July 2024 Medical Image of the Month: Vocal Cord Paralysis on PET-CT

Figure 1.  Axial image from a CT scan (A) showing a spiculated left upper lobe nodule.  An axial image from a more inferior slice, at the level of the left hilum (B), demonstrates prominent left hilar adenopathy filling the AP window/subaortic space (*).

Figure 2.  Axial images from an FDG-PET CT obtained shortly after the initial chest CT demonstrates focal hypermetabolic activity associated with the left upper lobe nodule (A) and pre-aortic adenopathy (arrowhead).  There is also hypermetabolism associated with the right (contralateral) vocal cord (B) (arrow).

A 60-year-old woman with a past medical history of hypertension, rheumatoid arthritis, and a significant smoking history (40+ pack-years) presented with a 3-month history of hoarseness of voice as well as a 10 lb weight loss over a 5-month period.  Chest CT revealed a spiculated left upper lobe nodule (Figure 1A). Additionally, there was evidence of bulky mediastinal and left hilar lymphadenopathy (Figure 1B). A subsequent 17-FDG PET-CT (Figure 2) demonstrated marked metabolic activity in the left upper lobe nodule with an SUV maximum of 9.1. Metabolically active mediastinal and left hilar lymphadenopathy was also noted with an SUV maximum of 5.9.

Interestingly, increased metabolic activity of the right vocal cord compared to the left was noted on the PET scan (Figure 2B). Direct laryngoscopy, performed during intubation for a diagnostic bronchoscopy and endobronchial ultrasound, confirmed left vocal cord paralysis. EBUS sampling of multiple mediastinal hilar lymph node stations, including 4L, and 7, confirmed malignant cells compatible with small cell lung carcinoma. Immunohistochemistry further supported the diagnosis, revealing positive staining for TTF-1, synaptophysin, CD56, and focal chromogranin negativity.

The false-positive PET scan of the larynx, correlated with laryngoscopic findings, points towards contralateral vocal cord paralysis. The asymmetrical FDG uptake in the right vocal cord is attributed to compensatory muscle activation due to left vocal cord paralysis. Vocal cord paralysis is almost twice as common on the left due to the longer anatomical pathway of the left recurrent laryngeal nerve and the fact that it passes through the aortopulmonary window [1]. In this case, PET/CT images demonstrated that the focal FDG uptake was localized in the right vocal cord muscles. This focal FDG uptake is a result of increased work of vocal cord muscles caused by contralateral (left) recurrent laryngeal nerve palsy due to direct nerve invasion by the metastatic adenopathy. Knowledge of this pitfall is important to avoid false-positive PET results [2].

Abdulmonam Ali, MD

Pulmonary & Critical Care

SSM Health

Mount Vernon, IL USA

References

1. Lee M, Ramaswamy MR, Lilien DL, Nathan CO. Unilateral vocal cord paralysis causes contralateral false-positive positron emission tomography scans of the larynx. Ann Otol Rhinol Laryngol. 2005 Mar;114(3):202-6. [CrossRef] [PubMed]
2. Oner AO, Boz A, Surer Budak E, Kaplan Kurt GH. Left Vocal Cord Paralysis Detected by PET/CT in a Case of Lung Cancer. Case Rep Oncol Med. 2015;2015:617294. [CrossRef] [PubMed]

Cite as: Ali A. July 2024 Medical Image of the Month: Vocal Cord Paralysis on PET-CT. Southwest J Pulm Crit Care Sleep. 2024;29(1):6-7. doi: https://doi.org/10.13175/swjpccs012-24 PDF

May 2021 Imaging Case of the Month: A Growing Indeterminate Solitary Nodule

Joseph Jeehoon Kim, MD^°

Kenneth K. Sakata, MD^‡

Natalya Azadeh, MD, MPH^‡

Maxwell Smith, MD^↑

Michael B. Gotway, MD^†

^°Department of Medicine, Mayo Clinic Arizona

^↑Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona

^‡Division of Pulmonary and Critical Care Medicine, Mayo Clinic Arizona

^†Department of Radiology, Mayo Clinic, Arizona

5777 East Mayo Boulevard

Phoenix, Arizona 85054

A 58-year-old woman with a history of orthotopic heart transplant, performed for Adriamycin-induced cardiomyopathy, treated with mycophenolate and tacrolimus, presented for routine interval follow up. The patient’s past medical history was significant for follicular thyroid carcinoma treated with total thyroidectomy and bilateral breast carcinoma in remission as well as hypothyroidism and type II diabetes mellitus. In addition to tacrolimus and mycophenolate, the patient’s medications included aspirin, insulin, itraconazole (for anti-fungal prophylaxis), levothyroxine, prednisone (tapering since transplant), and valganciclovir. The patient recently complained of rhinorrhea and cough productive of brown-tinged sputum, improving over the previous 2 weeks; she denied fever, chills, shortness of breath, night sweats chest pain, or gastrointestinal symptoms.

