Original Article Histopathological Pattern of Diagnoses in Patients Undergoing Thyroid Operations Champa Sushel, Tariq Wahab Khanzada, Imrana Zulfikar, Abdul Samad From Department of Surgery, Isra University Hospital, Hyderabad, Pakistan. Correspondence: Dr. Champa Sushel, B 15/1, Gulshan-e-Abbass Society Citizen Colony, Hyderabad, Pakistan. Tel:022-2030161-70. E-mail: champasushel@yahoo.com Received: September 23, 2008 Accepted: November 18, 2008 ABSTRACT Objective: To determine the pattern of histopathological diagnoses in patients undergoing thyroid operations. Material and Method: This descriptive study was carried out at Isra University Hospital, Hyderabad over a period of 3 years from May 2005 to April 2008. Patients having goiters and undergoing different types of thyroid surgeries for different indications were included in this study. Fine needle aspiration cytology (FNAC) was performed in patients with thyroid nodule or dominant nodule and was compared with postoperative histopathology. Those patients who underwent only FNAC but were not operated were excluded from the study. Results: Out of 140 thyroid surgical specimens, 125 (89%) were diagnosed to be having nonneoplastic lesions and were more common in females. Adenomatous goiter was the most common variety of benign lesions accounting for 60% of all thyroid nodules. Papillary carcinoma was the commonest thyroid malignancy and was observed in 60% of all thyroid malignancies seen. Conclusion: Benign thyroid lesions were more common than malignant ones. Adenomatous goiter was the commonest benign lesion of the thyroid gland while papillary carcinoma was the most common malignant tumor of thyroid gland. (Rawal Med J 2009;34:14-16). Key words: Colloid goiter, follicular adenoma, thyroid carcinoma, papillary carcinoma. 1
INTRODUCTION Thyroid disorders are one of the common problem encountered in clinical practice with majority of them benign in nature. 1 They are endemic in mountainous regions of the world where the soil, water, and food supply contain little iodine. 2 In Pakistan, an alarmingly high prevalence of iodine deficiency goiter has been reported from the northern areas of the country in the lap of Himalayas. 3 Long-standing goiter (more than 5 years) is regarded as the one of the strongest risk factor for the development of thyroid cancer. Thyroid cancer is a relatively rare malignancy representing only 1.5% of all cancer but it is the commonest endocrine cancer accounting for 92% of all endocrine malignancies. 4 Papillary carcinoma is the most common thyroid cancer followed by follicular, medullary, anaplastic and lymphoma. The objective of this study was to determine the spectrum of histopathological diagnoses encountered in patients undergoing thyroid operations. MATERIALS AND METHODS This descriptive study was carried out at Isra University Hospital, Hyderabad and in another private hospital of Hyderabad over a period of 3 years from May 2005 to April 2008. All patients presenting with thyroid swelling and undergoing any type of thyroid operation were included in the study. Those patients in whom fine needle aspiration cytology (FNAC) was done but they did not undergo thyroid surgery were excluded from the study. FNAC was carried out in patients having dominant or solitary nodule. All patients had a preoperative indirect laryngoscopy to exclude pre existing vocal cord pathology. Near total thyroidectomy was the commonest surgical procedure in cases of multinodular goiters and lobectomy was done in patients having solitary nodule. Detailed information including name, age, gender, clinical status (hypothyroid/ hyperthyroid/ euthyroid), any previous history of thyroid 2
