. We propose that PTC be diagnosed as TCV if it is composed of > or =50% tall cells. The latter should have a height that is at least twice their width, an eosinophilic cytoplasm, and the nuclear features of PTC. Whatever its definition, there is a consensus that TCV has a higher recurrence and death rate than classical PTC. Most authorities believe that TCV's worse prognosis is related to its older age at presentation, larger tumor size, and high frequency of extrathyroid extension (ETE). However, in a recent article, TCV without ETE was shown to have a more aggressive behavior than classical PTC without ETE independent of age, gender, and tumor size. The aggressive behavior of TCV could be related to the high expression of Muc1 and matrix metalloproteinase and to the higher prevalence of B-RAF mutations when compared to classical PTC. The importance of TCV is accentuated by the fact that it is overrepresented in those fluorodeoxyglucose positron-emission tomogram (FDG-PET)-positive thyroid carcinomas that are refractory to radioactive iodine (RAI) therapy constituting 20% of these incurable tumors. Conclusion: TCV is a biologically and clinically aggressive form of PTC that is still underdiagnosed. TCV is overrepresented in patients with RAI refractory disease. It has a high prevalence of B-RAF mutations making the latter an attractive target in RAI refractory cases. Imaging modalities that can detect RAI refractory disease such as FDG-PET scanning are needed in many patients and a requirement in those with extensive ETE. More studies are needed to identify those TCV that become RAI refractory and develop effective target therapies against these incurable carcinomas.

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    • "A consensus was reached when there was discrepancy between the observers. We excluded any cases with tumor necrosis or marked mitotic activity (≥3 mitoses/10 high power field, 400×) because these pathologic features themselves could be related to tumor aggressiveness.5,6,19,20 In cases with multiple tumor foci, the largest tumors were selected as the primary lesions. "
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    ABSTRACT: Background The tall cell variant of papillary thyroid carcinoma (TCVPTC) is more aggressive than classic papillary thyroid carcinoma (PTC), but the percentage of tall cells needed to diagnose TCVPTC remains controversial. In addition, little is known about the clinicopathologic features of classic PTC with tall cell features (TCF). Methods We retrospectively selected and reviewed the clinicopathologic features and presence of the BRAF mutation in 203 cases of classic PTC, 149 cases of classic PTC with TCF, and 95 cases of TCVPTCs, which were defined as PTCs having <10%, 10-50%, and ≥50% tall cells, respectively. Results TCVPTCs and classic PTCs with TCF did not vary significantly in clinicopathologic characteristics such as pathologic (p) T stage, extrathyroidal extension, pN stage, lateral lymph node metastasis, or BRAF mutations; however, these features differed significantly in TCVPTCs and classic PTCs with TCF in comparison to classic PTCs. Similar results were obtained in a subanalysis of patients with microcarcinomas (≤1.0 cm in size). Conclusions Classic PTCs with TCF showed a similar BRAF mutation rate and clinicopathologic features to TCVPTCs, but more aggressive characteristics than classic PTCs.
    The Korean Journal of Pathology 06/2014; 48(3):201-8. DOI:10.4132/KoreanJPathol.2014.48.3.201 · 0.17 Impact Factor
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    • "Limited experience exists about the role of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC, including case reports or small case series in patients with tall cell [32], diffuse sclerosing [33] [34] [35], solid/trabecular [36] and insular variant [37] of DTC. These articles underlines that FDG-PET or PET/CT seem to be very useful tools for the staging and restaging of such tumours. "
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    ABSTRACT: Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis.
    International Journal of Endocrinology 04/2013; 2013:856189. DOI:10.1155/2013/856189 · 1.95 Impact Factor
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    • "Although it is controversial whether the histological subtype or variant is an independent predictor of an adverse outcome (1), some histological variants appear to be of prognostic significance. The tall cell variant (TCV), columnar cell, diffuse sclerosing, and solid variants show regional LN metastasis, frequent local recurrence, and even distant metastasis (1, 3-5). LiVolsi argued that the portion showing "tall cell" histologic feature should be mentioned in pathologic reports because of its clinical significance, irrespective of the percentage of this histology (4). "
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    ABSTRACT: Several pathologic characteristics are associated with an adverse clinical outcome in papillary thyroid carcinoma (PTC), including the histological variant. This study aimed to investigate immunohistochemical expression and BRAF mutation status based on the histological variant and evaluated potential markers of aggressive behavior of PTC in Korean patients. In all, 407 PTC cases were classified to each histological variant, and the 94 representative cases were subjected to immunohistochemistry and BRAF mutation analysis. The classic type, follicular variant (FV) and tall cell variant (TCV) represented 76.9%, 14.2% and 6%, respectively. TCV showed a larger tumor size (P = 0.009), frequent extrathyroidal extension (P = 0.022) and cervical lymph node (LN) metastasis (P = 0.018). TCV and FV showed the reduced expression of galectin-3 (P = 0.003) and HBME1 (P = 0.114). Regardless of histology, PTEN loss and diffuse S100A4 expression were associated with LN metastasis (P = 0.007, P = 0.013). All TCVs harbored BRAF V600E mutation, and FV harbored less BRAF V600E mutation (P = 0.043). Immunohistochemical evaluation showed characteristic patterns in histological variants. PTEN and S100A4 expression are suggested as indicators of regional lymph node metastasis.
    Journal of Korean medical science 04/2013; 28(4):534-41. DOI:10.3346/jkms.2013.28.4.534 · 1.27 Impact Factor
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