Identification of rounded atelectasis in workers exposed to asbestos by contrast helical computed tomography

Abstract

Rounded atelectasis (RA) is a benign and unusual form of subpleural lung collapse that has been described mostly in asbestos-exposed workers. This form of atelectasis manifests as a lung nodule and can be confused with bronchogenic carcinoma upon conventional radiologic examination. The objective of the present study was to evaluate the variation in contrast uptake in computed tomography for the identification of asbestos-related RA in Brazil. Between January 1998 and December 2000, high-resolution computed tomography (HRCT) was performed in 1658 asbestos-exposed workers. The diagnosis was made in nine patients based on a history of prior asbestos exposure, the presence of characteristic (HRCT) findings and lesions unchanged in size over 2 years or more. In three of them the diagnosis was confirmed during surgery. The dynamic contrast enhancement study was modified to evaluate nodules and pulmonary masses. All nine patients with RA received iodide contrast according to weight. The average enhancement after iodide contrast was infused, reported as Hounsfield units (HU), increased from 62.5 ± 9.7 to 125.4 ± 20.7 (P < 0.05), with a mean enhancement of 62.5 ± 19.7 (range 40 to 89) and with a uniform dense opacification. In conclusion, in this study all patients with RA showed contrast enhancement with uniform dense opacification. The main clinical implication of this finding is that this procedure does not permit differentiation between RA and malignant pulmonary neoplasm.

Clear Cell "Sugar" Tumor of the Lung: A Well-Enhanced Mass with an Early Washout Pattern on Dynamic Contrast-Enhanced Computed Tomography

“…There are no specific lobar distributions (9). One of the characteristics on contrast-enhanced CT scan for the sugar tumor is the intense post-contrast enhancement (11) that appears to be related to its rich vascular stroma as described in rounded atelectasis in workers exposed to asbestos (12). In general, malignant nodules tend to be enhanced substantially more than benign nodules do (13-15).…”

Overview of the biochemical and genetic processes in malignant mesothelioma

“…However, despite the aforementioned methodological difficulties, ( 23 ) the information provided by that study is extremely useful for estimating the incidence of MM, as well as reinforcing the idea that the appropriate authorities should monitor the incidence of MM more closely in order to provide reliable data, as is done in the USA. ( 22 ) In addition to the abovementioned epidemiological study, ( 23 ) studies have been conducted in Brazil in an attempt to improve the diagnosis of MM ( 25 , 26 ) and find prognostic markers of MM. ( 27 )…”

Doenças asbesto-relacionadas

“…(3) Embora a lesão seja de natureza benigna, algumas vezes sua imagem radiológica é confundida com neoplasias malignas de pulmão, sendo que técnicas radiológicas especiais, além da tomografia computadorizada, têm sido propostas na tentativa de sua diferenciação. (11)(12)(13) A atelectasia redonda é geralmente assintomática.…”