Physical examination showed the patient to be afebrile with normal heart and respiratory rates and blood pressure. Her room air oxygen saturation was 99%.

The patient’s complete blood count and serum chemistries showed largely normal values, with the white blood cell count at the upper normal at 9.7 x 10⁹ /L (normal, 4-10 x 10⁹ /L). Her liver function testing and renal function testing parameters were also within normal limits. Echocardiography showed normal left ventricular systolic function. The patient underwent frontal chest radiography (Figure 1).

Figure 1. Frontal chest radiography.

Which of the following represents an appropriate interpretation of her frontal chest radiograph? (Click on the correct answer to be directed to the second of nine pages). 

1. Frontal chest radiography shows a right pleural effusion
2. Frontal chest radiograph shows a left apical nodule
3. Frontal chest radiography shows multifocal consolidation
4. Frontal chest radiography shows peribronchial and mediastinal lymphadenopathy
5. Frontal chest radiography shows cardiomegaly

Cite as: Kim JHJ, Sakata KK, Azadeh N, Smith M, Gotway MB. May 2021 Imaging Case of the Month: A Growing Indeterminate Solitary Nodule. Southwest J Pulm Crit Care Med. 2021;229(5):88-99. doi: https://doi.org/10.13175/swjpcc013-21 PDF

February 2016 Imaging Case of the Month

Michael B. Gotway, MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ

Imaging Case of the Month CME Information  

Members of the Arizona, New Mexico, Colorado and California Thoracic Societies and the Mayo Clinic are able to receive  0.25 AMA PRA Category 1 Credits™. Completion of an evaluation form is required to receive credit and a link is provided on the last panel of the activity.

0.25 AMA PRA Category 1 Credit(s)™

Estimated time to complete this activity: 0.25 hours

Lead Author(s): Michael B. Gotway, MD. All Faculty, CME Planning Committee Members, and the CME Office Reviewers have disclosed that they do not have any relevant financial relationships with commercial interests that would constitute a conflict of interest concerning this CME activity. 

Learning Objectives:
As a result of this activity I will be better able to:    

1. Correctly interpret and identify clinical practices supported by the highest quality available evidence.
2. Will be better able to establsh the optimal evaluation leading to a correct diagnosis for patients with pulmonary, critical care and sleep disorders.
3. Will improve the translation of the most current clinical information into the delivery of high quality care for patients.
4. Will integrate new treatment options in discussing available treatment alternatives for patients with pulmonary, critical care and sleep related disorders.

Learning Format: Case-based, interactive online course, including mandatory assessment questions (number of questions varies by case). Please also read the Technical Requirements.

CME Sponsor: University of Arizona College of Medicine at the Arizona Health Sciences Center.

Current Approval Period: January 1, 2015-December 31, 2016

Financial Support Received: None.

Clinical History: A 78 year-old woman presented to her physician for routine care. Her past medical history included hyperlipidemia, hypothyroidism, gout, hypertension, and arthritis.

Although she was asymptomatic, screening frontal and lateral chest radiography (Figure 1) was performed.

Figure 1. Frontal (A) and lateral (B) chest radiography.

Which of the following statements regarding the chest radiograph is most accurate? (Click on the correct answer to proceed to the second of nine panels)

1. The frontal chest radiograph shows a poorly defined nodular opacity in the left upper lung
2. The frontal chest radiograph shows abnormal mediastinal contours
3. The frontal chest radiograph shows basal predominant fibrotic abnormalities
4. The frontal chest radiograph shows large lung volumes with a cystic appearance
5. The frontal chest radiograph shows no abnormal findings

Cite as: Gotway MB. February 2016 imaging case of the month. Southwest J Pulm Crit Care. 2016;12(2):48-58. doi: http://dx.doi.org/10.13175/swjpcc014-16 PDF

May 2013 Imaging Case of the Month

Michael B. Gotway, MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ

Clinical History

A 21-year-old woman presented with complaints of cough. Frontal and lateral chest radiography (Figures 1A & B) was performed. A detail comparison chest radiograph from several years prior (Figure 1C) is presented as well.

 

Figure 1. Frontal (A) and lateral (B) chest radiography at presentation and a radiograph from several years earlier (C).

Which of the following statements regarding the chest radiograph is most accurate?

1. The chest radiograph predominantly shows bilateral linear and reticular abnormalities
2. The chest radiograph shows a combination of nodules, masses and thin-walled cysts
3. The chest radiograph shows multifocal consolidation with air bronchograms
4. The chest radiograph shows multifocal pleural abnormalities
5. The chest radiograph shows mediastinal widening & hilar lymphadenopathy

Reference as: Gotway MB. May 2013 imaging case of the month. Southwest J Pulm Crit Care.2013;6(5):218-30. PDF