Fine needle aspiration (FNA) of the thyroid, which is a rapid and cost-effective procedure, has gained wide acceptance as a valuable method for distinguishing neoplastic from non-neoplastic nodules and identifying those patients requiring surgery 1-4. At the present time, the thyroid gland is the most frequently aspirated organ for triage/diagnostic purposes. Clinically-relevant thyroid nodules occur in 5-10% of the general population in Italy and approximately 5% of the patients have malignant lesions. The goal of thyroid FNA is to identify the nodules that require surgery and decrease the number of thyroidectomy for patients with benign disease. Overall, the technique has a high sensitivity and specificity for the detection of thyroid neoplasm 5-7. Cell blocks (CBs) are often prepared on FNAs from several organ sites as an adjunct to smears in the diagnosis of potential lesions. However, the literature contains few reports on their utility with regard to specific organ sites. The main advantage of the CB is the potential to produce several sections for special stains and other ancillary, in particular immunoistochemical, studies 8-10. At our institution, CBs are made routinely on thyroid FNAs since twenty years and we have been performing about eight-hundred thyroid FNAs each year. As a result, we have been collecting a high number of CB of thyroid lesions, of great value for investigative and retrospective studies. The aspirates were procured by experienced cytopathologists, clinicians, or radiologists. The majority of the aspirates were performed by the radiologist or clinicians under ultrasound guidance and each aspirate had an immediate in situ assessment for adequacy by the cytopathologist. FNAs were performed using a 23- or 25-gauge needle attached to a 10-ml disposable syringe mounted to a metallic Cameco syringe pistol (Morton Medical Ltd., London, United Kingdom). One to 4 aspirates were performed per case. After each sampling, air-dried Hematoxylin & Eosin-stained slides were made for immediate assessment and alcohol-fixed slides for subsequent Papanicolaou (Pap) staining. The residual material and the needles were rinsed immediately in a 50% Ethanol solution (s.c. Lysis Buffer) containing Ammonia Chloride, Potassium Bicarbonate and EDTA, which proved effective for fixing cells and lysing erythrocytes. Material collected by centrifugation was embedded in paraffin.presence of cellular fragments. CB has greatly improved the pre-surgical diagnosis of thyroid nodules, since small tissue specimens representative of the lesion were detected in the great majority of cases. These “micro-biopsies” provided morphologically-relevant data. Besides, sections were employed for immunoistochemical and molecular tests. Expression of galectin-3 is routinely tested on thyroid follicular lesions (cytological cell-blocks) obtained preoperatively by ultrasound-guided fine-needle aspiration of thyroid nodules 11. Moreover, CB procedure provides the basis for new molecular and immunoistochemical studies to determine the definition of thyroid neoplasm of indeterminate malignant behavior (Thy3). Recently, we focused on the immunohistochemistry of Emerin, a protein of the nuclear membrane (NM) whose decoration best demarcates the nuclear shape of the thyrocytes 12 and we performed this stain on a series of 82 cytological CB thyroid specimens. Emerin revealed a uniform arrangement of the NM in non-neoplastic lesions (thyroiditis, microfollicular goiter, follicular adenoma) and normal thyroid as well as in follicular carcinoma. In contrast, irregular folding of the membrane and presence of curling and invaginations, eventually leading to the formation of nuclear pseudoinclusions, was observed in PTC and VFPTC cells. In conclusions, the integration of CB method with conventional cytomorphological and clinical diagnostic procedures represents a sensitive and reliable diagnostic approach for preoperative identification of thyroid carcinomas. This procedure improves the diagnostic accuracy of conventional cytology. Moreover, the CB is useful for immunoistochemical and molecular study of thyroid neoplasm
Microembedding in thyroid cytology / S. Asioli; D. Pacchioni; F. Maletta; G. Accinelli; G. Bussolati. - In: PATHOLOGICA. - ISSN 1591-951X. - STAMPA. - 101:(2009), pp. 197--. (Intervento presentato al convegno 5th National Symposium on Cytopathology tenutosi a Torino nel 8-10 novembre 2009).
