Interact CardioVasc Thorac Surg 2007;6:260-261. doi:10.1510/icvts.2006.141598
© 2007 European Association of Cardio-Thoracic Surgery
Case report - Thoracic general |
Positron emission tomography staging of pleural deposits following Monaldi's procedure: an accurate reflection or a false staging?
Nael Al-Sarraf*,
Kishore Doddakula,
Trudy Wedde and
Vincent Young
Department of Cardiothoracic Surgery, St James's Hospital, Dublin 8, Ireland
Received 5 August 2006;
received in revised form 4 November 2006;
accepted 24 November 2006
*Corresponding author. Tel.: +353-1-4103389; fax: +353-1-4103700.
E-mail address: trinityq8{at}hotmail.com (N. Al-Sarraf).
 |
Abstract
|
|---|
Positron emission tomography (PET) has become widely available in staging non-small cell lung cancer (NSCLC) and despite its high accuracy, false positive staging remains a problem. We report a rare case where such false positive staging caused a dilemma in optimal management.
Key Words: Positron emission tomography; Talc; Monaldi; Non-small cell lung cancer
|
1. Case report
|
|---|
A 46-year-old man presented three years ago with dyspnoea on moderate exertion and a productive cough. He was an ex-smoker and worked as a coal miner. His initial chest radiograph revealed a giant bulla (14 cm long) occupying most of the right upper lobe. This was confirmed with high resolution CT thorax which also revealed emphysematous changes in the lung fields bilaterally and his pulmonary function tests (PFTs) showed moderate airflow obstruction. Subsequently, he underwent Monaldi's procedure for his right upper lobe bulla and had an uneventful recovery. Over the following three years, he was followed up regularly with serial chest radiographs (CXR) and PFTs. On a routine CXR obtained three months previously; there was 3.5 cm pulmonary lesion in the right upper lobe. His physical examination and routine blood tests at the time of this CXR were entirely normal. CT scan of the chest (Fig. 1) revealed a 3.5x3.7 cm mass in the posterior segment of right upper lobe associated with 1 cm AP window lymphadenopathy and 0.6 cm node in right lower paratracheal position. There was also bilateral calcified pleural thickening, more prominent on the right side, but no signs of distant metastasis in liver or adrenals. A flexible bronchoscopy showed no endobronchial lesion and CT-guided needle biopsy of the right upper lobe lesion showed moderately-differentiated NSCLC. A whole body PET-CT scan was performed to assess mediastinal nodal disease, and showed high fluorodeoxyglucose (FDG) uptake in the right upper lobe lesion with maximum standardized uptake value (SUVmax) of 14.8. This was associated with a further uptake in a right apical mass (SUVmax 15.5) and FDG uptake along the posterior pleural margin of the right lung (Figs. 1 and 2). There was also avid uptake in a large anterior pleural plaque (SUVmax of 16) in the same side. No FDG uptake was seen in the mediastinum or outside the chest. A decision was made to proceed directly to thoracotomy and intraoperative frozen sections were carried out to assess these plaques and the high uptake lesions. Surprisingly, these frozen sections were benign and we proceeded to right upper lobectomy and systematic lymph node dissection (SLND). Histology subsequently revealed moderately differentiated squamous cell carcinoma (5 cm in maximum diameter) with no lymph nodal involvement (pathological T2N0M0). Resection margins and pleural surface were free of malignancy. Interestingly, extensive deposits of talc with associated giant cell reaction were also seen corresponding to his previous Monaldi's operation. A similar appearance was also seen in the pleural plaques. The patient made an uncomplicated recovery and remained well for six months postoperatively with no signs of recurrence.
View larger version (63K):
[in this window]
[in a new window]
|
Fig. 1. Right upper lobe mass appearance on CT (left) and PET (right) showing avid uptake of FDG. Note the thickened pleura on CT.
|
|
View larger version (62K):
[in this window]
[in a new window]
|
Fig. 2. Pleural deposits visible on CT (Left) and on PET (Right). Note avid FDG uptake by pleural deposits both anteriorly and posteriorly.
|
|
|
2. Discussion
|
|---|
This case is unusual for a few reasons. Firstly, extensive pleural plaques caused by an intense inflammatory response to talc (used in Monaldi's procedure) conferring un-resectability of NSCLC have never been reported. Secondly, the high SUVmax of such talc-induced pleural plaques have never been reported to be higher than that of the corresponding primary pulmonary nodule. Finally, this case illustrates the false upstaging caused by PET as a consequence of chronic inflammation lasting three years from the time Monaldi's procedure was carried out.
