Submitter: Zendah Inès
Neck swelling: think about thyroid tuberculosis
I.Zendah, H.Daghfous, S.Ben Mrad, F.Tritar.
Thyroid tuberculosis is a rare disease even in endemic countries. The diagnosis is often difficult as the clinical presentation is not specific. We report the case of a 47-year-old woman who presented with a nodular swelling of the neck with throat pain and sweating. Physical examination revealed an anterior swelling. Ultrasonography of the neck revealed a nodular goitre of the pyramidal lobe with cystic change and bilateral multiple hypoechogenic lymphadenitis of the jugular and carotid chains. Thyroid function tests were in the normal range. There was no biological signs of inflammation. Tuberculin test with purified protein derivative was negative. There was no evidence of tuberculosis in any other organ. The patient had surgery which revealed a hypertrophy of the pyramidal lobe which was therefore resected. Microscopic examination section of the thyroid parenchyma and lymph nodes revealed necrotizing epithelioid graunlomas with Langhans’giant cells. The diagnosis of thyroid tuberculosis was therefore made. The patient was put on isoniazid, rifampicin, ethambutol and pyrazinamid during 4 months then isoniazid and rifampicin during 6 months with a favourable outcome. Although seldom observed, tuberculosis should be kept in mind in the differential diagnosis of nodular lesions of the thyroid.
Keywords: Thyroid Tuberculosis, extra-pulmonary tuberculosis, neck swelling, antitubercular treatment.
Thyroid tuberculosis is rare even in endemic countries. Hardly 200 cases have been reported in the world literature. It can present as a mid line neck mass posing the differential diagnosis with other more frequent diagnosis such as thyroglossal duct cyst, lipomas, thyroid tumour, cyst or lymph node. Nevertheless, the diagnosis is important to be made as the treatment is madatory.
A 47-year- old female non smoker, with no past medical history, presented with a 5 month history of a nodular swelling of the neck with throat pain. The patient also reported a nocturnal sweating without fever since one year. There was no history of weight loss, anorexia or asthenia. Physical examination revealed a 2 cm nodular mid line swelling in the anterior neck which seemed to be independent of the thyroid gland. The throat was normal. The temperature was 37°C, the heart rate was 70b/mn, and the blood pressure was 130/80 mm Hg. No lymph node was palpable. Chest examination was normal.Thyroid function tests were in the normal range. The blood count was as follows: haematocrit: 32.7%, haemoglobin: 10.7g/dl, platelets: 424.000/mm3, WBC: 7000/mm3 with a normal differential count. Erythrocyte sedimentation rate was 5 mm in the first hour and the C reactive protein (CRP) was 2.95 mg/l (normal value <5mg/l). SGOT was 25 IU/ml and SGPT was 18 IU/ml. Ultrasonography of the neck revealed a nodular goitre of the pyramidal lobe with cystic change. The rest of the gland had a normal echogenicity and regular margins. Bilateral multiple hypoechogenic lymphadenitis of the jugular and carotid chains were noted. The biggest one was 0.62cm in size. The chest X-ray was normal. Tuberculin test with purified protein derivative was negative.The patient had surgery which revealed a hypertrophy of the pyramidal lobe of the thyroid gland. The rest of the gland was with no abnormality. Resection of the pyramidal lobe was therefore performed. On gross examination, the specimen was whitish and measured 3x1cm. One small lymph node was attached to the specimen. Microscopic examination section of the thyroid parenchyma revealed necrotizing epithelioid graunlomas with Langhans’ giant cells. The lymph node included epitheloid cell granulomas and caseous necrosis. The diagnosis of thyroid and lymph node tuberculosis was therefore made. Acid fast bacilli (AFB) were absent in the sputum. Abdominal ultrasonography revealed no lymph node enlargement. The patient was put on isoniazid (300 mg per day), rifampicin (600 mg per day), ethambutol (1200 mg per day) and pyrazinamid (1500 mg per day) during 2 months then isoniazid and rifampicin during 6 months. The clinical outcome was good. Ultrasonographies of the neck and of the abdomen at 8 months of antitubercular treatment revealed no abnormality of the thyroid gland. The lymph nodes of the jugular and carotid chains disappeared.
Tuberculosis of the thyroid gland, whether primary or secondary, is an extremely rare disease. Only isolated reports and few case series have been reported in the literature even in the endemic countries (1,2). The prevalence varies between 0.1% and 0.6% in histologically diagnosed specimens, including endemic countries (1,3,4,5). However, at least 200 cases are reported by the English language literature since the first case reported by Leber (6,7,8,9,10,11). This rarity is probably explained by the fact that certain tissues such as the heart, the striated muscle, the pancreas and the thyroid are relatively resistant to tuberculous infection. In fact, the current reason of the disease’s rarity is still unknown (12). Thyroid tuberculosis is most of the time secondary that is associated with another location of the disease. In this case the bacillus spreads through haematogenous or lymphogenous route or directly from larynx or tubercular cervical lymphadenitis (13,14).When the tuberculosis doesn’t affect the rest of the body, the thyroid disease is primary. This situation is much rarer and more difficult to explain.
