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CT
Otolaryngology–Head and Neck Surgery (2009) 140, 134-135
CASE REPORT
FDG-positive Warthin’s tumors in cervical lymph nodes mimicking metastases in tongue cancer staging with PET/CT Esther Schwarz, MS, Sandra Hürlimann, MD, Jan David Soyka, MD, Lucia Bortoluzzi, MD, and Klaus Strobel, MD, Zurich and Lucerne, Switzerland
1
8F-fluorodeoxyglucose-positron emission tomography (FDG-PET/CT) is increasingly used for staging of patients with head and neck squamous cell cancers (HNSCC) with significant impact on therapy decisions.1 Additional applications are detection of carcinomas of unknown primary (CUP), detection of secondary cancers, and response assessment after therapy. FDG uptake is not specific for malignant tumors. Many nonmalignant tissues and inflammatory or infectious lesions can take up FDG and cause misinterpretations in cancer patients. We present the case of a 42-year-old male smoker with biopsy-proven SCC of the right anterolateral border of the oral tongue. Partial glossectomy was performed one week prior. Large lymph nodes were palpable in the right neck. The contrast-enhanced neck CT demonstrated two ipsilateral large, partially necrotic neck nodes at level II, suspicious for lymph node metastases, and the patient was referred for further staging to our institution. A partial-body PET/CT after injection of 350 Mbq FDG was performed (Fig 1). PET/CT demonstrated intense radiotracer uptake with a maximum standardized uptake value (SUV max. 5.2) at the resection site of the former primary tumor on the right-sided anterior border of the oral tongue representing postoperative changes. Additionally, intense FDG uptake (SUV max. 9.5 and 5.7) in the ipsilateral enlarged lymph nodes of level II was observed. Again, the diagnosis of SCC lymph node metastases was established by FDG-PET/CT. By imaging, the tumor was staged pT2cN2bcM0 according to the UICC staging system. Bilateral elective supraomohyoid neck dissection was carried out subsequently. In pathology three Warthin’s tumors (cystadenolymphomas) in three right-sided lymph nodes, 4.5 cm in greatest dimension, were found. All the other lymph nodes in the neck dissection were free of tumor. Finally, the tumor was classified as pT2pN0cM0. We have Institutional Review Board approval for this study.
Figure 1 FDG-PET/CT (a ⫽ MIP, b ⫽ axial PET, c ⫽ axial CT, d ⫽ axial fused PET/CT) images of a 42-year-old man with known squamous cell carcinoma of the right lateral border of the oral tongue after partial glossectomy. FDG uptake in the rightsided border of the oral tongue (long arrows) representing postoperative changes. Partially contrast-enhancing Warthin’s tumor (short arrows) in a level II lymph node directly adjacent to the tail of the parotid gland on the right side with intense FDG uptake (other Warthin’s tumors are not shown). Moderate bilateral symmetric physiological uptake in the calcified tonsils (arrowheads).
DISCUSSION This case demonstrates FDG-active Warthin’s tumors (cystadenolymphomas) in neck lymph nodes misleading to the diagnosis of lymph node metastases of a tongue cancer on CT and PET/CT images. Several publications showed that metabolic imaging with FDG-PET/CT is superior to purely morphologic imaging modalities like CT, MRI, or ultrasound
Received May 19, 2008; revised September 17, 2008; accepted September 17, 2008.
0194-5998/$36.00 © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.09.019
Schwarz et al
FDG-positive Warthin’s tumors in cervical lymph nodes . . .
135
imaging. Radiologists, nuclear physicians, and head and neck surgeons should be aware of the potential pitfalls of CT and PET/CT imaging to avoid inaccurate staging and treatment decisions. FDG-uptaking lesions in neck nodes, especially if not fitting to the localization and lymphatic spread of the primary tumor—as in our case—and if they are located in or near the parotid gland, should be further evaluated by fine needle biopsy prior to surgery.
AUTHOR INFORMATION
Figure 2 Warthin’s tumor (2) in a lymph node (arrow: lymph node with marginal sinus) with focal adjacent serous salivary gland tissue from parotid gland (1).
From the Division of Nuclear Medicine, Department of Medical Radiology, University Hospital Zurich, Switzerland (Ms Schwarz, Dr Soyka, Dr Strobel); and the Institute of Pathology (Dr Hürlimann) and Department of Otorhinolaryngology–Head and Neck Surgery (Dr Bortoluzzi), Cantonal Hospital Lucerne, Switzerland. Corresponding author: Klaus Strobel, MD, Division of Nuclear Medicine, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland. E-mail address: [email protected].
