PET Positive Pleural Plaques Decades after Pleurodesis: Mesolthelioma?

Ellen A. Middleton¹

Jonathan C. Daniel²

Kenneth S. Knox¹

Kathleen Williams¹

Departments of Medicine¹ and Surgery², University of Arizona College of Medicine, Tucson, AZ

Reference as: Middleton EA, Daniel JC, Know KS, Williams K.  PET positive pleural plaques decades after pleurodesis: mesolthelioma? Southwest J Pulm Crit Care 2011;2:9-16. (Click here for PDF version)

Abstract 

   A 59-year-old patient was evaluated for abnormal chest CT and hypermetabolic pleural foci on FDG-PET scan. The scans were obtained as routine surveillance for resection of an in situ pancreatic tumor.  The patient had a remote history of automobile manufacturing and the abnormalities were suggestive of asbestos exposure.  Because hypermetabolic areas were concerning for pleural malignancy, a VATS lung biopsy was performed and revealed chronic talc-induced pleuritis. The patient had a history of pnemothoraces with bilateral talc pleurodesis at the age of 16. As cancer screening and surveillance increasingly relies on extensive imaging modalities, physicians should be aware of the chronic complications of talc pleurodesis and the possibility of false positive imaging tests.

Background 

   The treatment of primary spontaneous pneumothorax (PSP) varies greatly among physicians. Treatment options include observation, chest tube decompression, simple catheter aspiration, medical thoracoscopy with pleurodesis, and surgical intervention. Talc pleurodesis is often performed as part of the intervention and although both safe and effective, the long term complications of talc exposure are not well defined. Specifically, no documented cases of pleural malignancy after instillation of talc exist. We report a patient with increased pleural activity on 18-fluorodeoxyglucose positron-emission tomography (FDG-PET) mimicking mesothelioma which ultimately proved to be chronic talc-induced pleuritis decades after pleurodesis for PSP. Biopsy and definitive diagnosis via video assisted thoracoscopic surgery (VATS) changed the course of care for this patient.

Case Report

   The patient is a 59-year-old man with past medical history significant for pancreatic adenocarcinoma in situ status post Whipple procedure in January 2009. His follow up radiologic examination revealed calcified pleural-based nodules on his CT scan. The concern for malignant mesothelioma arose, particularly as he had a history of asbestos exposure while working with automobile manufacturing in his youth.

   The patient was referred to the thoracic surgery service for evaluation. FDG-PET scan was performed and pleural nodules with a maximum SUV of 13.1 were noted (Fig 1).

Figure 1. FDG-PET and CT showing bilateral pleural nodules.

    Pulmonary function testing revealed a mild restrictive ventilatory defect.  VATS was performed and the patient underwent left thoracoscopic lysis of adhesions, pleural biopsy, and wedge resections of pleural plaques adhesed to the lung. Frozen section intra-operatively was consistent with talc crystals and fibrosis. Pathologic examination later confirmed chronic pleuritis due to talc extending into lung parenchyma without evidence of granuloma, malignancy, or presence of ferruginous bodies (Fig. 2).

 

Figure 2. The patient’s biopsy specimen showing inflammation and polarizable birefringent crystals consistent with talc.

Discussion 

   Treatment of PSP with talc pleurodesis is an effective and relatively safe means of preventing recurrence. Both acute and long-term adverse effects of talc pleurodesis are few. In our patient, the FDG-PET scan was highly suspicious for malignancy and mesothelioma. A study following patients from 14 to 40 years after pleurodesis for PSP did not shown evidence of mesothelioma or increased incidence of lung cancer (1). Lange et al. (2) demonstrated that greater than two decades post pleurodesis a large percentage of patients have pleural thickening demonstrated by plain chest x-ray and this may lead to mild restrictive impairment. In the era of the FDG-PET scan, a diagnostic dilemma is emerging as it appears many of these changes can manifest as chronic inflammatory lesions with increased metabolic activity.

    Recent case reports have documented talc related pulmonary processes that appeared malignant by FDG-PET. Tenconi et al. (3) documented a case in which a patient was experiencing cough, chest pain, and weight loss associated with hypermetabolic (SUV 4.8) pleural plaques by FDG-PET scan. The patient underwent thoracotomy and total pleurectomy revealing talc pleural granulomas from a pleurodesis 42 years prior. The authors concluded that the treatment of choice for PSP should be VATS blebectomy and pleural scarring. Similarly, Ahmadzadehfar and colleagues (4) presented a patient with pleural, mediastinal, and intrapulmonary lesions demonstrating high glucose uptake on FDG-PET imaging five years following talc pleurodesis. The pathology was consistent with talc granulomatosis.

