Pulmonary tuberculosis presenting as mass lesions and simulating neoplasms in adults

Pseudotumoural pulmonary tuberculosis: a case series

This report describes three cases of tumour-like pulmonary tuberculosis: two patients had stage C3 human immunodeficiency virus (HIV) infection (with uncontrolled HIV-1 in one case) and one patient was immunocompetent. All patients initially presented with general and respiratory symptoms, with radiological findings simulating lung carcinoma. Tuberculosis was diagnosed from microbiological testing and/or histological examination results. A disseminated form was described in one case. All patients were treated successfully with antimycobacterial therapy, with control of HIV infection in both cases.

Tuberculosis Diagnostics and Localization in Chest X-Rays via Deep Learning Models

For decades, tuberculosis (TB), a potentially serious infectious lung disease, continues to be a leading cause of worldwide death. Proven to be conveniently efficient and cost-effective, chest X-ray (CXR) has become the preliminary medical imaging tool for detecting TB. Arguably, the quality of TB diagnosis will improve vastly with automated CXRs for TB detection and the localization of suspected areas, which may manifest TB. The current line of research aims to develop an efficient computer-aided detection system that will support doctors (and radiologists) to become well-informed when making TB diagnosis from patients' CXRs. Here, an integrated process to improve TB diagnostics via convolutional neural networks (CNNs) and localization in CXRs via deep-learning models is proposed. Three key steps in the TB diagnostics process include (a) modifying CNN model structures, (b) model fine-tuning via artificial bee colony algorithm, and (c) the implementation of linear average–based ensemble method. Comparisons of the overall performance are made across all three steps among the experimented deep CNN models on two publicly available CXR datasets, namely, the Shenzhen Hospital CXR dataset and the National Institutes of Health CXR dataset. Validated performance includes detecting CXR abnormalities and differentiating among seven TB-related manifestations (consolidation, effusion, fibrosis, infiltration, mass, nodule, and pleural thickening). Importantly, class activation mapping is employed to inform a visual interpretation of the diagnostic result by localizing the detected lung abnormality manifestation on CXR. Compared to the state-of-the-art, the resulting approach showcases an outstanding performance both in the lung abnormality detection and the specific TB-related manifestation diagnosis vis-à-vis the localization in CXRs.

Reactivation of Pulmonary Tuberculosis in Malignancy

Aims and Background

Deterioration of immunity due to local or systemic effects of the tumor itself and/or administered chemotherapeutics or radiotherapy may play roles in the reactivation of tuberculosis, increasing the mortality in patients with various malignancies. In a country with a high prevalence of tuberculosis such as Turkey, most people have inactive tuberculous lesions and tuberculin test positivity. Therefore, a prospective study was carried out to investigate the frequency of tuberculosis reactivation in patients with a malignancy.

Methods

Seventy-three patients with a malignancy and undergoing diagnostic fiberoptic bronchoscopy were enrolled in the study during a 2-year period (1993-1995). Bronchoscopic biopsies and cytologic materials were obtained. Bronchoalveolar lavage fluids, bronchial washings, and pre- and post-bronchoscopic sputum specimens were also evaluated for acid-fast bacilli. A diagnosis of tuberculosis was based on smear and/or culture positivity for acid-fast bacilli.

Results

The mean age of the patients was 56.2 ± 13.6 years, with a male/female ratio of 69/4. The biopsy proven malignancies were as follows: primary lung carcinoma (n = 66, 90.4%), lymphoma (n = 5, 6.8%), metastatic breast adenocarcinoma (n = 1, 1.4%), and acute myelocytic leukemia (n = 1, 1.4%). Thirty-one of all patients had findings compatible with tuberculosis on radiology. The sputa and bronchial washing specimens were smear negative in all patients. Acid-fast bacilli were grown on culture in 6 patients (8%) (primary lung cancer, n = 5; non-Hodgkin lymphoma, n = 1). Four of these 6 patients had positive radiology for tuberculosis. These subjects were treated with a three- or four-drug anti-tuberculosis regimen. Two months later, smears remained acid-fast bacilli negative, or no bacilli were grown on culture.

