Case Study
An unusual presentation of thyroid cancer Rajaram Burrah, Kuppuswamy Shivakumar, Suraj Manjunath, Rakesh Ramesh and Vipin Goel
Asian Cardiovascular & Thoracic Annals 2015, Vol. 23(3) 335–337 ß The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492314531141 aan.sagepub.com
Abstract Well-differentiated thyroid cancers can present with nodal metastasis that have undergone cystic degeneration. Rarely, mediastinal nodes may undergo cystic changes and pose a diagnostic dilemma, especially if the primary lesion is occult. We describe the case of a patient who presented with a large mediastinal cystic lesion which turned out to be metastasis from thyroid cancer.
Keywords Diagnosis, differential, lymphatic metastasis, mediastinal cyst, thyroid neoplasms
Introduction Well-differentiated thyroid cancer is one of the few malignancies associated with a good prognosis and prolonged survival. Lymph node metastasis does not carry an adverse prognosis, unlike that of other cancers of the head and neck region. Cystic degeneration of the involved lymph nodes and mediastinal spread of thyroid cancers as separate entities have been well described. However, a large mediastinal cystic tumor in association with thyroid cancer is rare.1,2 We encountered one such patient who posed a diagnostic dilemma.
Case report Our patient was a 50-year-old woman who presented with a history of progressive cough and exertional dyspnea for 5 months. On examination of her neck, the trachea was found to be grossly deviated to the left. There was a soft ill-defined lesion in the root of the right neck with bilaterally enlarged level II lymph nodes. Her chest radiograph showed a homogenous opacity in the right upper zone and mediastinum (Figure 1). Computed tomography of the neck and thorax (Figure 2) showed a large homogenous lesion (10 6 cm) occupying the superior mediastinum and extending from the root of the right neck to the right main bronchus. There were calcifications in the wall of the lesion, and no obvious plane in the lateral wall of
the trachea. The mediastinal structures were displaced to the left. Bilaterally enlarged level II cervical lymph nodes were noted, with no lymph nodes in the lower neck or mediastinum (Figure 3). The diagnosis considered was a bronchogenic cyst. Fine-needle aspiration cytology (FNAC) of the lymph nodes was suggestive of papillary carcinoma of the thyroid. When the computed tomography scan was reviewed retrospectively, a small hypodense lesion was visible in the right lobe of the thyroid. The working diagnosis considered was papillary carcinoma of the thyroid with cystic mediastinal metastases or thyroid papillary carcinoma with cervical metastases and a coexisting mediastinal cyst. The procedure planned was a sternotomy and excision of the mediastinal lesion with total thyroidectomy and bilateral modified radical neck dissection. An apron neck incision was made with a vertical limb down to the midline over the sternum. Neck flaps were raised. A sternotomy was performed and the mediastinum and right pleural space were exposed. The cystic mass was found to be free from the tracheal bronchial tree and the vessels, and was excised completely (Figure 4).
Department of Surgical Oncology, St. John’s Medical College Hospital, Bangalore, India Corresponding author: Rajaram Burrah, Department of Surgical Oncology, St. John’s Medical College Hospital, Sarjapur Road, Bangalore, Karnataka 560034, India. Email: [email protected]
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
336
Asian Cardiovascular & Thoracic Annals 23(3)
Figure 1. Chest radiograph showing a well-circumscribed homogenous lesion in the right upper zone and superior mediastinum, with the trachea deviated to the left.
Figure 3. Computed tomography showing a large homogenous lesion with calcifications in its wall. The lesion extended from the root of the neck to the right main bronchus (arrow).
Figure 4. Intraoperative image showing (a) the mediastinal cyst with (b) the great vessels anterior to it. Figure 2. Computed tomography of the neck showing bilateral enlarged level II lymph nodes (arrows).
Total thyroidectomy with central compartment clearance and bilateral neck dissection was carried out, clearing lymph node levels II–V. The XI cranial nerve, internal jugular vein, and sternomastoid muscle were preserved bilaterally. The postoperative course was uneventful, and the patient was discharged on the 5th postoperative day. The histopathology examination revealed multifocal papillary carcinoma involving both lobes of the thyroid, with capsular invasion and focal extrathyroidal spread. The central compartment tissue had 4 metastatic nodes. The neck dissection specimen showed one positive node out of 36 nodes on the right, and one positive node out of 25 nodes on the left. Both
nodes showed extracapsular spread. The cystic lesion showed features of a metastatic node with cystic changes. The patient was referred for radioiodine therapy and is currently undergoing this treatment.
Discussion Well-differentiated thyroid cancers have a high incidence of lymph node metastasis. Nodal metastasis occurs most commonly in the neck and can also occur in the mediastinum. Cystic degeneration in the metastatic node can occur in 40% of cases, and FNAC of these nodes may have a high false-negative
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
Burrah et al.