surgery, relevant investigations like FNAC, thyroid scan, ultrasound reports and operative findings were provided to histopathologist. RESULTS A total of 140 patients fulfilled the selection criteria. The gender distribution was predominantly females (n=126), making up to 90% of total population with female to male ratio was 9:1. The mean age was 32 years (range 16-68 years). Table 1. Histopathological types of thyroid lesions (n=140). S. No Histopathological diagnosis Number % 1 Adenomatous goiter 84 60 2 Follicular adenoma 38 27.1 3 Papillary carcinoma 11 7.85 4 Follicular carcinoma 03 2.1 5 Lymphocytic thyroiditis 03 2.1 6 Anaplastic carcinoma 01 0.71 Out of 140 specimens, 125 (89%) were benign and 15 (11%) were malignant. Among 125 benign lesions, the commonest pathological lesion encountered was adenomatous goiter accounting for 68% of all benign and 60% of all thyroid lesions. Other less common benign lesions were follicular adenoma and lymphocytic thyroiditis observed in 38 (27.1%) and 3 (2%) patients respectively (table 1). Table 2. Histopathological types of thyroid cancers (n=15). S. No Histopathological diagnosis Number Percentage 1 Papillary carcinoma 11 73.3 2 Follicular carcinoma 03 20 3 Anaplastic carcinoma 01 6.7 3
Among 140 patients, 15 patients (11%) had thyroid malignancy and papillary carcinoma was found to be the commonest malignant thyroid lesion, observed in (11/15) 73.3% of all thyroid malignant lesions. This was followed by follicular carcinoma seen in (3/15) 20% of all malignant lesions, while anaplastic carcinoma was seen in one patient (table 2). DISCUSSION Thyroid enlargement in the form of solitary, multinodular or diffuse goiter is inexplicably frequent surgical problem and affect approximately one-third of adult world population. 5 Today thyroidectomy is a routine procedure because of the introduction of safe anesthesia, antiseptics, fine surgical instruments and developments of new techniques, offering the chances of cure to many patients. 6 The overall incidence of non neoplastic lesions in this study was 89% as compared to 11% of neoplastic lesions. These results are supported with some local studies 7-9 as well as studies from Yemen 10 and East Africa 11 whereas some other local studies reported a significantly high incidence of thyroid malignancies, observed in about 26% to 36.6% of patients respectively. 12-14 The commonest non-neoplastic lesion in this study was adenomatous goiter including diffuse and multinodular goiters which constituted 60% of the thyroid specimens. This is consistent with some local studies in which multinodular goiter and diffuse adenomatous goiters were found to be the commonest pathologies of the thyroid lesions. 2,4,15-17 Follicular adenomas were seen in 27.1% of the specimens and it was the 2 nd most common benign thyroid lesion. This finding is consistent with the observation of Suster 18 and Bouq 6 but in contrast Virk et al showing follicular adenoma to be more common than colloid goiter (65%Vs30%). 19 Patients with clinically discrete solitary nodules in whom FNAC showing follicular lesion should always undergo total lobectomy to exclude the diagnosis of follicular carcinoma on final histopathology report. 4