   FDG-PET is commonly used in the diagnosis of pulmonary nodules and staging of lung cancer. It is emerging as an imaging modality in the diagnosis and management of malignant mesothelioma. The International Mesothelioma Interest Group’s consensus statement states FDG-PET is an accurate and reliable tool to differentiate malignant and benign pleural lesions. The group made the recommendation that one must exercise caution when interpreting surveillance images from patients with talc pleurodesis in the setting of mesothelioma as those patients demonstrate higher average SUV (5). No mention is made of the patient that has the radiographic appearance of mesothelioma, but histologically has talc related lesions.

    Two case series have examined the progression of pleural involvement in cancer patients following pleurodesis for malignant effusion or postthoracotomy air leak.  Nguyen and colleagues (6) performed serial FDG-PET scans between 1 month and 58 months. SUV values ranged from 1.9 to 12.6 and it was concluded that FDG uptake may persist or increase over time in chronic inflammatory plaques. Kwek et al. (7) similarly evaluated patients between 10 days and 71 months after pleurodesis and found an SUV range from 2.0 to 16.3. One patient was found to have a new area of contralateral increased FDG uptake representing pleural metastasis. The authors concluded that talc deposits can lead to false positive FDG-PET scan but it is essential to monitor stability of hypermetabolic foci.  

Conclusion

   As the population ages, the medical community can expect to see an increased number of patients who underwent talc pleurodesis decades previously. The utility of FDG-PET imaging to define malignant disease is likely limited in patients whose history includes talc pleurodesis. Physicians must be aware of the  pitfalls of emerging radiologic modalities Documented reports of FDG-PET false positives for pleural malignancy include asbestos reaction, pleurisy, recent surgery, radiotherapy, and pleural effusion secondary to inflammatory processes (7). Review of prior CT scans to evaluate the progression or stability of pleural plaques is essential. False-positive results can be devastating to patients, and often lead to invasive procedures.

References

1. Chappell AG, Johnson A, Charles J. A survey of the long-term effects of talc and kaolin pleurodesis. British journal of diseases of the chest. 1979; 73:285-288.
2. Lange P, Mortensen J, Groth S. Lung function 22-35 years after treatment of idiopathic spontaneous pneumothorax with talc poudrage or simple drainage. Thorax. 1988 Jul; 43:559-61.
3. Tenconi S, Luzzi L, Paladini P, Voltolini L, Gallazzi MS, Granato F, Gotti G. Pleural granuloma mimicking malignancy 42 years after slurry talc injection for primary spontaneous pneumothorax. Eur Surg Res. 2010; 44:201-3.
4. Ahmadzadehfar H, Palmedo H, Strunk H, Biersack HJ, Habibi E, Ezziddin S. False positive 18F-FDG-PET/CT in a patient after talc pleurodesis. Lung Cancer. 2007; 58:418-21.
5.  Nowak AK, Armato SG 3rd, Ceresoli GL, Yildirim H, Francis RJ. Imaging in pleural mesothelioma: A review of imaging research presented at the 9th international meeting of the International Mesothelioma Interest Group. Lung Cancer. 2010;70:1-6.
6.  Nguyen NC, Tran I, Hueser CN, Oliver D, Farghaly HR, Osman MM. F-18 FDG PET/CT characterization of talc pleurodesis-induced pleural changes over time:a retrospective study. Clin Nucl Med. 2009 Dec; 34 (12) :886-90. 
7. Kwek BH, AquinoSL, Fischman AJ. Fluorodeoxyglucose positron emission tomography and CT after talc pleurodesis. Chest. 2004;125:2356-60.

Corresponding author:

      Kathleen Williams, DO

      Assistant Professor of Medicine

      Pulmonary Critical Care Division

      1501 N Campbell Ave

      Tucson, AZ 85724-5030

      Tel: (520) 626-6114 Fax: (520) 626-6970

Author Contributions:

      - Acquisition of data: Dr. Daniel

      - Drafting of the manuscript: Dr. Middleton 

      - Critical revision of the manuscript for important intellectual content: Drs. Middleton, Knox, and Williams.

Abbreviation List:

      CT- Computed tomography

      FDG-PET- Positron-emission tomography with 18-fluorodeoxyglucose

      PSP- Primary spontaneous pneumothorax

      VATS - Video-assisted thoracoscopic surgery

The Development of Glossopharyngeal Breathing and Palatal Myoclonus in a 29 Year Old after Scuba Diving

Cristian Jivcu, MD

Manoj Mathew, MD

David M Baratz, MD

Allen R Thomas, MD 

Banner Good Samaritan and Phoenix VA Medical Centers

Phoenix, AZ

Reference as: Jivcu C, Mathew M, Baratz DM, Thomas AR. The development of glossopharyngeal breathing and palatal myoclonus in a 29 year old after scuba diving. Southwest J Pulm Crit Care 2011;2:3-6. (Click here for PDF version)

