bromochloroacetic-acid and Thyroid-Nodule

Primary spindle cell neoplasms of the thyroid gland are quite rare. They encompass a heterogeneous group of benign and malignant lesions of mesenchymal and epithelial origin. We herein describe two unusual follicular thyroid adenomas dominated by spindle cells with occasional areas of colloid-forming follicular differentiation. The tumors affected a 77-year woman and a 70-year old man; both had a long-history of monoclonal gammopathy of unknown significance (MGUS). One tumor presented as a large cold thyroid nodule and the other was an autopsy finding. The tumors were predominantly composed of fibroblast-like spindled cells. One case showed prominent meningioma-like concentric perivascular arrangement and contained cytoplasmic melanin-like pigment. Stromal hyalinization was a prominent feature of both. By immunohistochemistry, the spindled cells expressed vimentin, pankeratin (KL1), thyroglobulin and TTF1 consistent with a follicular differentiation. They did not stain with calcitonin, CEA and other lineage-specific mesenchymal, neuroendocrine and melanocytic markers. There was no evidence of metastasis at autopsy (case 2) or at last follow-up 2 years after surgery (case 1). These cases demonstrate the diversity of follicular thyroid neoplasms and the unusual occurrence of extensive spindle cell metaplasia. These uncommon lesions need to be distinguished from spindle cell medullary carcinoma, paucicellular spindle cell anaplastic carcinoma, spindle cell foci in papillary and follicular carcinoma, solitary fibrous tumor and other rare benign and malignant mesenchymal lesions.

Topics: Adenoma; Aged; Biomarkers, Tumor; DNA-Binding Proteins; Fatal Outcome; Female; Humans; Keratins; Male; Monoclonal Gammopathy of Undetermined Significance; Thyroglobulin; Thyroid Neoplasms; Thyroid Nodule; Thyroidectomy; Transcription Factors; Vimentin

Clinically evident metastases of carcinomas to the thyroid gland are rare, particularly from a colorectal primary tumor. We present a case of colonic adenocarcinoma metastatic to the thyroid gland with histopathologic and immunohistochemical findings. A 68-year-old woman with a history of Dukes' stage B colon carcinoma presented a mass in the thyroid gland. The tumor was confirmed to be metastatic adenocarcinoma from the colon. The immunohistochemical findings demonstrated positive staining for cytokeratin 20, low-molecular-weight cytokeratin, villin and carcinoembryonic antigen, but stains were negative for cytokeratin 7 and thyroglobulin.

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Carcinoembryonic Antigen; Carrier Proteins; Colonic Neoplasms; Female; Humans; Immunoenzyme Techniques; Intermediate Filament Proteins; Keratin-20; Keratin-7; Keratins; Microfilament Proteins; Thyroid Neoplasms; Thyroid Nodule; Tomography, X-Ray Computed

Core needle biopsy (CNB) has been recently described as an accurate second-line test in thyroid inconclusive cytology (FNA). Here we retrospectively investigated the potential improvement given by Galectin-3, Cytokeratin-19, and HBME-1 on the accuracy of CNB in thyroid nodules with prior indeterminate FNA report. The study included 74 nodules. At CNB diagnosis, 15 were cancers, 40 were benign, and 19 had uncertain/non-diagnostic CNB report. The above immunohistochemical (IHC) panel was analyzed in all cases. After surgery, 19 malignant and 55 benign lesions were found. All 15 cancers and all 40 benign nodules diagnosed at CNB were confirmed at final histology. Regarding the uncertain CNB group, 4 (21 %) were malignant and 15 (79 %) benign. When we considered all the series, the most accurate IHC combination was Galectin-3 plus HBME-1, while HBME-1 was the most sensitive marker in those nodules with uncertain CNB report. The combination of CNB plus IHC could indentify 19/19 cancers and 53/55 benign lesions. Sensitivity and specificity of CNB increased from 79 to 100 % and from 73 to 96 %, respectively, by adding IHC. CNB can diagnose the majority of thyroid nodules with previous indeterminate FNA cytology, while the accuracy of CNB is increased by adding Galectin-3, Cytokeratin-19, and HBME-1 panel. We suggest to adopt CNB as a second-line approach to indeterminate thyroid FNA, and apply IHC in those lesions with uncertain/non-diagnostic CNB report. This approach should improve the pre-surgical diagnosis of patients. These results should be confirmed in larger prospective series.

