[Rounded atelectasis: another pulmonary pseudotumor]. / Atelectasia redonda: otro seudotumor de pulmón.

Rounded atelectasis or Blesovsky's syndrome (also called pleuroma, folded lung or shrinking pleuritis with atelectasis) is the association of plaque-like pleural fibrosis with a folding visceral pleura and nodular atelectasis of the underlying lung. It can mimic a peripheral lung tumor or a mesothelioma. Radiography and computed tomography (CT) show a characteristic opacity with a comet-tail sign. The pathogenesis in some of the cases is considered to be secondary to pleural effusions and in others to a contraction of a focus of pleural fibrosis, not associated with effusion. In many cases, there was a history of asbestos exposure. We report the case of a 44-year-old, man who had smoked and worked with materials containing asbestos. He referred thoracic pain of 6 months duration and dyspnea. An X-ray of the chest (Fig. 1, 2) and a CT scan (Fig. 3) revealed a round peripheral mass in the left lower lobe. A fine needle aspiration biopsy of the lung was performed revealing clusters of large atypical cells with abundant cytoplasm. A thoracotomy was decided upon and no frozen section was requested. Gross examination of the resected lobe (Fig. 4) demonstrated a 2.5 cm white, irregular, firm and retracting pleural plaque. On sectioning, a peculiar folding of the visceral pleura delimited by anthracotic pigmentation was noted below the fibrotic plaque. The folding extended perpendicularly deep into the parenchyma. It was possible to separate the folding and liberate the underlying parenchyma, which was firm, fibrotic and atelectatic. No tumor was found anywhere within the lobe.(ABSTRACT TRUNCATED AT 250 WORDS)