2
regarding lymph node staging in patients with HNSCC. Despite the high accuracy of PET/CT regarding dignity of neck lymph nodes, it is known that inflammatory lymph nodes might lead to false-positive and necrotic lymph nodes can lead to false negative PET/CT results. Several other pitfalls of FDG-PET/CT imaging in the head and neck region exist: physiological FDG uptake by brown adipose tissue, salivary glands, areas with lymphoepithelial tissue, and musculature can be observed.3 Warthin’s tumors are known benign lesions with high FDG uptake. They are often incidentally encountered inside the parotid gland, especially in PET/CT studies of smokers with lung cancer.4 As far as we know, this is the first description of multiple FDG-positive histologically proven Warthin’s tumors in lymph nodes of a head and neck cancer patient. Warthin’s tumor is usually located in the parotid gland and rarely seen outside the parotid gland. Histopathology of these tumors is composed of glandular and often cystic structures, sometimes with a papillary cystic arrangement, lined by characteristic bilayered epithelium, comprising inner columnar eosinophilic or oncocytic cells surrounded by smaller basal cells (Fig 2). Occasionally, Warthin’s tumors occur in cervical lymph nodes where they can mimic metastatic disease. Coincidence of Warthin’s tumors and SCC of the aerodigestive tract might be explained by the association with similar risk factors of these tumor entities, such as nicotine and alcohol abuse. This case demonstrates the difficulty of the differentiation of lymph node metastases and Warthin’s tumors by
AUTHOR CONTRIBUTIONS E. Schwarz, data collection, writer, literature search; Dr Hürlimann, data collection, images, corrections; Dr Soyka, corrections, images; Dr Bortoluzzi, data collection, corrections; Dr Strobel, concept, writing, images.
FINANCIAL DISCLOSURE None.
REFERENCES 1. Fleming AJ Jr, Smith SP Jr, Paul CM, et al. Impact of [18F]-2fluorodeoxyglucose-positron emission tomography/computed tomography on previously untreated head and neck cancer patients. Laryngoscope 2007;117:1173–9. 2. Adams S, Baum RP, Stuckensen T, et al. Prospective comparison of 18F-FDG PET with conventional imaging modalities (CT, MRI, US) in lymph node staging of head and neck cancer. Eur J Nucl Med 1998; 25:1255– 60. 3. Yeung HW, Grewal RK, Gonen M, et al. Patterns of (18)F-FDG uptake in adipose tissue and muscle: a potential source of false-positives for PET. J Nucl Med 2003;44:1789 –96. 4. Lardinois D, Weder W, Roudas M, et al. Etiology of solitary extrapulmonary positron emission tomography and computed tomography findings in patients with lung cancer. J Clin Oncol 2005;23:6846 –53.
CASE REPORT
FDG-positive Warthin’s tumors in cervical lymph nodes mimicking metastases in tongue cancer staging with PET/CT Esther Schwarz, MS, Sandra Hürlimann, MD, Jan David Soyka, MD, Lucia Bortoluzzi, MD, and Klaus Strobel, MD, Zurich and Lucerne, Switzerland
1
8F-fluorodeoxyglucose-positron emission tomography (FDG-PET/CT) is increasingly used for staging of patients with head and neck squamous cell cancers (HNSCC) with significant impact on therapy decisions.1 Additional applications are detection of carcinomas of unknown primary (CUP), detection of secondary cancers, and response assessment after therapy. FDG uptake is not specific for malignant tumors. Many nonmalignant tissues and inflammatory or infectious lesions can take up FDG and cause misinterpretations in cancer patients. We present the case of a 42-year-old male smoker with biopsy-proven SCC of the right anterolateral border of the oral tongue. Partial glossectomy was performed one week prior. Large lymph nodes were palpable in the right neck. The contrast-enhanced neck CT demonstrated two ipsilateral large, partially necrotic neck nodes at level II, suspicious for lymph node metastases, and the patient was referred for further staging to our institution. A partial-body PET/CT after injection of 350 Mbq FDG was performed (Fig 1). PET/CT demonstrated intense radiotracer uptake with a maximum standardized uptake value (SUV max. 5.2) at the resection site of the former primary tumor on the right-sided anterior border of the oral tongue representing postoperative changes. Additionally, intense FDG uptake (SUV max. 9.5 and 5.7) in the ipsilateral enlarged lymph nodes of level II was observed. Again, the diagnosis of SCC lymph node metastases was established by FDG-PET/CT. By imaging, the tumor was staged pT2cN2bcM0 according to the UICC staging system. Bilateral elective supraomohyoid neck dissection was carried out subsequently. In pathology three Warthin’s tumors (cystadenolymphomas) in three right-sided lymph nodes, 4.5 cm in greatest dimension, were found. All the other lymph nodes in the neck dissection were free of tumor. Finally, the tumor was classified as pT2pN0cM0. We have Institutional Review Board approval for this study.