Topics: Adult; Aged; Biomarkers; Biomarkers, Tumor; Biopsy, Large-Core Needle; Female; Galectin 3; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Prospective Studies; Reproducibility of Results; Thyroid Neoplasms; Thyroid Nodule

Thyroid paragangliomas are extremely rare tumors arising from the inferior laryngeal paraganglia. Most patients are female and present as asymptomatic thyroid nodule. Diagnosing thyroid paraganglioma can be difficult on fine-needle aspiration (FNA) since it could be misdiagnosed as medullary thyroid carcinoma, calcitonin-negative neuroendocrine tumor of the thyroid gland (CNNETT), metastatic neuroendocrine tumor, and intrathyroid parathyroid proliferation. We describe the cytologic features and immunohistochemical staining pattern of thyroid paraganglioma from a 60-year-old woman with a gradually enlarging neck mass for several months. An ultrasound guided fine-needle aspiration was performed which revealed epithelioid, plasmacytoid to occasionally spindle-shaped cells with ovoid to elongated nuclei, fine chromatin pattern and inconspicuous nucleoli. The cells were arranged singly, in sheets, and focally in acinar pattern. Occasional nuclear overlapping, crush artifact, and binucleated cells were identified. Neither colloid nor amyloid was seen. Immunohistochemical stains performed on the cell block showed the tumor cells were positive for neuroendocrine markers and negative for cytokeratin (AE1/AE3), calcitonin, CEA, thyroglobulin, and TTF-1. There were rare S-100 positive cells. Given the difference in management of paragangliomas compared to its cytology mimics and association with familial cancer syndromes in some cases, awareness of this rare tumor, and use of immunohistochemical stains are critical in arriving at the diagnosis.

Topics: Biomarkers, Tumor; Biopsy, Fine-Needle; Calcitonin; Carcinoembryonic Antigen; Cytodiagnosis; Female; Humans; Immunohistochemistry; Keratins; Middle Aged; Nuclear Proteins; Paraganglioma; Thyroglobulin; Thyroid Gland; Thyroid Neoplasms; Thyroid Nodule; Thyroid Nuclear Factor 1; Transcription Factors

The searching of the reliable and repeatable immunohistochemical markers in the differential diagnosis of the thyroid's differentiated follicular epithelial neoplasms has been continuing. Recently, the studies have majored on immunohistochemical markers such as high-molecular weight cytokeratin (HMW-CK), galectin-3, cytokeratin 19, and p27. We aimed to evaluate the differences of the expressions of the proliferating cell nuclear antigen (PCNA), thyroid transcription factor-1 (TTF-1), Ki-67, p63, p53, and HMW-CK among the papillary thyroid carcinomas (PTCs), follicular carcinomas (FCs), and follicular adenomas (FAs). Thirty-nine patients with the diagnoses of the PTC, FC, and FA in the archives of the Izmir Tepecik Training and Research Hospital Pathology Laboratory registries in between 2004 and 2009 were included in the study. Immunohistochemical stains for PCNA, TTF-1, Ki-67, p63, p53, and HMW-CK were applied. The results were analyzed statistically by using Statistical Package for the Social Sciences (SPSS) for Windows 16.0 program (SPSS Inc., IBM, Somers, New York, USA). In all 3 groups, all tumors showed PCNA and TTF-1 positivity. Ki-67 proliferation index varied in a wide range in all groups. Although it was not statistically significant, 19 of 39 tumors (7 PTCs, 2 FCs, and 10 FAs) were stained with p63. The results of the immunoreactivity seen in PTCs with p53 (41.2%) and HMW-CK (52.9%) were statistically significant. The tumors in the other 2 groups (FC and FA) showed no reactivity with HMW-CK. Although the differential diagnosis of the thyroid follicular neoplasms are based on the histologic and cytomorphological criteria, p53 and HMW-CK positivity might be undertaken in favor of the diagnosis of the PTC.