Most of the time, the patients are as in our case middle aged women (14). Dysphagia, dyspnea and more rarely dysphonia are the main symptoms of the disease but the patient may be asymptomatic (15). The dominating clinical presentation is a solitary thyroid nodule that may present a cystic component (13,14,16). Our patient presented a swelling of the anterior neck but thought to be independent of the thyroid gland. Sometimes the patients present with thyrotoxicosis, hypothyroidism, thyroid abscess, thyroid enlargement mimicking cancer, or can show signs of subacute granulomatous thyroiditis (De Quervain’s) or of chronic non-suppurative thyroiditis (11,13,17,18). Moreover, patients show most of the time an euthyroid statue and that was the case of our patient (9,14). The imaging techniques are not very helpful, in establishing the diagnosis neither. Ultrasonography shows most of the time a heterogeneous, hypoechogenic mass that may involve a cystic degeneration (9,19).Contrast-enhanced CT may reveal a necrotic centre with a peripheral rim enhancement related to the caseous lesion with regional lymphadenopathies (19). Tuberculous thyroiditis can mimic many pathologies. The local pain is a chief symptom for the differential diagnosis. If it predominates, the other pathologies to consider are infectious thyroiditis and subacute granulomatous thyroiditis (De Quervain’s, thyroid sarcoidosis etc) (20). In the event that pain is absent, the tuberculous thyroiditis can often be mistaken for carcinoma (21,22,23).As in thyroid tuberculosis patients may present with a nodule, recently lead to include this pathology in the differential diagnosis of thyroid masses. It is however important to notice that tuberculous thyroiditis may coexist with thyroid carcinoma in the same patient (24,25,26).
The diagnosis is most of the time unexpected and mainly made by ultrasound guided fine needle aspiration cytology that can allow the avoidance of surgery (4,27,28,). The diagnosis can also be made definitely post operatively by the mean of histopathological examination of the surgical specimen as for our patient (4,5,14). The characteristic morphologic features of tuberculous infection are necrotizing epithelioid cell granulomas with Langhans’ giant cells. Nevertheless, granulomatous lesions are not pathognomonic of tuberculosis as they may be seen in sarcoidosis and subacute thyroiditis. However, when the caseating necrosis is present the diagnosis of tuberculosis is sure. In this case report the tuberculous origin of the thyroid disease is made certain by the presence of caseaum in the lymph node. The demonstration of AFB in the gland by Ziehl Nelsen stain also makes the diagnosis. However, the mycobacteria is rarely isolated by the stain (15, 29). Results from the cultures should then be waited for (at least 4 weeks) and may be helpful. Nevertheless the specimen is rarely taken for culture as the tuberculosis is rarely suspected.
The lack of specific symptoms associated to the poor role of imaging and the rarity of the presence of the mycobacteria in the stain, added to the possibility of the presence of histological features mimicking other diseases; make the diagnosis of thyroid tuberculosis a real challenge and lead us to wonder if tuberculosis of the thyroid gland is as rare as it is claimed.
The treatment consists on antituberculous drugs combined with surgical removal of the affected parts of the thyroid gland or surgical drainage with a good outcome (4, 5, 27). For some authors drugs alone are sufficient (30). In our patient, surgery was applied for a diagnostic purpose and as the pathologic study revealed tuberculosis, the concerned lobe has been resected.
We added to the surgical treatment the medical one according to our national antituberculosis program. The whole duration of chemotherapy was 8 months with a favourable outcome.
Tuberculosis is an uncommon cause of thyroid disease. It can manifest in various ways with unspecific symptoms. The diagnosis is difficult and thyroid tuberculosis should be differentiated from other diseases of the thyroid gland.
The main method for establishing diagnosis is fine-needle aspiration with subsequent bacterioscopical or bacteriological investigation. Sometimes it is made by the histopathological examination of the resected gland.
The treatment consists on thyroid surgery, antituberculous drugs or repeated puncture drainage procedures. The methods can be associated together. A better knowledge of the disease can avoid surgery in many patients.
1- Collar FA, Huggins CB. Tuberculosis of the thyroid gland. Ann Surg 1926; 84:804-820.
2- Kukreja HK, Sharma ML. Primary tuberculosis of the thyroid gland. Ind J Surg 1982; 44:190.
3-Rankin FW, Graham A.S. Tuberculosis of the thyroid gland. Annals of Surgery 1932;96:625.
4- El Malki HO, Mohsine R, Benkhraba K, Amahzoune M, Benkabbou A, El Absi M, Ifrine L, Belkouchi A, Balafrej S. Thyroid tuberculosis: diagnosis and treatment. Chemotherapy.2006; 52(1):46-9.
5-Kabiri H, Atoini F, Zidane A. Thyroid tuberculosis. Ann Endocrinol 2007;68(2-3):196-8.
