SESSION TITLE: Infectious Disease Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Association between lung cancer and pulmonary tuberculosis (TB) is not rare and it has been described since 1810. The physiopathological mechanism that links these 2 diseases is not precisely known. In a patient previously exposed to lung TB, the risk of developing lung cancer may be 11 fold higher, possible related to the TB scars, and a high secretion of epiregulin (ligand to epidermal growth factor receptor or other members from the tyrosine-kinase receptors family involved in carcinogenesis) from the cells involved in TB infection. On the other hand, a neoplastic modification could induce immunosuppression which could allow a mycobacterium infection to progress to TB disease. We present three cases of association of both active TB and lung cancer (2 of them having had previous tuberculosis, 1 new case) in order to exemplify that in the case of coexistence of these diseases the correct diagnosis might be more difficult to obtain.
CASE PRESENTATION: First case: Male, 55 years, smoker 30 pack-years, previously treated several times for pulmonary tuberculosis (abandoned therapy each time), actually in treatment since two months, brought by his family for an important deterioration of general and mental state. Bacteriological exam reveals positive smears and cultures for Mycobacterium tuberculosis (MTB), with no available drug sensibility test. Chest X-rays revealed infiltrative apical lesions and bilateral fibrous lung scars attributed to previous episodes of TB disease. As the mental state continued degrading without any obvious reason, a CT scan of brain and chest was performed and identified a right hilar lung tumor, with brain and bones metastasis. The patient died two weeks later. Second case: Male, 54 years, former smoker 45 pack-years, was admitted for consumptive syndrome, persistent cough, dyspnea, considering a relapse of pulmonary TB disease. Positive smears for acid fast bacilli were revealed and second regimen of DOTS started. Polyuria, pulmonary and neurological status occurred one week later and the lab tests showed important hypercalcaemia, with normal parathyroid hormone level. The presumptive diagnosis was humoral hypercalcaemia syndrome suggestive for malignancy, but imagistic screening of primitive cancer did not identify it. After two months of supportive therapy, the patient dies and necropsy revealed a squamous cell lung carcinoma. Third case: Male, 45 years, smoker 40 pack-years, with weight loss and persistent cough was X-ray diagnosed with a lung lower lobe nodular opacity. Fiberbronchoscopy identified an incomplete stenosis of the left lower lobar bronchia, with a granular aspect. Histological exam of bronchial biopsy sample revealed an epithelial dyskaryosis. CT scan of the chest showed a tumoral mass and left pneumectomy was performed (adenocarcinoma). One month later, positive cultures for MTB recommended the first regimen of DOTS. Evolution was good after tuberculosis treatment.
DISCUSSION: Delay in the identification of the tumor, due to diagnosis of tuberculosis, is very important, as survival in patients with lung cancer and TB is lower than in those without TB and continues to drop with every day spent without correct and complete diagnostic and specific treatment. When the presence of lung cancer is evident, this may also delay TB diagnosis, allowing the infection to evolve.
CONCLUSIONS: In a TB burden country, as Romania, not all new or readmitted cases with positive bacteriological exam for MTB are simple cases of active TB disease and also, excluding TB diagnosis after identifying a tumor without correct bacteriological investigation might be a mistake. Due to consequences of association of lung cancer and TB, all effort should be made to identify both diseases by active screening in risk population.
Reference #1: Cha SI, Shin KM, Lee JW, Lee SY, Kim CH, Park JY, Jung TH, The clinical course of respiratory tuberculosis in lung cancer patients. Int J Tuberc Lung Dis. 2009 Aug;13(8):1002-7.
Reference #2: Shieh SH, Probst JC, Sung FC, Tsai WC, Li YS, Chen CY, Decreased survival among lung cancer patients with co-morbid tuberculosis and diabetes. BMC Cancer. 2012 May 11;12:174. doi: 10.1186/1471-2407-12-174.
Reference #3: Saulius Cicenas, Vladislavas Vencevicius. Lung cancer in patients with tuberculosis. World J Surg Oncol. 2007; 5: 22.
DISCLOSURE: The following authors have nothing to disclose: Oana Deleanu, Ana-Maria Nebunoiu, Ruxandra Ulmeanu, Florin Mihaltan, Oana Arghir
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