Topics: Adenoma; Adolescent; Adult; Age Distribution; Aged; Biomarkers, Tumor; Carcinoma; Carcinoma, Papillary; Child; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Keratins; Ki-67 Antigen; Male; Membrane Proteins; Middle Aged; Molecular Weight; Nuclear Proteins; Proliferating Cell Nuclear Antigen; Sex Distribution; Thyroid Cancer, Papillary; Thyroid Neoplasms; Thyroid Nodule; Thyroid Nuclear Factor 1; Transcription Factors; Tumor Suppressor Protein p53; Young Adult

Classification of necrotic or degenerate thyroid nodules can be difficult. The aim of this study was to investigate the value of cytokeratins, thyroid-specific markers (TTF-1 and thyroglobulin) and HBME-1 antibodies in such thyroid lesions.. Twenty-eight necrotic or degenerate thyroid lesions, including four cervical cystic papillary carcinoma (CPC) metastases, were evaluated with immunohistochemistry for TTF-1, thyroglobulin, HBME-1, AE1&3, Cam5.2, MNF116 and cytokeratin (CK)19. There was loss of TTF-1 staining in all necrotic lesions, with positive staining in degenerate tumour cells of all four metastatic CPCs. Thyroglobulin was retained in 18 lesions. Dual CK19 and HBME-1 expression was seen only in six of seven necrotic papillary thyroid carcinomas and the four metastatic CPCs. Retained immunoreactivity for AE1&3 and Cam5.2 was seen in most necrotic papillary carcinomas (n = 11/11 and n = 10/11, respectively), poorly differentiated carcinomas (n = 2/3 and n = 3/3, respectively) and follicular-patterned areas of anaplastic carcinoma (n = 3/5 and n = 4/5, respectively). Cam5.2 showed spurious staining of macrophages in eight lesions.. Thyroglobulin is useful in establishing the thyroid origin of a necrotic lesion. TTF-1 may be useful for highlighting degenerate tumour cells within metastatic CPCs. Retained expression of CK19 and HBME-1 is seen in necrotic papillary carcinomas. AE1&3 is the most specific and Cam5.2 the most sensitive of the CK cocktails in non-viable thyroid lesions.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Necrosis; Thyroglobulin; Thyroid Nodule; Young Adult

To study Twist expression in thyroid papillary carcinoma (PTC) by immunohistochemistry and to assess its usefulness as marker in the differential diagnosis of PTC, follicular adenomas (FA) and benign papillary lesions (BPL).. Fifty cases of PTC, 48 cases of FA and 47 cases of BPL were evaluated using manual tissue chip and SP immunohistochemical stain to detect the expression of Twist and HBME-1, and comparing the staining to that of cytokeratin 19 (CK19).. In PTC, positive rates of Twist, HBME-1 and CK19 were 100% (48/48), 94.0% (47/50) and 78.0% (39/ 50) respectively; in FA, positive rates were 0, 6.7% (3/45) and 0 respectively; in BPL, positive rates were 7.0% (3/34), 2.1% (1/47) and 0, respectively. The differences between PTC and FA and between PTC and BPL were both statistically significant (P = 0. 000). The sensitivity of Twist, HBME-1 and CK19 was 100%, 94.0% and 78.0%; the specifity was 96.4%, 95.7% and 100%; overall accurary was 97.7%, 95.1% and 91.9%, respectively.. Positive rates of Twist is higher than the other markers in PTC. Immunohistochemical staining of Twist has important significance in the differential diagnosis of thyroid lesions. Twist immunohistochemistry maybe helpful in diagnosis and differential diagnosis of PTC.

Topics: Adenocarcinoma, Follicular; Adenocarcinoma, Papillary; Adenoma; Biomarkers, Tumor; Carcinoma, Papillary; Carcinoma, Papillary, Follicular; Diagnosis, Differential; Galectin 3; Immunohistochemistry; Keratin-19; Keratins; Nuclear Proteins; Thyroid Neoplasms; Thyroid Nodule; Twist-Related Protein 1

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27(kip1) in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC). The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC.