Figure 1 FDG-PET/CT (a ⫽ MIP, b ⫽ axial PET, c ⫽ axial CT, d ⫽ axial fused PET/CT) images of a 42-year-old man with known squamous cell carcinoma of the right lateral border of the oral tongue after partial glossectomy. FDG uptake in the rightsided border of the oral tongue (long arrows) representing postoperative changes. Partially contrast-enhancing Warthin’s tumor (short arrows) in a level II lymph node directly adjacent to the tail of the parotid gland on the right side with intense FDG uptake (other Warthin’s tumors are not shown). Moderate bilateral symmetric physiological uptake in the calcified tonsils (arrowheads).
DISCUSSION This case demonstrates FDG-active Warthin’s tumors (cystadenolymphomas) in neck lymph nodes misleading to the diagnosis of lymph node metastases of a tongue cancer on CT and PET/CT images. Several publications showed that metabolic imaging with FDG-PET/CT is superior to purely morphologic imaging modalities like CT, MRI, or ultrasound
Received May 19, 2008; revised September 17, 2008; accepted September 17, 2008.
0194-5998/$36.00 © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.09.019
Schwarz et al
FDG-positive Warthin’s tumors in cervical lymph nodes . . .
135
imaging. Radiologists, nuclear physicians, and head and neck surgeons should be aware of the potential pitfalls of CT and PET/CT imaging to avoid inaccurate staging and treatment decisions. FDG-uptaking lesions in neck nodes, especially if not fitting to the localization and lymphatic spread of the primary tumor—as in our case—and if they are located in or near the parotid gland, should be further evaluated by fine needle biopsy prior to surgery.
AUTHOR INFORMATION
Figure 2 Warthin’s tumor (2) in a lymph node (arrow: lymph node with marginal sinus) with focal adjacent serous salivary gland tissue from parotid gland (1).
From the Division of Nuclear Medicine, Department of Medical Radiology, University Hospital Zurich, Switzerland (Ms Schwarz, Dr Soyka, Dr Strobel); and the Institute of Pathology (Dr Hürlimann) and Department of Otorhinolaryngology–Head and Neck Surgery (Dr Bortoluzzi), Cantonal Hospital Lucerne, Switzerland. Corresponding author: Klaus Strobel, MD, Division of Nuclear Medicine, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland. E-mail address: [email protected].
2
regarding lymph node staging in patients with HNSCC. Despite the high accuracy of PET/CT regarding dignity of neck lymph nodes, it is known that inflammatory lymph nodes might lead to false-positive and necrotic lymph nodes can lead to false negative PET/CT results. Several other pitfalls of FDG-PET/CT imaging in the head and neck region exist: physiological FDG uptake by brown adipose tissue, salivary glands, areas with lymphoepithelial tissue, and musculature can be observed.3 Warthin’s tumors are known benign lesions with high FDG uptake. They are often incidentally encountered inside the parotid gland, especially in PET/CT studies of smokers with lung cancer.4 As far as we know, this is the first description of multiple FDG-positive histologically proven Warthin’s tumors in lymph nodes of a head and neck cancer patient. Warthin’s tumor is usually located in the parotid gland and rarely seen outside the parotid gland. Histopathology of these tumors is composed of glandular and often cystic structures, sometimes with a papillary cystic arrangement, lined by characteristic bilayered epithelium, comprising inner columnar eosinophilic or oncocytic cells surrounded by smaller basal cells (Fig 2). Occasionally, Warthin’s tumors occur in cervical lymph nodes where they can mimic metastatic disease. Coincidence of Warthin’s tumors and SCC of the aerodigestive tract might be explained by the association with similar risk factors of these tumor entities, such as nicotine and alcohol abuse. This case demonstrates the difficulty of the differentiation of lymph node metastases and Warthin’s tumors by
AUTHOR CONTRIBUTIONS E. Schwarz, data collection, writer, literature search; Dr Hürlimann, data collection, images, corrections; Dr Soyka, corrections, images; Dr Bortoluzzi, data collection, corrections; Dr Strobel, concept, writing, images.
FINANCIAL DISCLOSURE None.
REFERENCES 1. Fleming AJ Jr, Smith SP Jr, Paul CM, et al. Impact of [18F]-2fluorodeoxyglucose-positron emission tomography/computed tomography on previously untreated head and neck cancer patients. Laryngoscope 2007;117:1173–9. 2. Adams S, Baum RP, Stuckensen T, et al. Prospective comparison of 18F-FDG PET with conventional imaging modalities (CT, MRI, US) in lymph node staging of head and neck cancer. Eur J Nucl Med 1998; 25:1255– 60. 3. Yeung HW, Grewal RK, Gonen M, et al. Patterns of (18)F-FDG uptake in adipose tissue and muscle: a potential source of false-positives for PET. J Nucl Med 2003;44:1789 –96. 4. Lardinois D, Weder W, Roudas M, et al. Etiology of solitary extrapulmonary positron emission tomography and computed tomography findings in patients with lung cancer. J Clin Oncol 2005;23:6846 –53.