Rheumatology Advance Access originally published online on January 25, 2006
Rheumatology 2006 45(3):359-360; doi:10.1093/rheumatology/kel006
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
LETTER TO THE EDITOR |
Bronchogenic carcinoma associated with rheumatoid arthritis: role of FDG-PET scans
Thoracic Surgery Department, 1 Pathology Department and 2 Pneumology Department, Hospital Universitario de Gran Canaria ‘Doctor Negrín’, Las Palmas de Gran Canaria, Canary Islands, Spain
Correspondence to: P. Rodríguez, Thoracic Surgery Department, Hospital Universitario de Gran Canaria ‘Dr Negrín’ C/Barranco de la Ballena s/n. 35010 Las Palmas de Gran Canaria, Canary Islands, Spain. E-mail: prosu2001{at}yahoo.es
SIR, Lung involvement occurs in 50% of patients with rheumatoid arthritis (RA). Its forms are variable, pulmonary nodules being the least frequent [1]. It is occasionally necessary to establish a differential diagnosis between rheumatoid nodules (RN) and bronchogenic carcinoma (BC), especially in smokers or immunocompromised patients [1]. There are no clinical or laboratory data to help with this differentiation and imaging techniques are not specific enough, which is why histological confirmation is recommended, either by bronchoscopy, transthoracic fine-needle aspiration (TFNA) or even surgical biopsy [2]. Positron emission tomography using 18-fluorodeoxyglucose (FDG-PET) is a non-invasive technique permitting the qualitative and semiquantitative analysis of tissue metabolic activity, which is increased in BC, and which can guide the diagnosis of a suspected malignant pulmonary nodule in a patient with RA [3, 4]. We describe two RA patients with pulmonary nodules in which FDG-PET allowed the diagnosis and staging of BC, avoiding diagnostic surgical lung biopsy.
The first case was a 64-yr-old woman, a non-smoker, diagnosed with seropositive RA in functional class I, undergoing treatment with methotrexate (7.5 mg/week). The physical examination showed mechanical pain and articulate tumefaction in the wrists and metacarpal phalanges. Chest X-ray and computed tomography (CT) revealed a nodule measuring 2.1 cm located in the upper right lobe. Bronchoscopy and TFNA were not conclusive. FDG-PET discovered abnormal increased activity corresponding to the location of the pulmonary nodule and hilar region, so BC was suspected (Fig. 1). Video-assisted thoracoscopy (VAT) biopsy of the nodule confirmed BC, so a right upper lobectomy and lymphadenectomy was performed. The definitive histology was infiltrant adenocarcinoma over an RN with mediastinal nodule involvement (T2N2M0). The postoperative course was satisfactory and the patient received adjuvant chemo-radiotherapy.
|
The second case was a 40-yr-old male, a smoker (30 cigarettes/day) diagnosed with seropositive RA in functional class II. Treatment was carried out combining methotrexate (7.5 mg/week) with leflunomide (20 mg/day). A chest X-ray and CT confirmed bilateral pulmonary nodules, one of them measuring 1.9 cm, in the left upper lobe, which bronchoscopy showed was positive for BC. FDG-PET was done to discard metastases in the rest of the nodules, and showed abnormal increased FDG activity corresponding only to BC. An upper left lobectomy and biopsies of the left lower lobe nodules were done. The definitive histology was infiltrant adenocarcinoma (T2N1M0) and the biopsies of the lower pulmonary nodules confirmed RN.