Topics: Adenocarcinoma, Follicular; Biomarkers, Tumor; Carcinoma, Papillary, Follicular; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Diagnosis, Differential; Galectin 3; Humans; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Keratin-19; Keratins; Sensitivity and Specificity; Thyroid Gland; Thyroid Nodule

Fine-needle aspiration (FNA) specimens from thyroid nodules arising in Graves' disease (GD) can pose diagnostic difficulties because the cytomorphologic changes in GD may mimic nuclear features of papillary thyroid carcinoma (PTC). In addition, treatment of GD patients with radioactive iodine (RAI) may cause significant cytologic atypia, further increasing the diagnostic difficulty. From March 1999 to April 2002, a total of 14 hypofunctioning nodules in 9 patients with GD underwent FNA; 3 patients had received RAI treatment. Three cases were diagnosed as suspicious for PTC and 11 as benign. Three patients with the diagnosis of suspicious for PTC on FNA underwent surgery and were found to have papillary carcinoma. We assessed all cases to find key cytologic features that can differentiate between nodules with reactive/reparative nuclear atypia from PTC arising in GD. The cytologic features assessed included cellularity, amount of colloid, monotony of the cell population, oncocytic features, cell crowding, lymphocytic infiltration, nuclear elongation, nuclear grooves, pale powdery chromatin, presence of small eccentric nucleoli, and random nuclear atypia. Each feature was semiquantitatively graded on a sliding scale of 0 to 4, with 0 representing absence and 4 representing a predominance of the feature. The mean value of each feature was calculated and the benign and malignant lesions were compared using the unpaired t-test. Four features were found to be statistically significant in the diagnosis of PTC as compared to the benign nodules in GD. The nuclei of PTC in GD show prominent nuclear elongation, pale powdery chromatin, intranuclear grooves, and small eccentric nucleoli. All other features studied were not found to be statistically significant. There does exist an overlap between the cytologic features of benign nodules and PTC arising in GD. However, adherence to strict diagnostic criteria (nuclear elongation, pale powdery chromatin, intranuclear grooves, and small eccentric nucleoli) can enable the diagnosis of PTC arising in GD.

Topics: Adult; Aged; Biomarkers, Tumor; Biopsy, Fine-Needle; Carcinoma, Papillary; Diagnosis, Differential; Female; Graves Disease; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Retrospective Studies; Thyroid Neoplasms; Thyroid Nodule

To study immunohistochemical expression of cytokeratin19 (CK19), galectin-3 (Gal-3) and HBME-1 in thyroid lesions and to assess their usefulness as markers in the differential diagnoses of thyroid nodular lesions.. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissue of 21 cases of nodular goiters, 14 cases of toxic goiters, 15 cases of follicular adenomas (FA), 13 cases of follicular carcinomas (FC), 13 cases of follicular variant papillary carcinomas (FVPC) and 48 cases of classic papillary carcinomas (CPC).. All three markers were expressed in the cytoplasm with no or weak expression in benign lesions and diffuse and strong in malignant cases. Positive expressions of CK19, Gal-3 and HBME-1 were present in 11of 21, two of 21, four of 21 in nodular goiters, seven of 14, one of 14, one of 14 in toxic goiters, nine of 15, two of 15, two of 15 in FA, 10 of 13, eight of 13, seven of 13 in FC, 13 of 13, 11 of 13, 12 of 13 in FVPC, and 48 of 48, 45 of 48, 46 of 48 in CPC. The expression rates of the three markers between benign lesions (nodular goiters, toxic goiters and FA) and malignant lesions (FA, FVPC and CPC) were statistically significant. Among the three follicular lesions (FA, FC and FVPC), the differences were statistically significant as well. Nine, seven and six cases were negative for all three markers in nodular goiters, toxic goiters and FA, respectively. Only one case in FC was negative for all three markers, no case was all negative in FVPC and CPC; the rate of one case with two or more positive marker expression in nodular goiters, toxic goiters, FA, FC, FVPC and PC was 14.2% (3/21), 21.43% (3/14), 20.0% (3/15), 69.2% (9/13), 92.3% (12/13), 100.0% (48/48), the differences between benign lesions and malignant lesions and between FA, FC and FVPC were also statistically significant.. Immunohistochemical stains of CK19, Gal-3 and HBME-1, especially when used in combination, can be an important adjunct to the histopathological diagnoses of thyroid lesions.

