A Study on the Clinical Presentation and the Sensitivity of FNAC in Thyroid Neoplasms

Devakumari, A (2006) A Study on the Clinical Presentation and the Sensitivity of FNAC in Thyroid Neoplasms. Masters thesis, Thanjavur Medical College, Thanjavur.


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INTRODUCTION: Thyroid neoplasm includes both benign and malignant tumours arising in the thyroid gland. Although thyroid cancer accounts for only 1% of all cancers (2% in females & 0.5% in males) it is the commonest endocrine tumour that shows a geographic variation in incidence of tumour, type and natural history. Thyroid cancers are heterogenous group of tumours with variable rates of growth, biological aggressiveness, histologic appearance and response to therapy. These tumours are rare in children increase in frequency with increase in age. Female to male ratio 2.5 : 1. The autopsy incidence of thyroid carcinoma in United States has been reported to be in range of 0.9% to 13%. It is likely that many thyroid cancers detected in these studies are not clinically significant and do not play a role in the clinical course of the patients. The annual mortality from thyroid cancer in the United States is only 6 per million population or approximately 1050 patients per year. This discrepancy between the incidence and mortality rate presumably reflects the favorable prognosis for most of the thyroid cancers although these are capable of aggressive behavior with metastatic disease and ultimately death. In thyroid, Nodules become palpable, if they increase approximately beyond 1 cm in size. In the west 4% of general population has detectable enlargement of thyroid. Although thyroid nodules are common, clinically detectable thyroid cancer is uncommon. FINE NEEDLE ASPIRATION CYTOLOGY is a very useful first line investigation in case of thyroid nodules BAM FORTH (1966) defined FNAC as “Examination of cells obtained by needle or drill biopsy in solid organs or tissue masses or from the cut surface of such material freshly removed by surgical biopsy”. In the thyroid swelling the utility of FINE NEEDLE ASPIRATION CYTOLOGY depends upon the accuracy, with which it can predict Neoplasia in thyroid swelling there by providing, 1. The potential for the avoidance of essentially diagnostic surgery in benign conditions. 2. For the planning of surgical strategy in case of carcinoma. 3. For the avoidance of open biopsy in an advanced carcinoma. 4. The FNAC also establishes the physical characteristic of an isolated swelling in that if fluid is obtained from the cysts, if the cyst is abolished and benign then the FNAC is therapeutic. 5. A recurrent cyst or residual swelling both of which are suspicious of underlying carcinoma, indications for surgery. In this dissertation, the main aim of this present study is to report the observations made regarding the clinical presentation and to find out the sensitivity of FNAC in those thyroid neoplasms ultimately proven by Histo Pathological Examination at Thanjavur Medical College Hospital over a period of two years and two months, that is from January 2004 to February 2006. AIMS OF THE STUDY: 1. To study the distribution of the benign and malignant Thyroid tumours in various age groups of patients. 2. To study the sex distribution of the Thyroid Neoplastic lesions. 3. To appreciate the common symptomatology encountered in patients with thyroid neoplasms. 4. To study the local examination findings suggestive of malignant Thyroid tumours. 5. To find out the common histologic types of benign and malignant Thyroid tumours and calculate their frequency. 6. To calculate the sensitivity of FINE NEEDLE ASPIRATION CYTOLOGY in different types of thyroid neoplasms. 7. To calculate the percentage of false negative reports in FNAC. MATERIALS AND METHODS: This is a study of cases of thyroid neoplasms diagnosed and treated at Thanjavur Medical College Hospital during a period of 2 years & 2 months that is from January 2004 to February 2006. It is both a prospective and a retrospective study. All the histopathologically proven cases of benign and malignant thyroid tumours are included in the study. A thorough history taking and a detailed clinical examination was made in all the cases [Proforma enclosed]. FINE NEEDLE ASPIRATION CYTOLOGY was done as a first line investigation in all these cases. Fine needle aspiration was done by the pathologists as per standard guidelines recommended by Svante. r.Orell.a minimum of 3 aspirations were done, usually with 25 gauge needle. The smears were fixed in isopropyl alcohol and were stained with routine haematoxylin and eosin stains, in a few cases giemsa stains was also used. Apart from basic hematological and radiological investigations [Xrays chest & neck], thyroid profile, IDL examination for vocal cord status and other investigations were done before operating on these patients. The surgical treatment was offered upon the basis of clinical impression and FNAC results mainly. In a few patients even if the FNAC was towards a non neoplastic lesion, surgery was done based upon the clinical suspicion of malignancy. The specimens were fixed with 10% buffered neutral formalin and sent to the pathologist. Apart from gross macroscopic examination and cut section examination, the histopathological examination was made by taking atleast 5 sectionsand processed.3-5 μ thickness sections were cut and stained with haematoxylin and eosin All these specimens were subjected to the histopathological examination and results obtained. This study is directed towards the clinical presentation, the sensitivity of FNAC results and the percentage of false negative FNAC results in the histopathologically proved cases of Thyroid neoplasms. CONCLUSIONS This study on Thyroid neoplasms at Thanjavur Medical College for a period of 2 years and 2 months from January 2004 – February 2006 has led to the following conclusions. 1. About 59.75% of thyroid neoplasms operated were found to be benign and the remaining 40.25% malignant. 2. Follicular adenoma is the commonest type among follicular neoplasms and also the commonest benign thyroid neoplasm. 3. Papillary carcinoma is the most common type of thyroid malignancy. 4. Both benign and malignant thyroid tumors are more frequent in females. Sex ratio for benign tumours is (Male : Female) 1 : 4.4 for malignancy it is 1 : 4.5. 5. About 95.2% of the neoplasms were encountered in 20 – 60 years age group. 6. Benign tumours are common in the third and fourth decade, with a mean age of 38.59 years. 7. Malignant tumors are common in third and fourth decade with mean age of 39.83 years. 8. Painless neck swelling was the commonest presenting symptom in thyroid tumors obstructive features & signs suggestive of malignancy like hard consistency, fixity, presence of lymph adenopathy, recurrent larygeal nerve were encounted in relatively fewer cases. 9. The sensitivity of FNAC in thyroid neoplasms is 85.37% with a sensitivity of 80% for follicular neoplasms and 93.33% for papillary carcinomas. 10. The % of false negative results for Thyroid neoplasm was 14.63% with 20% for follicular neoplasm and 6.66% for papillary carcinoma. 11. FNAC is a highly useful, simple, relatively non traumatic first line investigation tool for thyroid neoplastic lesions with good patient acceptance rate.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Clinical Presentation ; Sensitivity ; Fine Needle Aspiration Cytology (FNAC) ; Thyroid Neoplasms.
Subjects: MEDICAL > General Surgery
Depositing User: Devi S
Date Deposited: 14 May 2018 14:58
Last Modified: 14 May 2018 14:58
URI: http://repository-tnmgrmu.ac.in/id/eprint/7822

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