Monaldi's drainage technique was initially employed for patients with giant tuberculous cavities [1] and later modified and adapted for bullous and emphysematous lung disease [2]. Briefly, this technique requires a small incision in the chest and pleura followed by an incision into the bulla and liberation of iodide talc into bulla cavity. This is followed by insertion of giant Foley's catheter into bulla cavity (and securing it with two concentric polypropylene purse string) and inflating catheter's balloon to function as a self-retaining intrapulmonary drain. Then, the remaining free pleural cavity is insufflated with talc to obtain a thorough postoperative pleurodesis. This is followed by insertion of intra-pleural drain and both of these drains are left connected to an under-water seal with negative suction for a few days [2].
Current evidence suggests that Talc alone (in its asbestos free form) is non-carcinogenic, but when exposure to talc is associated with other carcinogens (e.g. asbestos, polycyclic hydrocarbons) increased incidence of lung cancer is observed [3, 4]. This might well explain the incidence of NSCLC in our patient as he was a heavy smoker and worked as a coal miner.
Only three cases have reported the observation that Talc slurry (used in pleurodesis) can cause false positive staging by PET [5–7]. Our case illustrates the fact that Monaldi with Talc can cause false upstaging of primary NSCLC by integrated PET-CT. Our case turned out to be completely respectable with no evidence of lymph node involvement pathologically. This is the first case report that shows Monaldi's procedure (with Talc) can falsely upstage NSCLC on integrated PET-CT. In a recent study, Han Kwek et al. reported PET appearance on nine patients treated with talc pleurodesis for malignant effusion and persistent air leaks [8]. FDG uptake was either diffuse (in two cases) or focal (in seven cases) and most commonly occurred in the posterior costophrenic angles followed by apical regions and anterior chest wall and costophrenic angles. These findings correlated with high-density areas of pleural thickening on CT [8]. Our case is consistent with such an observation both from CT and PET-CT appearance.
This case illustrates an unusual presentation of talc-containing pleural plaques that mimicked pleural malignancy in a patient with a history of Monaldi. The high SUVmax of such an inflammatory reaction can be misleading for clinicians interpreting PET-CT. Such a rare association should raise the suspicion of false upstaging and should be verified histologically, as in our case, which turned out to be respectable with good long-term prognosis.
|
References
|
|---|
- O'Kelley W, Pecora DV. The Monaldi procedure: a report of thirty cases. Am Rev Tuberc 1952; 65:83–87.[Medline]
- Venn GE, Williams PR, Goldstraw P. Intracavity drainage for bullous, emphysematous lung disease: experience with the Brompton technique. Thorax 1988; 43:998–1002.[Abstract/Free Full Text]
- Wild P. Lung cancer risk and talc not containing asbestiform fibres: a review of the epidemiological evidence. Occup Environ Med 2006; 63:4–9.[Abstract/Free Full Text]
- Stenback F, Rowlands J. Role of talc and benzo(a)pyrene in respiratory tumour formation. An experimental study. Scand J Respir Dis 1978; 59:130–140.[Medline]
- Weiss N, Solomon SB. Talc pleurodesis mimics pleural metastases: differentiation with positron emission tomography/computed tomography. Clin Nucl Med 2003; 28:811–814.[CrossRef][Medline]
- Murray JG, Erasmus JJ, Bahtiarian EA, Goodman PC. Talc pleurodesis simulating pleural metastases on 18F-Fluorodeoxyglucose positron emission tomography. Am J Roentgenol 1997; 168:359–360.[Free Full Text]
- De Weerdt S, Noppen M, Everaert H, Vincken W. Positron emission tomography scintigraphy after thoracoscopic talcage. Respiration 2004; 71:284.[CrossRef][Medline]
- Han Kwek B, Aquino SL, Fischman AJ. Fluorodeoxyglucose positron emission tomography and CT after talc pleurodesis. Chest 2004; 125:2356–2360.
|
|
Top
Abstract
1. Case report