Topics: Adenocarcinoma, Follicular; Adenoma; Biomarkers, Tumor; Carcinoma, Papillary, Follicular; Diagnosis, Differential; Galectin 3; Goiter, Nodular; Humans; Immunohistochemistry; Keratins; Thyroid Neoplasms; Thyroid Nodule

Immunohistochemical staining for cytokeratin 19 (CK-19) is a useful ancillary technique for diagnosing papillary thyroid carcinoma (papillary carcinoma) in histologic specimens. Although similar results have been obtained on aspirate smears, to our knowledge the utility of CK-19 immunolocalization in cell block preparations as an adjunct to fine-needle aspiration diagnosis of papillary carcinoma has not been examined.. The purpose of this study was to determine whether CK-19 immunostaining of cell block preparations of thyroid aspirates is a useful ancillary technique for diagnosing papillary carcinoma.. Using a monoclonal antibody to CK-19 and a standard avidin-biotin complex technique, immunostaining was performed on paraffin-embedded cell blocks of 57 cases with the following cytologic diagnoses: (a) papillary carcinoma (20 cases); (b) atypical cytology, cannot exclude papillary carcinoma (19 cases); and (c) nonneoplastic thyroid (18 cases). The staining reaction in each case was graded on the basis of percentage of epithelial cells stained (1+, <10%; 2+, <10%-50%; 3+, >50). Tissue follow-up was available in all cases.. Nineteen (95%) of 20 cases with an unequivocal diagnosis of papillary carcinoma were positive for CK-19 (3+). Tissue follow-up confirmed papillary carcinoma in all 20 cases. Of the 19 cases with a diagnosis of atypical cytology, cannot exclude papillary carcinoma, 7 (37%) cases displayed 3+ immunostaining and subsequent excision confirmed papillary carcinoma in all 7 cases. The remaining 12 cases with 1+ immunostaining included surgically confirmed goiter (6 cases), adenoma (2 cases), lymphocytic thyroiditis (3 cases), and papillary carcinoma (1 case). The follicular cells in 18 cases with a cytologic diagnosis of nonneoplastic thyroid showed 1+ immunostaining. Histologic follow-up of these cases confirmed the nonneoplastic cytologic diagnoses.. Cytokeratin 19 immunostaining of cell block preparations of thyroid aspirates serves as a useful tool for the diagnosis of papillary carcinoma. Strong immunostaining (3+) for CK-19 aids in accurate diagnosis of malignancy in cytomorphologically equivocal cases of papillary carcinoma.

Topics: Biopsy, Needle; Carcinoma, Papillary; Cytodiagnosis; Epithelial Cells; Humans; Immunohistochemistry; Keratins; Paraffin Embedding; Retrospective Studies; Staining and Labeling; Thyroid Neoplasms; Thyroid Nodule; Tissue Fixation

The immunohistochemical expression of cytokeratin 19 (CK 19) and galectin-3 was evaluated in 69 thyroid lesions to assess their potential as markers in the diagnosis and classification of thyroid malignancy. The following were studied: 26 cases of papillary carcinoma, 12 of follicular carcinoma, 20 follicular adenomas, two medullary carcinomas, one anaplastic carcinoma and eight multinodular goitres.. Formalin-fixed paraffin-embedded thyroid tissues were stained immunohistochemically for both CK 19 and galectin-3. CK 19 expression was found in all 26 papillary carcinomas, five of 12 follicular carcinomas, two of two medullary carcinomas and one case of anaplastic carcinoma. Only five of 20 follicular adenomas were positive for CK 19, and this was in a focal distribution. Two of eight multinodular goitres stained focally positive. Galectin-3 expression was found in 22 of 26 papillary carcinomas, 12 of 12 follicular carcinomas and one of two cases of medullary carcinoma. Only two of 20 follicular adenomas were positive. Three of eight multinodular goitres showed focal galectin-3 expression.. Our findings suggest that the immunohistochemical localization of CK 19 and of galectin-3 is a useful adjunct to the histopathological diagnosis of a solitary thyroid lesion. The expression of CK 19 favours a diagnosis of papillary carcinoma in all its variant patterns. Galectin-3 may serve as a marker for the recognition of follicular carcinoma, particularly the minimally invasive form.

