Fine needle aspiration cytology of follicular variant of papillary carcinoma of thyroid

In this retrospective study, we tried to ascertain the fine needle aspiration cytology (FNAC) features of six histopathologically proven cases of the follicular variant of papillary carcinoma of thyroid (FVPCT). These proven cases were diagnosed from 1998-2000. May-Grunwald-Giemsa and haematoxylin & eosin stained FNAC smears were studied independently by two observers (MP and PD) for detailed cytological features. A comparison of the cytological features was undertaken with those reported in the literature. There were six cases of which only one case was diagnosed as FVPCT while the other five cases were diagnosed as follicular neoplasm (four cases) and neoplasm unclassifiable (one case) on FNAC smears. All these cases showed abundant cellularity with a prominent follicular pattern. No papillae were identified in any of the cases. Syncytial clusters (five cases), nuclear grooves (six cases), nuclear inclusions (one case) and chewing gum colloid (three cases) were noted in variable proportions. We suggest that a differential diagnosis of FVPCT should be considered if the cytology smears show abundant cellularity, syncytial clusters and follicular arrangement along with thick colloid.     

Follicular variant of papillary thyroid carcinoma: diagnostic limitations of fine needle aspiration cytology

OBJECTIVE: To study the diagnostic sensitivity and specificity of fine needle aspiration cytology (FNAC) offollicular variant of papillary thyroid carcinoma (FVPTC). STUDY DESIGN: The study group consisted of 390 papillary thyroid carcinoma (PTC) cases diagnosed histologically with thyroidectomy specimens. The FNAC and histopathologic classification were compared in terms of the appearance of FVPTC and non-FVPTC statistically with the chi squared test. Also, several features of the cytologic smears of FVPTC were reviewed. RESULTS: Twelve of the 390 PTC cases were classified as FVPTC histologically. Five of the 12 cases were also reported as FVPTC in the diagnosis by FNAC and the other 7 as the usual type of PTC (UTPTC). There was 1 case classified as UVPTC histologically but FVPTC cytologically. If we use histologic diagnosis as the gold standard, the sensitivity and specificity of FNAC diagnosis of FVPTC were 42% and 83%, respectively. CONCLUSION: FNAC may be a good tool for diagnosing PTC, but it is unreliable to differentiate between FVPTC and UTPTC.     

Nuclear envelope organization in papillary thyroid carcinoma

Papillary thyroid carcinomas (PTCs) have characteristic nuclear shape changes compared to follicular-type thyroid epithelium. We tested the hypothesis that the altered nuclear shape results from altered distribution or expression of the major structural proteins of the nuclear envelope. Lamin A, lamin B1, lamin C, lamin B receptor (LBR), lamina-associated polypeptide 2 (LAP2), emerin, and nuclear pores were examined. PTC's with typical nuclear features by H&E were compared to non-neoplastic thyroid and follicular neoplasms using confocal microscopy, and semi-quantitative immunoblotting. Lamin A/C, lamin B1, LAP2, emerin, and nuclear pores all extend throughout the grooves and intranuclear inclusions of PTC. Their distribution and fluorescent intensity is not predictably altered relative to nuclear envelope irregularities. By immunoblotting, the abundance (per cell) and electrophoretic mobilities of lamin A, lamin B1, lamin C, emerin, and LAP2 proteins do not distinguish PTC, normal thyroid, or follicular neoplasms. These results do not support previously published predictions that lamin A/C expression is related to a loss of proliferative activity. At least three LAP2 isoforms are identified in normal and neoplastic thyroid. LBR is sparse or undetectable in all the thyroid samples. The results suggest that the irregular nuclear shape of PTC is not determined by these nuclear envelope structural proteins per se. We review the structure of the nuclear envelope, the major factors that determine nuclear shape, and the possible functional consequences of its alteration in PTC.     

Expression of CD44 and cyclin D1 in fine needle aspiration cytology of papillary thyroid carcinoma

OBJECTIVE: To compare the expression pattern of CD44 and cyclin D1 immunostaining in fine needle aspiration specimens of papillary carcinoma of the thyroid and nonpapillary lesions. STUDY DESIGN: The study was performed on 80 fine needle aspiration cytologic smears of thyroid lesion retrospectively using monoclonal antibodies and on histologic material from a proportion of cases. RESULTS: Most papillary carcinomas expressed intense cell membrane or diffuse cytoplasmic staining for CD44 (97.8%). Focal immunoreactivity was observed in follicular neoplasms (28.5%) and nodular goiter (4.7%). There was no difference in CD44 immunostaining between follicular carcinoma and adenoma. Cyclin D1 was expressed in the nuclei of most papillary carcinomas (79.2%). Focal nuclear immunoreactivity was noted in nodular goiters (23.5%) and follicular neoplasms (10%). In resected specimens, all papillary carcinomas (19 cases) showed intense membranous or granular CD44 immunoreactivity. Focal cyclin D1 expression was noted in 52.6%. There was no difference in CD44 and cyclin D1 expression between the group of papillary carcinomas with regional lymph node metastasis as compared to those without metastasis. Positive staining for both CD44 and cyclin D1 would strongly favor papillary carcinoma, although further studies on cytologic material are necessary to verify this diagnostic approach. CONCLUSION: Most papillary carcinomas express CD44 and cyclin D1, whereas it is less common in follicular neoplasms and nodular goiter. This may be helpful in diagnostically difficult cases.     

