Columnar cell carcinoma of the thyroid

A case of columnar cell carcinoma of the thyroid occurring in a 50-yearoid female is described. Histologically, the 2 cm tumor showed a prominent papillary architecture with thin fibrous cores covered by columnar cells and marked nuclear stratiflcation. It also showed microfollicular, glandular, and solid pattems. The nuclear features were different to those of conventional papillary carcinomas and similar to those of follicular tumors. The tumor was principally encapsulated with vascular and minimal capsular invaslon. The tumor cells were positive for thymglobulin. The tumor was DNA diploid with a low S phase fraction as determined by flow cytometry. The patient had no lymph node or distant metastasis. The patient was well and without disease 9 months after surgery. The possibility that the neoplasm is one of poorly differentiated thyroid carcinomas rises.     

Coexistence of primary squamous cell carcinoma of thyroid with classic papillary thyroid carcinoma

Primary squamous cell carcinoma of the thyroid gland is very rare and its histogenesis is poorly defined so far. Although there have been some cases of squamous cell carcinoma with variant types of papillary thyroid carcinoma (PTC), the present case is the first primary squamous cell carcinoma with classic PTC to be reported. A 43‐year‐old woman presented with a 20 year history of neck mass. Neck ultrasound indicated a 6 × 4 × 3 cm large mass. The patient underwent total thyroidectomy. Histopathology indicated a well‐differentiated squamous cell carcinoma and squamous metaplasia in conjunction with classic PTC. On immunohistochemistry cytokeratin 7 was positive in papillary carcinoma and squamous metaplasia, thyroglobulin was positive only in papillary carcinoma, and p63 was positive in squamous metaplasia and squamous cell carcinoma. Postoperatively, the patient received 59.4 Gy adjuvant radiotherapy, hormonal therapy and radioactive iodine therapy. At 8 months after surgery the patient remained disease free.     

Intraepithelial Neutrophils in Thyroid Fine-Needle Aspiration: A Portent of Aggressive Thyroid Cancer?

We report three patients with papillary thyroid carcinoma in whom fine-needle aspiration (FNA) showed neutrophils within tumor cells. All three patients presented with large neck masses; at excision, two proved to be tall cell variants of papillary cancer. Nodal metastasis, extrathyroidal extension, and vascular invasion were found in both cases. One patient has experienced recurrent disease; the other has an increasing thyroglobulin titer but no clinically appreciable recurrence. The third patient refused further therapy, but brain metastases were noted clinically; this patient died of disease. In each case, FNA showed tumor clusters with characteristic nuclear features, papillary groups, and psammoma bodies. Neutrophils were present in the cytoplasm of tumor cells in the absence of necrosis. Immunostaining for proliferating cell nuclear antigen (PCNA), MIB-1 (Ki-67), and p53 tumor suppressor gene product was markedly positive. Intraepithelial neutrophils have not been previously reported in differentiated thyroid tumors. We postulate that these neoplasms produce specific leukocyte-attracting cytokines analogous to those produced by anaplastic and poorly differentiated thyroid carcinomas. We believe the finding of intraepithelial leukocytes in the absence of necrosis in thyroid FNA specimens represents a characteristic of clinically aggressive differentiated papillary neoplasms; in our small series, each represented a tall cell variant of papillary carcinoma.     

Columnar Cell Carcinoma of the Thyroid: MIB-1 Immunoreactivity as a Prognostic Factor

We report a case of columnar cell carcinoma of the thyroid. A 47-year-old Japanese man had a nonencapsulated thyroid mass that infiltrated the surrounding tissues extensively. Seventeen months after thyroidectomy he died of respiratory failure resulting from tracheal invasion. An autopsy showed distant metastases to the liver, lung, esophagus, and pancreas. Histologically, the thyroid mass consisted of tall columnar atypical cells with marked nuclear stratification. About one-fifth of tumor cells were immunopositive for MIB-1. The MIB-1 positive index of our case was extremely high, compared with that of ordinary papillary carcinoma. This case indicates that biological growth activity in columnar cell carcinoma may be similar to that of undiferentiated carcinoma of the thyroid, since the MIB-1-positive index is close to each other.     