Topics: Diagnosis, Differential; Galectin 3; Humans; Immunohistochemistry; Keratins; Retrospective Studies; Thyroid Nodule

Topics: Adenoma; Biomarkers, Tumor; Carcinoma, Papillary; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Pathology; Thyroid Neoplasms; Thyroid Nodule

To evaluate the expression of cytokeratin (CK) 19, we stained sections obtained from formalin-fixed, paraffin tissue blocks of 35 thyroid tumors (follicular adenoma [FA], 20; papillary thyroid carcinoma [PTC], 10 follicular variant [FV] and 5 usual type) and scored the extent of staining as follows: 1+ (<5% positively stained cells), 2+ (5%-25% positively stained cells), 3+ (25%-75% positively stained cells), and 4+ (>75% positively stained cells). All 15 PTCs (including 10 FV-PTCs) were CK19 positive: 14 were 4+ and 1 (FV-PTC) was 2+. All 20 FAs also were CK19 positive: 15 were 1+, 1 was 2+, 4 were 3+, and none was 4+. In the FAs that were scored 1+, reactivity usually was confined to follicular cells lining cystically dilated atrophic follicles that lacked the typical nuclear features of PTC. The remaining FAs showed more diffuse reactivity, which was, however, less intense than that observed in the PTCs. Thus, immunoreactivity for CK19 is not specific for PTC, although we acknowledge that the extent and intensity of staining are considerably greater in this tumor than in FA. There were no significant differences in staining for CK19 between nonneoplastic follicles adjacent to PTCs and those adjacent to FAs.

Topics: Adenoma; Biomarkers, Tumor; Carcinoma, Papillary; Cell Count; Diagnosis, Differential; Humans; Immunoenzyme Techniques; Keratins; Pathology; Thyroid Gland; Thyroid Neoplasms; Thyroid Nodule

Solitary papillary hyperplastic thyroid nodules (SPHTNs) are frequently encountered in children and teenagers. Although the histologic features are well described, to the best of our knowledge, cytologic findings have not been reported.. To review the cytologic features of histologically proven SPHTNs and to identify the potential diagnostic pitfalls in cytologic diagnosis.. Fine-needle aspiration cytology of 3 histologically proven SPHTNs was reviewed.. Two girls and 1 boy (ages 11, 12, and 15 years) were affected. The cytologic diagnosis in all 3 cases was suspicious for papillary thyroid carcinoma (PTC). The spectrum of cytologic findings included broad flat sheets and 3-dimensional clusters with fire flares. There was mild to moderate nuclear pleomorphism and nuclear atypia. Short nonbranching papillae with transgressing vessels shown to represent hyperplastic papillae on histologic sections were identified in all cases. The background contained giant cells, histiocytes, and watery and inspissated colloid. Although nuclear grooves were identified in occasional cells, intranuclear inclusions were absent. A cell block section (1 case) and histologic sections of SPHTNs (2 cases) were immunohistochemically negative for cytokeratin 19.. Fine-needle aspiration of SPHTNs may be difficult to interpret accurately and can result in false-positive diagnosis of PTC. Although it shares several cytologic features with PTC, the presence of fire flares and short nonbranching papillae, as well as lack of intranuclear inclusions and watery and inspissated colloid in SPHTN appear to be useful features that are helpful in distinguishing SPHTN from PTC. Negative immunohistochemical staining for cytokeratin 19 is useful in excluding a diagnosis of PTC.

Topics: Adolescent; Biomarkers, Tumor; Biopsy, Needle; Carcinoma, Papillary; Child; Diagnosis, Differential; Female; Humans; Hyperplasia; Immunoenzyme Techniques; Keratins; Male; Thyroid Nodule