Conclusions

The possibility of coexisting tuberculosis should be kept in mind in patients with a malignancy, especially those with lung carcinoma in countries with a high prevalence of tuberculosis. Pulmonary infections encountered in such patients should raise the suspicion of tuberculosis reactivation, and in addition to direct microscopic evaluation, sputum specimens and materials obtained by fiberoptic bronchoscopy should be cultivated for tuberculosis. Three-four-drug anti-tuberculosis regimens should be given, especially in countries with high drug-resistance rates for eradicating tuberculosis.

[Tuberculous pseudotumour, a challenging diagnosis]

INTRODUCTION

The pseudotumorous form of tuberculosis is a rare entity. Whatever its location, it can simulate neoplasia by its radiological and/or endoscopic appearances. We highlight the diagnostic difficulties associated with this type of presentation.

METHODS

We performed a retrospective study of inpatient records from 2003 to 2016 in the pneumology department of La Rabta Hospital to identify cases of thoracic tuberculous pseudo-tumor.

RESULTS

Seventeen patients were identified. The median age was 41 years and their symptomatology was dominated by cough and general debility. All had abnormal radiology with 10 cases of suspect lesions. Fibre-optic bronchoscopy revealed endobronchial abnormalities in 11 cases. The median overall diagnostic delay was 97 days. The diagnosis was confirmed bacteriologically in five cases, histologically in 14 cases and based on clinical presumption in one case. The progression was favourable: 13 patients have been declared cured and four patients are still undergoing treatment.

CONCLUSION

Making a positive diagnosis of thoracic tuberculous pseudotumour can be difficult, as bacteriological samples are often negative. This can lead to a significant delay in diagnosis and treatment.

[Diagnostic difficulty in bronchopulmonary tuberculous pseudotumor]

Pseudotumour is a rare presentation of bronchopulmonary tuberculosis, occurring in immunocompetent patients, which simulates lung cancer and may thus cause diagnostic difficulty. To assess the frequency and clinical features of tuberculous pseudotumour in immunocompetent patients, we analyzed all cases of pulmonary tuberculosis hospitalized in our department. Tuberculous pseudotumour was defined by the presence of a bronchial or pulmonary lesion suggestive of lung cancer. Over a period of 11 years, 12 cases of tuberculous pseudotumour were collected among 341 cases of pulmonary tuberculosis (3.5%). Mean age was 45 years. All patients were smokers. Symptoms were not specific and were dominated by cough and chest pain. Radiological investigations showed consolidation in five cases and a mass lesion in five cases. Fibreoptic bronchoscopy visualized a tumour in four cases and stenosing bronchial wall infiltration in one case. Mean delay to diagnosis was 47 days. The confirmation of tuberculosis was bacteriologic in only three cases but histological in the others (four bronchial biopsies, two transbronchial biopsies, one pleural biopsy, four surgical specimen). The positive diagnosis of tuberculous pseudotumour is difficult because the clinical and radiological presentation may closely mimic lung cancer, especially as the cases are usually smear negative, leading to a very late diagnosis.

Parenchymal pseudotumoral tuberculosis: case series and systematic review of literature

Tuberculosis is a rampant infectious pandemic worldwide, with an annual incidence of 8 million active cases and 2 million deaths. Tuberculosis is also among the leading causes of solitary pulmonary nodule in the tropics. Although lymph nodal masses are common in tuberculosis, parenchymal masses are distinctly rare. We report eight immunocompetent adults admitted with large pulmonary masses, and ultimately diagnosed to have parenchymal pseudotumoral tuberculosis. Clinical and radiological resolution followed anti-tubercular therapy alone. We have also conducted a MEDLINE search and summarize the clinical features of all patients with parenchymal pseudotumoral tuberculosis. We also compare our findings with published literature and discuss the possible mechanisms leading to large inflammatory masses, clinical and radiologic clues to the same, common errors in clinical decision making and the therapy of this rare entity.

[CT features of pseudotumoral bronchopulmonary tuberculosis]

Pulmonary tuberculosis may at times simulate lung carcinoma on bronchoscopic examination or imaging studies. Diagnosis can be delayed and lead to surgical resection. Based on a review of 25 cases, the different CT features are reviewed.