Follicular variant of papillary carcinoma: cytologic findings on FNAB samples-experience with 16 cases

Between January 1, 1992 and December 31, 1997, a cytopathological diagnosis of follicular variant of papillary thyroid carcinoma (FVPC) was made on a series of 16 out of 18 patients with palpable nodules who underwent fine-needle aspiration biopsy (FNAB) in our Department. The results of aspiration biopsy were followed by histopathological examination of the surgically excised tissues. There were three false-negative aspirations (16.6%), of which two were probably bound to fine-needle sampling and one due to a mixture of benign and malignant cells which had originally gone unrecognized. The accuracy of the cytopathologic diagnosis in this variant was 88.8%. An analysis of the diagnostic cytopathological criteria was performed, which demonstrated the importance of both architectural features (monolayered and branching sheets, microacinar structures, and their combinations) and nuclear features (presence of nuclear grooves). Background -bound features were mainly represented by dense, nonfilamentous colloid. The cytopathologic findings in FVPC were compared to those found in a series of 10 usual papillary carcinomas (UPC) and 10 follicular neoplasms (FN). These latter had originally been diagnosed by FNAB and were subsequently classified histologically as follicular adenoma (n = 6), follicular carcinoma (n = 3), or adenomatoid colloid nodule (n = 1). Statistical evaluation was performed on the cytopathological findings in the three classes of lesions (FVPC, UPC, and FN) as to their presence and relative frequency or absence by using a nonparametric one-way ANOVA (Kruskall-Wallis) and, where necessary, a Mann-Whitney U test. Papillary cellular fragments and multinucleated giant cells (P < 0.005), nonfilamentous dense colloid, squamoid cells, and syncytia were significantly more represented in UPC than in FVPC (P < 0.05), while histiocytes were significantly more frequent in FVPC (P < 0.005). Other nuclear and/or background features were significant only in the distinction between papillary carcinomas as a group and FN. The cytological differential diagnosis of the FVPC is briefly discussed with relevance to the possible pitfalls caused by its peculiar cyto- and histomorphology.     

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.     

Distinguishing tall cell variant of papillary thyroid carcinoma from usual variant of papillary thyroid carcinoma in cytologic specimens

Tall cell variant (TCV) is an aggressive form of papillary thyroid carcinoma (PTC), usually associated with higher local recurrence and distant metastasis. Some authors have suggested that TCV can be effectively diagnosed on thyroid fine-needle aspiration (FNA); this diagnosis may help clinicians plan a more effective treatment regimen. The objective of this study was to compare the FNA specimens of TCV with those of usual variant of PTC (UV-PTC) and to define a set of distinguishing cytologic features. Thirty FNA specimens of histologically proven TCV were compared with 32 FNA specimens of histologically proven UV-PTC. All specimens were evaluated for the following features: papillary groups (PG), elongated/tall cells (EL/TC), oncocytic cytoplasm (OC), distinct cell borders (DCB), prominent central nucleoli (PCN), intranuclear grooves (NG), and intranuclear inclusions (NI). These features were semiquantitatively measured on a sliding scale of 0-4 in both air-dried Diff-Quik-stained and ethanol-fixed Papanicolaou-stained preparations. TCV showed distinctive cytologic features, which can distinguish them from UV-PTC. These included EL/TC, OC, and DCB and were also found to be statistically significant (P < 0.0001). No significant differences were noted for PG and NG. The NIs in TCV cases were qualitatively different than those in UV-PTC. In TCV there were multiple inclusions within the same nucleus imparting a "soap bubble appearance" to the nucleus. This feature was seen in almost all cases of TCV and was rarely seen in usual PTC. On the basis of the above-mentioned cytologic features, TCV can be distinguished from usual PTC in FNA specimens.     

RET Proto-Oncogene and Thyroid Cancer

TheRET proto-oncogene has not only conclusively been identified as responsible for the three subtypes of the inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN-2) but also shown to be involved in the molecular evolution of sporadic medullary and papillary thyroid carcinoma as well as Hirschsprung’s disease. A variety of recent studies have elucidated the pathophysiological mechanisms leading to neoplastic disease and we now understand that dominant activating germline mutations lead to MEN-2A, MEN-2B, and familial MTC; somatic mutations to sporadic medullary thyroid carcinoma;RET rearrangements to papillary thyroid carcinoma; and inactivating alterations to Hirschsprung's disease. The clinical significance, however, ofRET alterations especially in sporadic thyroid tumors is still controversial and therapeutic concepts in MEN-2 gene carriers only start to emerge. This article is a short summary of the recent findings on the structure and physiology of theRET proto-oncogene and its role in familial and sporadic thyroid cancer. This article was presented in part at the Endocrine Pathology Society Companion Meeting of the USCAP in Orlando, FL, March 1, 1997.     