Nuclear grooves. Valuable diagnostic feature in May-Grünwald-Giemsa-stained fine needle aspirates of papillary carcinoma of the thyroid.

Recent reports have indicated the usefulness of nuclear grooves (clefts or notches) as an additional criterion for the diagnosis of papillary thyroid carcinoma in fine needle aspirates; most of these studies were carried out on alcohol-fixed material stained with the Papanicolaou stain or with hematoxylin and eosin, which yield good nuclear details. In the present study air-dried thyroid aspirates stained with the widely used May-Grünwald-Giemsa stain were evaluated. Nuclear grooves were observed in 88% of the May-Grünwald-Giemsa-stained aspirates from papillary thyroid carcinoma, usually in substantial numbers. A few grooved nuclei were seen in a small percentage of the other thyroid aspirates studied. These results show that nuclear grooves can also be used as a possible marker of papillary carcinoma of the thyroid in May-Grünwald-Giemsa-stained aspirates.     

Fine needle aspiration cytology of follicular variant of papillary carcinoma of the thyroid: Morphologic pointers to its diagnosis

OBJECTIVE: To study the cytomorphologic features of 59 cases of histologically proven follicular variant of papillary carcinoma (FVPC), compare them to those described in the literature and highlight cytologic features that may aid in the preoperative diagnosis. STUDY DESIGN: Aspiration smears from 59 histologically proven cases of FVPC were examined independently by 2 observers, and a detailed cytologic evaluation was done for architectural, cytologic and nuclear features. surgical RESULTS: On initial cytology of the 59 cases, 36 (61%) were diagnosed aspapillary carcinoma, and 17 of these were subtyped as FVPC. On reviewing the smears, 50 cases were diagnosed as papillary carcinoma, and 33 of them were typed as FVPC; however, 4 cases were diagnosed as benign lesions. Most smears showed moderate to high cellularity, with 55 cases (93%) showing syncytial clusters and 48 (81%) showing microfollicular architecture. Chromatin clearing and nuclear grooves were seen in 55 (93.2%) and 54 (91.52%) cases but were easily detected in only 36 (61%) and 44 (74%) cases, respectively. Thick colloid was identified in 28 cases, and 3 of these cases also showed thin colloid in the background. CONCLUSION: Our findings suggest that syncytial clusters, microfollicular architecture, chromatin clearing and nuclear grooves are strong morphologic pointers to the diagnosis of FVPC.     

Cytopathology of papillary carcinoma of the thyroid by fine needle aspiration

To delineate the cytologic presentation of papillary carcinoma of the thyroid, the fine needle aspiration smears were studied from 87 surgically proven cases. Six diagnostically useful findings were identified: papillary fronds, monolayered sheets, tissue fragments, intranuclear cytoplasmic inclusions, psammoma bodies and multinucleated giant cells. From 1,500 smears on "cold" nodules of the thyroid, 6 known false-negative and 4 false-positive diagnoses for papillary carcinoma were made. The estimated accuracy of the fine needle aspirate diagnosis of papillary carcinoma is 94%.     

Needle tract implantation of papillary carcinoma of the thyroid following aspiration biopsy

A case is reported of a slow-growing papillary carcinoma of the thyroid that caused clinically apparent implantation along the tract of a fine needle aspiration (FNA) biopsy. This appears to be the first report of a cutaneous needle tract metastasis from a papillary thyroid carcinoma. It represents a highly unusual complication of an FNA biopsy of an indolent, slow-growing tumor.     

Fine needle aspiration cytology in a case of diffuse sclerosing carcinoma of the thyroid

The fine needle aspiration (FNA) cytologic findings in a rare case of bilateral diffuse sclerosing carcinoma of the thyroid are described. Along with a generally papillary architecture, the FNA biopsy smears showed a number of features not usually seen in thyroid carcinomas: psammoma bodies, an abundance of squamous metaplasia and a dense inflammatory component. The FNA diagnosis was multifocal papillary carcinoma with squamous metaplasia; histopathologic examination made the final diagnosis.     

Osteoclastomalike anaplastic carcinoma of the thyroid. Diagnosis by fine needle aspiration cytology

Fine needle aspiration (FNA) of a neck mass yielded cytologic specimens containing two cell populations: multinucleated giant cells and smaller, round-to-oval, undifferentiated malignant cells. The giant cells were frequently so numerous as to obscure the other cells. The FNA cytodiagnosis of a rare anaplastic thyroid carcinoma containing osteoclastic giant cells was substantiated by the subsequent exploratory surgery and biopsy specimen. Immunohistochemical staining suggested a dual origin of the two cell populations.