6-. Coller FA, Huggins CB. Tuberculosis of the thyroid gland. Ann Surg 1926; 84: 408.
7-Sadykov FG, Mukhtarov RS. Local form of tuberculosis of the thyroid gland in children. Vestn Khir Im I I Grek 1987; 139:114.
8- Pazaitou K, Chrisoulidou A, Ginikopoulou E, Angel J, Destouni C, Vainas I, Primary tuberculosis of the thyroid gland: report of three cases. Thyroid 2002; 12: 1137-1140.
9-Terzidis K, Tourli P,Kiapekou E, Alevizaki M. Thyroid Tuberculosis.Hormones 2007; 6(1):75-79
10-Mondal A, Patra DK. Efficacy of fine needle aspiration cytology in the diagnosis of tuberculosis of the thyroid gland: a study of 18 cases. J Laryngol Otol 1995; 109: 36-38.
11-Ghosh A, Saha S, Bhattacharya B, Chattopadhay S. Primary tuberculosis of thyroid gland: a rare case report. Am J Otolaryngol. 2007;28(4):267-70.
12- Corton R.S, Kumar V, Robbins S.L. In Robbins Pathological basis of disease, 5th edition, 1994. W.B. Saunders Company U.S, pp 326 and 82.
13- Das DK, Pant CS, Chachra KL, Gupta AK. Fine needle aspiration cytology diagnosis of tuberculous thyroiditis. A report of 8 cases. Acta Cytol 1992; 36:517-522.
14- Abdulsalam F, Abdulaziz S, Mallik A. Primary Tuberculosis of the Thyroid Gland. Kuwait Medical Journal 2005; 37 (2): 116-118
15- Khan EM, Haque I, Pandey R, Mishra SK, Sharma AK. Tuberculosis of the thyroid gland: a clinicopathological profile of four cases and review of the literature. Aust NZ J. Surg. 1993; 63:807-810.
16- Surer I, Ozturk H, Cetinkursun S. Unusual presentation of tuberculosis reactivation in childhood: an anterior neck mass. J Pediatr Surg 2000; 35(8):1263-65.
17- Barnes P, Weatherstone R. Tuberculosis of the thyroid. Two case reports. Br J Dis Chest 1979;73:187-191
18- Johnson AG, Phillips ME, Thomas RJS. Acute tuberculous abscess of the thyroid gland. Br J Surg 1973; 60:608
19- Kang BC, Lee SW, Shim SS, Choi HY, Baek SY, Cheon YJ. US and CT findings of tuberculosis of the thyroid gland: three case reports. Clin Imaging 2000; 24(5):283-6.
20- Talwar VK, Gupta H, Kumar A. Isolated tuberculous thyroiditis JIACM 2003;4(3):238-9.
21- Magboo ML, Clark OH. Primary tuberculous thyroid abscess mimicking carcinoma diagnosed by fine needle aspiration biopsy. West J Med 1990; 153(6):657-9.
22- Alan R, O’Flynn W, Clarke SE. Tuberculosis of the thyroid bed presenting as recurrent medullary thyroid carcinoma. Tubercle 1990; 71(4):301-2.
23-Al-Mulhim AA, Zakaria HM, Abdel Hadi MS, Al-Mulhim FA, Al-Tamimi DM, Wosornu L. Thyroid tuberculosis mimicking carcinoma: report of two cases. Surg Today. 2002; 32(12):1064-7.
24-El Kohen A, Essakalli L, Amarti A, Benchekroun L, Jazouli N, Kzadri M. Thyroid tuberculosis associated with papillary microcarcinoma of the thyroid gland: a case report. Rev Laryngol Otol Rhinol 2001;122(3):205-8.
25-Hizawa K, Okamura K, Sato K, Kuroda T, Yoshinari M, Ikenoue H. Tuberculous thyroiditis and miliary tuberculosis manifested postpartum in a patient with thyroid carcinoma.Endocrinol Jpn 1990; 37(4):571-6.
26- Hery A, Rakotoarisoa N, Riel AM, Rakoto, Pierre FA, Randriatahina G, Razafimandimby T, Razafindrakoto HR, Rakotovao FJ. La tuberculose de la glande thyroïde: A propos de deux cas. Fr ORL 2007; 92: 318-320.
27- Simkus A. Thyroid tuberculosis. Medicina (Kaunas). 2004; 40(3):201-4.
28-Bulbuloglu E, Ciralik H, Okur E, Ozdemir G, Ezberci F, Cetinkaya A. Tuberculosis of the thyroid gland: review of the literature. World J Surg. 2006; 30(2):149-55
29-Keven MC, Birengal S, Okca F .Tuberculosis of the thyroid gland: a case report. Clin Microbial Infect 2001; 7:514.
30-El Malki HO, El Absi M, Mohsine R, Ait Taleb K, Chefchaouni MC, Oulbacha S. Tuberculosis of the thyroid. Diagnosis and treatment. Ann Chir 2002; 127(5):385-7.