Variety of inflammatory conditions affect the thyroid gland, these may be focal or diffuse and often associated with thyroid dysfunction. In this study, 2% patients had thyroiditis, all of which were of lymphocytic type as seen in some national studies. 4,20 Variation in the frequencies of thyroid carcinomas has been observed in various parts of the world. The overall incidence of malignancy in this study was about 11%, as reported in various international studies. 21 In this study, papillary carcinoma was the most common malignant thyroid lesion observed in about 70% (11/15) of the lesions. Although this observation is consistent with several other studies, 7,19, 22 in reports from Nigeria, follicular carcinoma was the commonest thyroid cancer. 23 In conclusion, benign thyroid lesions were more common than malignant lesions. Adenomatous goiter was the commonest lesion observed in thyroid specimens. Papillary carcinoma was the commonest thyroid cancer followed by follicular carcinoma. REFERENCES 1. Burguera B, Gharib H. Thyroid incidentalomas. Prevalence, diagnosis, significance and management. Endocrinol Metab Clin North Am 2000;29:187-203. 2. Elahi S, Manzoor-ul-Hassan A, Syed Z, Nazeer L, Nagra SA, Hyder SW. A study of goiter among female adolescents referred to centre for nuclear medicine, Lahore. Pak J Med Sci 2005;21:56-61. 3. Akhtar T, Zahoorullah, Paracha PI, Lutfullah. Impact assessment of salt iodization on the prevalence of goiter in district Swat. Pak J Med Sci 2004;20:303-7. 4. Niazi S, Arshad M, Muneer M. A histopathological audit of thyroid surgical specimens. Annals King Edward Med Coll 2007;13:51-6. 5
5. Galofré JC, Lomvardias S, Davies TF. Evaluation and treatment of thyroid nodules: a clinical guide. Mt Sinai J Med. 2008;75:299-311. 6. Bouq YA, Fazili FM, Gaffar HA. A current pattern of surgically treated thyroid diseases in the Medinah region of Saudi Arabia. JK- Practitioner 2006;13:9-14. 7. Hussain N, Anwar. M, Nadia N, Ali Z. Pattern of surgically treated thyroid diseases in Karachi. Biomedical 2005;21:18-20. 8. Parvez M, Malik AM, Anwar A. Solitary thyroid nodules: Incidence of thyroid cancers. Pak J Pathol 2001;12:25-9. 9. Akhtar S, Khan AZ, Ahmed M, Osman L, Ahmed F, Chaudhry AM. Correlation of clinical presentation with investigations and operative findings in solitary nodule thyroid. Ann King Edward Med Coll 2001;7:158-61. 10. Al-Hureibi KA, Abdulmughni YA, Al-Hureibi MA. The epidemiology, pathology and management of goiter in Yemen. Ann Saudi Med 2004;24:119-23. 11. Tsegaye B, Ergete W. Histopathological pattern of thyroid disease. East Afr Med J 2003; 80:525-8. 12. Bukhari U, Sadiq S. Histopathological audit of goiter: A study of 998 thyroid lesions. Pak J Med Sci 2008;24:442-6. 13. Niazi S, Bukhari MH, Qureshi GR. Morphological evaluation of non neoplastic lesions of the thyroid gland. Ann King Edward Coll. 2006;12:333-5. 14. Iqbal M, Rasheed K, Iqbal M, Khan A. Aetiology of solitary thyroid nodule. J Surg Pakistan 2002;7:28-30. 15. Imran AA, Majid A, Khan SA. Diagnosis of Enlarged thyroid-an analysis of 250 cases. Ann King Edward Med Coll 2005;11:203-4. 6
16. Sarfraz T, Khalilullah M, Muzaffar M. The frequency and histological types of thyroid carcinoma in northern Pakistan. Pak Armed Forces Med J 2000;50:98-101. 17. Ahmed M, Malik Z, Janjua SA. Surgical audit of solitary thyroid nodule. Pak Armed Forces Med J 2001;51:106-10. 18. Suster S. Thyroid tumor with a follicular growth pattern: problem in differential diagnosis. Arch Pathol Lab Med 2006;130:984-8. 19. Virk NM, Azeem M, Abbar M, Cheema LM. The pattern of thyroid disease in non-toxic solitary thyroid nodule. Ann King Edward Med Coll 2001;7:245-6. 20. Qureshi N, Jaffar R, Ahmed N, Nagi WA. Causes of goiter. A morphological analysis. Biomedical 1996;12:54-6. 21. Al-Ghamdi SAA, Ali Reza M, Al-Shehri G. The pattern of surgically treated thyroid diseases in the Bisha Region of Saudi Arabia. Ann Saudi Med 2002;5:409-10. 22. Khan AZ, Naqi SA, Kamal A, Abaid KJ. Thyroidectomy in carcinoma thyroid-a three years experience. Ann King Edward Med Coll. 2004;10:368-9. 23. Nggada HA, Ojo OS, Adelusola KO. A histopathological analysis of thyroid diseases in Ileife, Nigeria. A review of 274 cases. Niger Postgrad Med J 2008;15:47-51. 7