Microembedding in thyroid cytology.
ASIOLI, SOFIA;
2009
Abstract
Fine needle aspiration (FNA) of the thyroid, which is a rapid and cost-effective procedure, has gained wide acceptance as a valuable method for distinguishing neoplastic from non-neoplastic nodules and identifying those patients requiring surgery 1-4. At the present time, the thyroid gland is the most frequently aspirated organ for triage/diagnostic purposes. Clinically-relevant thyroid nodules occur in 5-10% of the general population in Italy and approximately 5% of the patients have malignant lesions. The goal of thyroid FNA is to identify the nodules that require surgery and decrease the number of thyroidectomy for patients with benign disease. Overall, the technique has a high sensitivity and specificity for the detection of thyroid neoplasm 5-7. Cell blocks (CBs) are often prepared on FNAs from several organ sites as an adjunct to smears in the diagnosis of potential lesions. However, the literature contains few reports on their utility with regard to specific organ sites. The main advantage of the CB is the potential to produce several sections for special stains and other ancillary, in particular immunoistochemical, studies 8-10. At our institution, CBs are made routinely on thyroid FNAs since twenty years and we have been performing about eight-hundred thyroid FNAs each year. As a result, we have been collecting a high number of CB of thyroid lesions, of great value for investigative and retrospective studies. The aspirates were procured by experienced cytopathologists, clinicians, or radiologists. The majority of the aspirates were performed by the radiologist or clinicians under ultrasound guidance and each aspirate had an immediate in situ assessment for adequacy by the cytopathologist. FNAs were performed using a 23- or 25-gauge needle attached to a 10-ml disposable syringe mounted to a metallic Cameco syringe pistol (Morton Medical Ltd., London, United Kingdom). One to 4 aspirates were performed per case. After each sampling, air-dried Hematoxylin & Eosin-stained slides were made for immediate assessment and alcohol-fixed slides for subsequent Papanicolaou (Pap) staining. The residual material and the needles were rinsed immediately in a 50% Ethanol solution (s.c. Lysis Buffer) containing Ammonia Chloride, Potassium Bicarbonate and EDTA, which proved effective for fixing cells and lysing erythrocytes. Material collected by centrifugation was embedded in paraffin.presence of cellular fragments. CB has greatly improved the pre-surgical diagnosis of thyroid nodules, since small tissue specimens representative of the lesion were detected in the great majority of cases. These “micro-biopsies” provided morphologically-relevant data. Besides, sections were employed for immunoistochemical and molecular tests. Expression of galectin-3 is routinely tested on thyroid follicular lesions (cytological cell-blocks) obtained preoperatively by ultrasound-guided fine-needle aspiration of thyroid nodules 11. Moreover, CB procedure provides the basis for new molecular and immunoistochemical studies to determine the definition of thyroid neoplasm of indeterminate malignant behavior (Thy3). Recently, we focused on the immunohistochemistry of Emerin, a protein of the nuclear membrane (NM) whose decoration best demarcates the nuclear shape of the thyrocytes 12 and we performed this stain on a series of 82 cytological CB thyroid specimens. Emerin revealed a uniform arrangement of the NM in non-neoplastic lesions (thyroiditis, microfollicular goiter, follicular adenoma) and normal thyroid as well as in follicular carcinoma. In contrast, irregular folding of the membrane and presence of curling and invaginations, eventually leading to the formation of nuclear pseudoinclusions, was observed in PTC and VFPTC cells. In conclusions, the integration of CB method with conventional cytomorphological and clinical diagnostic procedures represents a sensitive and reliable diagnostic approach for preoperative identification of thyroid carcinomas. This procedure improves the diagnostic accuracy of conventional cytology. Moreover, the CB is useful for immunoistochemical and molecular study of thyroid neoplasmI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
