Endobronchial Silicosis and Tuberculosis Presenting as the Right Middle Lobe Syndrome

Silico-Tuberculosis Mimicking Malignancy

Silico-tuberculosis is the combination of silicosis and tuberculosis (TB). Symptoms of TB such as dyspnea, cough, and hemoptysis may precede the diagnosis of an endo-bronchial mass lesion on chest imaging. Among workers who were exposed to silica, TB was more common, and experiments indicated that silica inhibits alveolar macrophage activity and severe exposure induces apoptosis. Endobronchial neoplasms, which are tumors primarily affecting the bronchial lumen, are uncommon and may show up in a wide variety of different ways pathologically. Cough, chest discomfort, wheezing, hemoptysis, recurrent pneumonia, and weight loss are common complaints from people with endobronchial tumors. The requirement for additional bronchoscopy and imaging examination is raised when symptoms such as hemoptysis and obstructive pneumonia are present. Endobronchial silicosis lesions are uncommon and develop as a result of broncho lithiasis, the endoluminal erosion of peri bronchial adenopathy, or local bronchial wall silica-induced fibrosis. Endobronchial TB can present in a varied manner, diagnosis is often challenging as there is no specific radiological feature, and sputum acid-fast bacilli several times come out negative. However, a bronchoscopy with or without biopsy is a useful investigation in these cases. The following case is a rare manifestation of endobronchial TB as it mimicked malignancy, describing the difficulties in diagnosis and treating a patient who had both silicosis and endobronchial TB.

A Complex Case of Pulmonary Silico-Tuberculosis and Review of Literature

Silicosis caused by the inhalation/deposition of free silica particles is characterized by pulmonary inflammation/fibrosis. Among the clinical disorders associated with silicosis, tuberculosis is by far the most prominent. A 66-year-old male non-smoker, originally from North Africa, reported a dry cough and significant weight loss. He was a foundry worker. He had a medical history of bladder carcinoma associated with schistosomiasis. Computed tomography (CT) and positron emission tomography (PET)/CT showed bilateral multiple hypermetabolic lung nodules, some with cavitation. The patient underwent surgical resection of the largest nodule, which was highly suspicious of lung metastasis. The histological examination revealed multiple nodular formations. Several lesions showed the characteristic features of silicotic nodules. There were also adjacent well-formed granulomas, some with central caseous necrosis. A real-time polymerase chain reaction, performed for the identification and quantification of the DNA of the Mycobacterium tuberculosis complex, was positive. Pulmonary silico-tuberculosis is often encountered in patients with a history of silica exposure in tuberculosis-endemic areas. This case serves as a reminder to never underestimate patient occupational exposure and geographic origin. A careful histological diagnosis and molecular investigation are mandatory when approaching difficult cases, especially patients with a prior cancer history and clinical/radiological features suggestive of tumour recurrence/metastasis.

Middle Lobe Syndrome in Silicosis

A case of silicosis presenting as middle lobe syndrome is described in a middle-aged female. The diagnosis was confirmed by both bronchoscopy and demonstration of right middle lobe lumen narrowing and compression by calcified hilar lymph nodes on computerized tomographic scan. Simultaneous occurrence of endobronchial silicosis and bronchial stenosis by enlarged calcified peribronchial lymph nodes causing middle lobe syndrome has not been described previously as reported in this case.

A 76-Year-Old Woman With Incidental Right Middle Lobe Atelectasis

CASE PRESENTATION

A 76-year-old nonsmoking woman visiting from Honduras for the last 6 months with no known medical history originally presented to the ED complaining of abdominal pain. While in the ED, an incidental right middle lobe collapse was found on CT abdomen scan. Review of systems was positive for a chronic productive cough with white sputum for 3 years. She denied association with fevers, chills, night sweats, hemoptysis, appetite changes, or weight loss.