The triage efficacy of fine needle aspiration biopsy for follicular variant of papillary thyroid carcinoma using the Bethesda reporting guidelines

Diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) by ultrasound-guided fine-needle aspiration (FNA) is challenging. In this retrospective review, we evaluated triage efficacy (i.e., potential for triggering surgical intervention) in 44 archived FNA biopsies of surgically confirmed FVPTC obtained between December 2006 and December 2008. We compared the original FNA diagnoses with reclassified diagnoses based on 2007 National Cancer Institute (NCI)/Bethesda recommendations, and reviewed FNA cytologic features. Original FNA diagnoses included colloid nodule (7%, 3/44), atypical follicular cells (5%, 2/44), follicular lesion (11%, 5/44), follicular neoplasm (16%, 7/44), suspicious for malignancy/PTC (27%, 12/44), and papillary thyroid carcinoma (34%, 15/44). Reclassified diagnoses included indeterminate (5%, 2/44), colloid nodule (7%, 3/44), atypical cells of undetermined significance [ACUS] (7%, 3/44), Hurthle cell neoplasm (2%, 1/44), follicular neoplasm (7%, 3/44), suspicious for malignancy/PTC (25%, 11/44), and PTC (48%, 21/44). Triage efficacy was 77% (34/44) for original diagnoses versus 82% (36/44) for reclassified FNA diagnoses. We frequently observed cytologic features of PTC, such as nuclear grooves and fine chromatin; conversely, intranuclear inclusions, though present in 77% cases, were scant. Our review findings suggest that lack of characteristic cytologic features of PTC,coexistence with other thyroid lesions, and small tumor size arethe major obstacles to FNA diagnosis of FVPTC. Reclassification of thyroid FNA diagnoses does not significantly improve triage efficacy. Furthermore, FNA diagnoses of follicular neoplasm and suspicious for malignancy are valuable in patients with FVPTC because they trigger triage toward surgical intervention.     

Patterns of papillary thyroid carcinoma cells analyzed in fine-needle aspiration smears may reveal changes in tumor cell behavior

Fine-needle aspiration (FNA) cytology is widely used to examine thyroid lesions. However, its diagnostic accuracy is limited by the narrow choice of cytopathologic markers indicative of invasive/metastatic powers of a tumor. The aim of this study was to identify features that may serve as such indicators. We have examined FNA smears of 50 histologically proven papillary thyroid carcinoma (PTC) cases applying computer-assisted morphometry to assess patterns formed by PTC cells. Cytokeratine (CK) 8 immunocytochemistry was used to verify the epithelial origin of cells under study. All analyzed smears contained blood, histiocyte-like cells and CK8-positive follicular cells occurring both as single cells and in monolayer cell sheets. In 60% of cases we revealed cell sheets displaying two distinct cell patterns. The first one (pattern R) consisted of moderately pleomorphic, rather regularly arranged cells having an amphophilic cytoplasm. The second one (pattern I) was formed by highly pleomorphic cells with a basophilic cytoplasm. Patterns R and I were clearly different in cell size and shape as well as in nuclear size and shape. These patterns were never observed within the same cell sheet indicating that they may be formed by different subclones of tumor cells. Thus, it can be concluded that PTC frequently displays two definitely different cell patterns. We think that these patterns have a potential to serve as indicators for early events of an invasive/metastatic process. It remains to be seen whether the simultaneous occurrence of these patterns is a PTC-specific feature.     

Detection of ectopic thyroid remnants: A serious diagnostic dilemma. When molecular biology and immunohistochemistry can solve the problem

The presence of ectopic thyroid tissue is a frequent diagnostic feedback related to a possible histogenetic abnormality or a result of post-surgical seeding. The important challenge is the diagnostic definition of its nature, which could lead to a different therapeutic approach. We describe a case with all the possible implications and differential diagnoses supported by the application of immunohistochemistry and BRAF-V600E molecular detection.     

Fine-needle aspiration cytology of papillary Hürthle cell carcinoma with lymphocytic stroma “Warthin-like tumor” of the thyroid

Papillary Hürthle cell carcinoma with lymphocytic stroma is a recent addition to the list of variants of papillary carcinoma of the thyroid. We report the aspiration cytology and histology findings of this tumor arising in two patients. The smears were cellular, and revealed Hürthle cells arranged in three-dimensional groups, papillary fragments, and as singly dispersed cells with a prominent intimately associated inflammatory component of lymphocytes and few plasma cells. The Hürthle cells were pleomorphic and showed granular eosinophilic cytoplasm, eccentrically oriented nuclei with prominent nucleoli. Nuclear features of papillary carcinoma were present among both the cellular groups and scattered cells. The histologic examination showed a circumscribed papillary tumor comprising Hürthle cells and a brisk inflammatory component filling the stalks of papillae. These findings were consistent with a papillary Hürthle cells carcinoma with lymphocytic stroma, the so-called Warthin-like tumor of the thyroid. Hürthle cells admixed with inflammatory cells in cytology preparations can be seen in Hürthle cell nodules or neoplasms arising in a background of chronic lymphocytic thyroiditis. We suggest that a careful search for nuclear features may be helpful in diagnosing this variant of papillary carcinoma.