Introduction

   Palatal myoclonus is a rare movement disorder characterized by brief, rhythmic involuntary movements of the soft palate.  Palatal myoclonus is further subdivided into “essential palatal tremor” (EPT) and “symptomatic palatal tremor” (SPT).  EPT is characterized by involvement of the tensor veli palatini, myoclonus that might persist during sleep, as well as ear clicks, usually the patient’s presenting complaint.  The MRI and neurological exam are normal in EPT.  SPT is characterized by involvement of the levator veli palatini and myoclonus which consistently perseveres during sleep.  The MRI shows olivary hypertrophy and clinical features may include ataxia, dysarthria and nystagmus, depending on the size of the lesion¹.  Glossopharyngeal breathing is a technique used by deep-sea divers to increase lung vital capacity, which is also useful in patients with ventilator dependence from poliomyelitis and Duchenne muscular dystrophy.  To date there have been no reported cases of palatal myoclonus and glossopharyngeal breathing occurring simultaneously.  We present the case of a 29 year-old female with palatal myoclonus and glossopharyngeal breathing after scuba-diving.

Case Presentation

   A 29 year-old female presented to her physician with complaints of fevers, chills, rapid shallow breathing, ear clicks and inspiratory “spasms of the neck.” The symptoms started three days after a week-long scuba-diving trip.  She reported a total of four consecutive and uneventful dives no deeper than 50 feet.  Her descents and ascents were well-controlled.  On initial presentation she was ruled-out for pulmonary embolism and was discharged home.  Two months after first presentation she was referred to our office with persistent symptoms of ear clicks, intermittent headaches and neck spasms.  The headaches were bilateral, starting in the occipital region, radiated frontally to the eyes and felt “like a hang-over.”  The neck spasms which initially occurred with a frequency of one with every breath had decreased to one spasm every 2-3 breaths (click here for video-requires Quiktime).  Symptoms of dyspnea, wheezing, cough were absent and the rest of her medical history, including a psychiatric history, was unremarkable. Her vital signs showed a blood pressure of 110/76; Heart rate of 85 beats per minute; Temperature of 99F; Respiratory Rate of 16, and oxygen saturation of 100% while breathing room air.  On exam palatal tremor was noted with every breath, and glossopharyngeal breathing occurred every 1-2 breaths. Cranial nerves II – XII were intact and no difficulty was noted with swallowing or speaking.  Her strength was 5/5 in bilateral upper and lower extremities, and her biceps, brachioradialis and patellar reflexes were normal (+2).  Her gait was normal.  The rest of the physical exam was normal.  Her workup included a normal chest X-ray and a normal MRI of the brain. Notably absent in the brain MRI was olivary hypertrophy.  She was started on clonazepam for palatal myoclonus and neck spasms which were consistent with glossopharyngeal breathing.   After one week of administration the patient reported symptomatic improvement.  By week 2 the palatal myoclonus and glossopharyngeal breathing had completely resolved.

Discussion

   Glossopharyngeal breathing was first noted in 1951 when a respirator-dependent poliomyelitis patient with a paralyzed diaphragm was noted to be “gulping air” and increased his vital capacity from 250cc to 600cc ².  In our case the glossopharyngeal breathing was unintentional, and occurred after a scuba-diving trip.  There are no reported cases of this entity in the medical literature.  Furthermore there have been no reported cases of symptomatic palatal tremor in the setting of glossopharyngeal breathing.  A possible explanation of this co-existent entity can be found through anatomic relationships.  The glossopharyngeal nerve is involved in the movements used in glossopharyngeal breathing.  This nerve also sends a branch to the pharyngeal plexus, which in turn innervates the levator veli palatini, the muscles involved in SPT.  An overstimulation of the glossopharyngeal nerve could theoretically result in glossopharyngeal breathing as well as palatal myoclonus.

Summary

   Palatal myoclonus and glossopharyngeal breathing are usually two unrelated clinical findings.  Our conclusion is that an overstimulation of the glossopharyngeal nerve through inadvertent air-gulping during scuba-diving resulted in symptomatic palatal tremor and unintentional glossopharyngeal breathing.  Treatment with benzodiazepines resulted in complete symptom resolution.

References

1. Zadikoff C, Lang AE. Kelin C.  The ‘essentials’ of essential palatal tremor: a reappraisal of the nosology.  Brain. 2006;129:832-840.
2. Dail CW. "Glossopharyngeal breathing" by paralyzed patients: a preliminary report. Cal Med 1951;75:15-25.
3. Bach JR. Bianchi C. Vidigal-Lopes M. Turi S. Felisari G. Lung inflation by glossopharyngeal breathing and "air stacking" in Duchenne muscular dystrophy. American Journal of Physical Medicine & Rehabilitation. 86(4):295-300, 2007 Apr.
4. Bianchi C. Grandi M. Felisari G. Efficacy of glossopharyngeal breathing for a ventilator-dependent, high-level tetraplegic patient after cervical cord tumor resection and tracheotomy.  American Journal of Physical Medicine & Rehabilitation 2004;83:216-9.