337
rate of up to 45%.1 Thyroid cancer may rarely present as a large mediastinal cystic lesion which is actually a metastasis from an occult thyroid primary.1–4 This may mislead the surgeon to address the cystic lesion first, especially if the initial FNAC was negative and there was no clinical evidence of thyroid pathology.1 The thyroidectomy specimen of the reported cases of mediastinal cystic metastasis have shown the tumor to be usually around 1 cm and multifocal.1,3 These lesions may have been missed on imaging, therefore missing the opportunity to consider an alternative diagnosis and/or alter the approach of management. Our patient presented with symptoms related to the mediastinal lesion. She had a palpable node on both sides of the neck, and FNAC of the nodes suggested papillary carcinoma from the thyroid. Computed tomography also identified these nodes and showed a small lesion in the right lobe of the thyroid. We were therefore able to address the disease in a single surgery. Well-differentiated thyroid cancers may masquerade as a mediastinal lesion, especially if the primary in the thyroid is occult. Careful review of imaging of the neck may provide clues to the lesion in the thyroid. FNAC of the thyroid lesion, nodes, or mediastinal lesion may confirm the diagnosis and help in the surgical management.
Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest statement None declared.
References 1. Bhamidipati CM, Mukhopadhyay S, Feliu C, Patton B and Dexter E. Cystic metastases of papillary thyroid carcinoma mimicking a primary mediastinal cyst. J Thorac Oncol 2009; 4: 105–106. 2. Suemitsu R, Takeo S, Hamatake M, Yamamoto T, Furuya K and Momosaki S. Thyroid cancer with a cystic mediastinal tumor invading the right main bronchus. Ann Thorac Surg 2010; 89: 296–298. 3. Okumura M, Yasumitsu T, Kotake Y, Ohta M, Ohshima S and Miyauchi A. Three cases of occult thyroid cancer with mediastinal lymph node metastasis manifesting as a mediastinal cyst. Nihon Kyobu Geka Gakkai Zasshi 1990; 38: 2307–2313. 4. Yoshino M, Mizobuchi T, Fujiwara T, Noro M, Akikusa B and Iwai N. Large mediastinal cyst of an ectopic thyroid with small nodules diagnosed as papillary carcinoma. Jpn J Thorac Cardiovasc Surg 2006; 54: 550–554.
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
An unusual presentation of thyroid cancer Rajaram Burrah, Kuppuswamy Shivakumar, Suraj Manjunath, Rakesh Ramesh and Vipin Goel
Asian Cardiovascular & Thoracic Annals 2015, Vol. 23(3) 335–337 ß The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492314531141 aan.sagepub.com
Abstract Well-differentiated thyroid cancers can present with nodal metastasis that have undergone cystic degeneration. Rarely, mediastinal nodes may undergo cystic changes and pose a diagnostic dilemma, especially if the primary lesion is occult. We describe the case of a patient who presented with a large mediastinal cystic lesion which turned out to be metastasis from thyroid cancer.
Keywords Diagnosis, differential, lymphatic metastasis, mediastinal cyst, thyroid neoplasms
Introduction Well-differentiated thyroid cancer is one of the few malignancies associated with a good prognosis and prolonged survival. Lymph node metastasis does not carry an adverse prognosis, unlike that of other cancers of the head and neck region. Cystic degeneration of the involved lymph nodes and mediastinal spread of thyroid cancers as separate entities have been well described. However, a large mediastinal cystic tumor in association with thyroid cancer is rare.1,2 We encountered one such patient who posed a diagnostic dilemma.
Case report Our patient was a 50-year-old woman who presented with a history of progressive cough and exertional dyspnea for 5 months. On examination of her neck, the trachea was found to be grossly deviated to the left. There was a soft ill-defined lesion in the root of the right neck with bilaterally enlarged level II lymph nodes. Her chest radiograph showed a homogenous opacity in the right upper zone and mediastinum (Figure 1). Computed tomography of the neck and thorax (Figure 2) showed a large homogenous lesion (10 6 cm) occupying the superior mediastinum and extending from the root of the right neck to the right main bronchus. There were calcifications in the wall of the lesion, and no obvious plane in the lateral wall of
the trachea. The mediastinal structures were displaced to the left. Bilaterally enlarged level II cervical lymph nodes were noted, with no lymph nodes in the lower neck or mediastinum (Figure 3). The diagnosis considered was a bronchogenic cyst. Fine-needle aspiration cytology (FNAC) of the lymph nodes was suggestive of papillary carcinoma of the thyroid. When the computed tomography scan was reviewed retrospectively, a small hypodense lesion was visible in the right lobe of the thyroid. The working diagnosis considered was papillary carcinoma of the thyroid with cystic mediastinal metastases or thyroid papillary carcinoma with cervical metastases and a coexisting mediastinal cyst. The procedure planned was a sternotomy and excision of the mediastinal lesion with total thyroidectomy and bilateral modified radical neck dissection. An apron neck incision was made with a vertical limb down to the midline over the sternum. Neck flaps were raised. A sternotomy was performed and the mediastinum and right pleural space were exposed. The cystic mass was found to be free from the tracheal bronchial tree and the vessels, and was excised completely (Figure 4).
