Title : A case of tuberculosis masquerading as lung malignancy - A diagnostic chameleon
Abstract:
BACKGROUND:
Lung cancer and tuberculosis are frequently confused and misdiagnosed. Lung cancer and
tuberculosis share similar clinical presentation and radiological features. Hence, with
pathological and microbiological tests, the diagnosis must be verified. Here, presenting a case
of tuberculosis presenting as right upper lobe malignancy.
CASE PRESENTATION:
A 57-year-old male presented with complaints of right sided chest pain and dry cough for 10
days. He is a non-smoker and occasional alcoholic. Farmer by occupation. His chest x-ray
showed right upper zone homogenous opacity. CT chest was taken which showed right upper
lobe mass with mediastinal lymphadenopathy. His PET CT showed heterogeneously
enhancing pleural based soft tissue mass with necrotic areas and calcifications in the upper
lobe of right lung (SUVmax 11.97), multiple discrete nodular in both lung parenchyma
involving all lobes and mediastinal lymphadenopathy. In view of avid PET uptake and
radiological features, the patient was planned for image guided biopsy of the lesion.
DIAGNOSIS AND TREATMENT:
The biopsy from the right upper lobe mass reported as lung parenchyma lined by
pseudostratified columnar epithelium showing predominantly necrosis, ill defined
granulomas and Langhan type of giant cells admixed mild lymphocytic aggregates and
suggestive of caseating granulomatous lesion. And hence, patient was initiated on anti
tubercular drugs (rifampicin, isoniazid, ethambutol, pyrazinamide).
CONCLUSION:
- It can be difficult to distinguish pulmonary TB from tumour based on clinical and
radiographic symptoms. - The same radiological characteristics that are indicative of lung cancer, such as
irregularly shaped consolidations and thick-walled cavities, PET showing high
metabolic activity are also typical of lung tuberculosis. - To minimise unnecessary diagnostic procedures and delayed treatment initiation,
tuberculosis should be considered as one of the differential diagnoses for PET positive
lung infiltrate.
