The pathology of honeycomb lung.

A form of cystic lung, characterized by numerous, widespread and usually small cavities, is a wellrecognized though apparently uncommon condition, which, according to earlier accounts, occurred especially in children (Sharkey, 1894; Tooth, 1897; Fletcher, 1901; Bernstein, 1905). Such lungs were described by Fowler and Godlee (1898) as having a worm-eaten or honeycomb appearance. Sharkey and Fletcher both believed that the cystic change developed acutely and the condition was generally interpreted as bronchiectasis, bronchiolectasis, or broken-down bronchopneumonic abscesses, thereby implying an acquired origin. To this diffuse form of cystic disease Oswald and Parkinson (1949) also applied the term honeycomb lung and they attempted to establish the nature of the disease process from observations on 16 instances including both children and adults. Having reviewed the literature, these authors concluded that honeycomb lung was probably an acquired inflammatory condition of diverse and often uncertain aetiology, but they were unable to exclude a developmental origin in some instances. Nine of Oswald and Parkinson's cases came to necropsy, and lungs from five, together with the case previously reported by Eernstein (1905), were selected by Cunningham and Parkinson (1950) for pathological investigation. These six cases were chosen because they appeared to have distinct histological features suggesting that they represented stages of the same granulomatous process ending in extensive pulmonary fibrosis and cyst formation. Three other examples of honeycomb lung examined by Cunningham and Parkinson were excluded from their report, since the histological characteristics, though not specified, were different, again suggesting multiple causation for honeycomb lung. Descriptions of honeycomb lung under other terms may, in the past, have obscured its frequency. For instance, Sandoz (1907) described foetal bronchiectasis in twin sisters, aged 18, in whom the anatomical and histological features were identical with those of honeycomb lung as given, below, while von Stossel (1937) and Rubenstein, Gutstein, and Lepow (1955) each reported two cases of this condition in adults as muscular cirrhosis of the lungs. Furthermore, it seems likely that the cases described by Mallory (1948) as granulomatous pneumonitis were also examples of honeycomb lurg. I have had the opportunity to study many cases of honeycomb lung, but, in addition to the diffuse form, have repeatedly encountered cases in which the disease affected only parts of the lung. Furthermore, the fibrocystic change was occasionally restricted to small circumscribed areas in the secondary lobules of the lung. The disease process, however, appeared to be the same irrespective of the extent and distribution of the changes. To elucidate further the pathogenesis of honeycomb lung its pathological anatomy was investigated by means of serial sections and the histology examined in detail.