The appearance of a pulmonary nodule in a patient with RA creates a diagnostic dilemma between RN and BC [1, 5]. Pulmonary RN are found in 1% of chest X-rays and up to 20% in high-resolution CTs [2]. It is frequent in males and smokers with subcutaneous RN and positivity for rheumatoid factor [1, 2]. Its radiological characteristics are not very specific, with central cavitation in 50% of cases [2]. They are usually asymptomatic and do not require treatment, except when there are complications such as bronchopleural fistula or infection, which are present in up to 50% of cases [2]. The possibility of developing BC in patients with RA is higher than in the general population, and the most important aetiopathogenic theories are autoimmune alterations and immunosuppressor treatment with methotrexate [1]. In RA patients, the most frequent BC histological types are adenocarcinoma and bronchoalveolar carcinoma [2]. BC growth over a pulmonary RN, as in our second case, is an exceptional occurrence that has been described only three times in the literature [1]. The accuracy of CT in diagnosing BC is approximately 78%, which in most cases makes histological confirmation necessary for definitive diagnosis [6]. Bronchoscopy is recommended in central nodules, with an accuracy of 80%, and TFNA is the choice for peripheral nodules, with 86% effectiveness [7]. When these methods fail, a VAT biopsy is recommended, which allows histological confirmation in 100% of cases, with a morbidity of 9.6% and mortality of 0.5% [5, 8]. The diagnostic sensitivity of FDG-PET in malignant nodules varies between 96.8 and 100% and specificity varies between 77.8 and 88%; the positive predictive value is 94% and the negative predictive value is 100% [3]. The main false positives are inflammatory or infectious lesions, and the main false negatives are nodules smaller than 1 cm and well-differentiated or slow-growing carcinomas [3, 9]. A positive FDG-PET for malignancy always requires surgical excision of the nodule in order to obtain histological confirmation. If FDG-PET is negative, patient follow-up can be established with CT, bronchoscopy, TFNA or FDG-PET, mainly in patients with high surgical risk [10]. In patients with confirmed BC and pulmonary nodules, FDG-PET contributes to the establishment of a differential diagnosis between RN and metastases, as occurred in one of our cases. We have found no reports comparing FDG-PET and VAT in the management of pulmonary nodules. We conclude that FDG-PET is a technique with high diagnostic accuracy, and can be used before surgical biopsy in patients with RA and pulmonary nodules who are suspected of having BC.
The authors have declared no conflict of interest.
References
- Baruch AC, Steinbronn K, Sobonya R. Pulmonary adenocarcinomas associated with rheumatoid nodules: a case report and review of the literature. Arch Pathol Lab Med 2005;129:104–6.[Medline]
- Scully RE, Mark EJ, Shepard JO, Ebeling SH, Ellender SM, Peters CC. Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 10-2001. A 53-year-old woman with arthritis and pulmonary nodules. N Engl J Med 2001;344:997–1004.
[Free Full Text] - Gould MK, Maclean CC, Kuschner WG, Rydzak CE, Owens DK. Accuracy of positron emission tomography for diagnosis of pulmonary nodules and mass: a meta-analysis. JAMA 2001;285:914–24.
[Abstract/Free Full Text] - Dewan NA, Reeb SD, Gupta NC, Gobar LS, Scott WJ. PET-FDG imaging and transthoracic needle lung aspiration biopsy in evaluation of pulmonary lesions comparative risk benefit analysis. Chest 1995;108:441–6.
[Abstract/Free Full Text] - Laloux L, Chevalier X, Maitre B et al. Unusual onset of rheumatoid arthritis with diffuse pulmonary nodulosis: a diagnostic problem. J Rheumatol 1999;26:920–2.[Medline]
- Burns J, Haramati LB, Whitney K, Zelefsky MN. Consistency of reporting basic characteristics of lung nodules and masses on computed tomography. Acad Radiol 2004;1:233–7.
- Ohno Y, Hatabu H, Takenaka D et al. CT-guided transthoracic needle aspiration biopsy of small (< or = 20 mm) solitary pulmonary nodules. Am J Roentgenol 2003;180:1665–9.
[Abstract/Free Full Text] - Jimenez MF, Spanish Video-Assisted Thoracic Surgery Study Group. Prospective study on video-assisted thoracoscopic surgery in the resection of pulmonary nodules: 209 cases from the Spanish Video-Assisted Thoracic Surgery Group. Eur J Cardiothorac Surg 2001;19:562–5.
[Abstract/Free Full Text] - Nomori H, Watanabe K, Ohtsuka T, Naruke T, Suemasu K, Uno K. Evaluation of F-18 fluorodeoxyglucose (FDG) PET scanning for pulmonary nodules than 3 cm in diameter, with special reference to the CT images. Lung Cancer 2004;45:19–27.[CrossRef][ISI][Medline]
- Sortini D, Maravegias K, Feo CV, Sortini A. Repeat needle biopsies combined with clinical observation are safe and accurate in the management of a solitary pulmonary nodule. Cancer 2005;103:599–607.[CrossRef][ISI][Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||