Pneumoconiosis Mimicking Lung Cancer with Metastasis in Positron Emission Tomography-A Case Report

Abstract

Coal dust inhalation can result in industrial bronchitis and coal workers' pneumoconiosis (CWP), presenting as either simple pneumoconiosis or complicated CWP. With prolonged excessive exposure, small opacities in simple pneumoconiosis may coalesce and form larger opacities, recognized as progressive massive fibrosis (PMF) greater than 1 cm in diameter on chest roentgenography. Even though the degree of respiratory impairment or the presence of symptoms does not always correlate well with the extent of PMF, most workers frequently describe dyspnea, cough, and sputum production. This may be caused by a deviation in the prominent area of coalescence, the loss of upper zone lung volume, the elevation of the hila, and basilar emphysema. We present the case of a patient with an absence of occupational exposure history, who presented with a large opacity in pneumoconiosis that had a rapid onset of symptoms with dyspnea, and caused a diagnostic dilemma in attempting to distinguish a primary or metastatic neoplasm from an unusual presentation of PMF. Limited data on the PET appearance of pneumoconiosis has been reported. Whereas PET imaging may be useful in distinguishing benign from malignant disease, its role in the diagnosis of malignancy in the setting of pneumoconiosis with possible superimposed granulomatous infection remains unclear. With these considerations in mind, a PET scan was performed for this patient. Unfortunately, the PET scan could not distinguish between the possible diagnoses. Surgical intervention was arranged and the pathologic result proved pneumoconiosis.