TB MASQUERADING AS LUNG MALIGNANCY

Abstract

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Radiological manifestations of pulmonary tuberculosis (TB) tend to be heterogeneous. [1] In this report, we highlight one such atypical manifestation that posed a diagnostic dilemma and necessitated a biopsy. CASE PRESENTATION: A 67 year old male with no known medical illness presented with a 3 month history of dry cough to a hospital in southern India. The cough was associated with night sweats, appetite loss, fatigue and intermittent fever. He reported no episodes of breathlessness or hemoptysis. He denied any sick contacts, was a non smoker and had no family history of malignancy. On examination, his vital signs were stable and he was not in respiratory distress. There were no palpable lymph nodes Cardiopulmonary examination revealed no abnormal findings. Blood examination showed hemoglobin of 11.9 g/dL and ESR of 54 mm/hr, with normal blood cell counts. Chest radiograph revealed opacities in the right middle zone. A high resolution computed tomography (HRCT) of the thorax was done, and findings raised suspicion of neoplastic changes.HRCT revealed a patchy consolidation with necrotic areas and irregular margins in the superior segment of the right lower lobe, extending up to the costal pleura. Multiple ground glass opacities with nodular thickening of the oblique fissure were noted in the right lower lobe as well. Due to their typical appearance, these features were attributed to a neoplastic etiology. Interestingly, a homogenously enhancing lobulated mass was noted in the prevascular compartment of the superior mediastinum. It was also seen abutting the SVC posteriorly, where it caused a focal compression on the left brachiocephalic vein. This was thought to be a lymph nodal mass. Computed Tomography (CT) guided biopsy of the right lower lobe lesion was conducted. Histopathology revealed granulomatous inflammation with epitheloid and giant cells surrounding areas of caseous necrosis. The patient was started on Anti Tuberculous Treatment and responded well. Follow up imaging six months later revealed fibrotic changes with calcified granulomas. DISCUSSION: Clinical and radiological manifestations of TB are heterogeneous and include a variety of benign and malignant diseases. [1] Diagnostic dilemmas can delay appropriate treatment, favoring Mycobacterium tuberculosis transmission. Up to one third of TB cases have an atypical appearance on radiograph or CT imaging. [2] Thus, despite demographic features and symptoms typical of TB, our patient's HRCT posed a diagnostic dilemma. The consolidation with necrotic areas and superior mediastinal mass raised suspicion for lung malignancy. CONCLUSIONS: An extensive workup is required to differentiate TB from lung malignancy. HRCT and biopsy can be critical. Comprehensive awareness and knowledge of atypical TB manifestations can help in early diagnosis and start of therapy, increasing the probability of clinical and microbiological cure. REFERENCE #1: Collu C, Fois A, Crivelli P, Tidore G, Fozza C, Sotgiu G, Pirina P. A case-report of a pulmonary tuberculosis with lymphadenopathy mimicking a lymphoma. Int J Infect Dis. 2018 May;70:38-41. doi: 10.1016/j.ijid.2018.02.011. Epub 2018 Mar 1. PMID: 29477363. REFERENCE #2: Jeon KN, Bae K, Park MJ. Atypical radiologic appearances of pulmonarytuberculosis in non-HIV adult patients. In Proceedings: The RoyalAustralian and New Zealand College of Radiologists (RANZCR) 63rdAnnual Scientific Meeting, and Asian Oceanian Congress of Radiology(AOCR), 30 August–2 September 2012, Sydney, Australia;http://dx.doi.org/10.1594/ranzcraocr2012/R-0200 DISCLOSURES: No relevant relationships by Arup Ganguly, source=Web Response No relevant relationships by Vinayak Jain, source=Web Response No relevant relationships by Adithya Shetty, source=Web Response