Department of Surgical Oncology, St. John’s Medical College Hospital, Bangalore, India Corresponding author: Rajaram Burrah, Department of Surgical Oncology, St. John’s Medical College Hospital, Sarjapur Road, Bangalore, Karnataka 560034, India. Email: [email protected]
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
336
Asian Cardiovascular & Thoracic Annals 23(3)
Figure 1. Chest radiograph showing a well-circumscribed homogenous lesion in the right upper zone and superior mediastinum, with the trachea deviated to the left.
Figure 3. Computed tomography showing a large homogenous lesion with calcifications in its wall. The lesion extended from the root of the neck to the right main bronchus (arrow).
Figure 4. Intraoperative image showing (a) the mediastinal cyst with (b) the great vessels anterior to it. Figure 2. Computed tomography of the neck showing bilateral enlarged level II lymph nodes (arrows).
Total thyroidectomy with central compartment clearance and bilateral neck dissection was carried out, clearing lymph node levels II–V. The XI cranial nerve, internal jugular vein, and sternomastoid muscle were preserved bilaterally. The postoperative course was uneventful, and the patient was discharged on the 5th postoperative day. The histopathology examination revealed multifocal papillary carcinoma involving both lobes of the thyroid, with capsular invasion and focal extrathyroidal spread. The central compartment tissue had 4 metastatic nodes. The neck dissection specimen showed one positive node out of 36 nodes on the right, and one positive node out of 25 nodes on the left. Both
nodes showed extracapsular spread. The cystic lesion showed features of a metastatic node with cystic changes. The patient was referred for radioiodine therapy and is currently undergoing this treatment.
Discussion Well-differentiated thyroid cancers have a high incidence of lymph node metastasis. Nodal metastasis occurs most commonly in the neck and can also occur in the mediastinum. Cystic degeneration in the metastatic node can occur in 40% of cases, and FNAC of these nodes may have a high false-negative
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
Burrah et al.
337
rate of up to 45%.1 Thyroid cancer may rarely present as a large mediastinal cystic lesion which is actually a metastasis from an occult thyroid primary.1–4 This may mislead the surgeon to address the cystic lesion first, especially if the initial FNAC was negative and there was no clinical evidence of thyroid pathology.1 The thyroidectomy specimen of the reported cases of mediastinal cystic metastasis have shown the tumor to be usually around 1 cm and multifocal.1,3 These lesions may have been missed on imaging, therefore missing the opportunity to consider an alternative diagnosis and/or alter the approach of management. Our patient presented with symptoms related to the mediastinal lesion. She had a palpable node on both sides of the neck, and FNAC of the nodes suggested papillary carcinoma from the thyroid. Computed tomography also identified these nodes and showed a small lesion in the right lobe of the thyroid. We were therefore able to address the disease in a single surgery. Well-differentiated thyroid cancers may masquerade as a mediastinal lesion, especially if the primary in the thyroid is occult. Careful review of imaging of the neck may provide clues to the lesion in the thyroid. FNAC of the thyroid lesion, nodes, or mediastinal lesion may confirm the diagnosis and help in the surgical management.
Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest statement None declared.
References 1. Bhamidipati CM, Mukhopadhyay S, Feliu C, Patton B and Dexter E. Cystic metastases of papillary thyroid carcinoma mimicking a primary mediastinal cyst. J Thorac Oncol 2009; 4: 105–106. 2. Suemitsu R, Takeo S, Hamatake M, Yamamoto T, Furuya K and Momosaki S. Thyroid cancer with a cystic mediastinal tumor invading the right main bronchus. Ann Thorac Surg 2010; 89: 296–298. 3. Okumura M, Yasumitsu T, Kotake Y, Ohta M, Ohshima S and Miyauchi A. Three cases of occult thyroid cancer with mediastinal lymph node metastasis manifesting as a mediastinal cyst. Nihon Kyobu Geka Gakkai Zasshi 1990; 38: 2307–2313. 4. Yoshino M, Mizobuchi T, Fujiwara T, Noro M, Akikusa B and Iwai N. Large mediastinal cyst of an ectopic thyroid with small nodules diagnosed as papillary carcinoma. Jpn J Thorac Cardiovasc Surg 2006; 54: 550–554.
Downloaded from aan.sagepub.com at Umea University Library on April 7, 2015
