IntroductionThis chapter will discuss lung disorders that present throughout the childhood years, including infancy and the perinatal period. Some structural abnormalities are now detected earlier ...with recent advances in prenatal ultrasound. Areas considered include congenital malformations and disease processes associated with the transition from an intrauterine to an extrauterine existence, particularly when this occurs preterm. Cystic fibrosis (CF) and other inheritable conditions that typically present first in the pediatric age range will also will be covered. The pediatric aspects of conditions such as infection and tumors are also included but entities typically encountered in adults that rarely affect children will only be cross-referenced.Congenital malformationsCongenital malformations are morphological defects in part of an organ, a complete organ or a larger region of the body, due to an intrinsically abnormal developmental process. A morphological defect of the same structures due to the extrinsic breakdown of, or interference with, an originally normal developmental process is termed a disruption. These may be difficult to distinguish, especially if the disruption has occurred early in gestation. Some malformations are presumed multifactorial, due to interactions between genetic factors and environmental agents; others are purely environmental. It may be difficult to be sure where, in this etiological spectrum, some malformations should be placed. To understand defects in lung development it is essential to remember the embryology outlined in Chapter 1.
Pulmonary parasitic infections Lucas, Sebastian; Hasleton, Philip; Nelson, Ann-Marie ...
Spencer's Pathology of the Lung,
01/2013
Book Chapter
IntroductionMankind is afflicted with hundreds of parasitic diseases that affect every organ, including the upper and lower respiratory tracts. For some infections, man is the definitive host, i.e., ...the sexual or reproductive part of the parasite's life cycle takes place within the human body. For others, man is accidentally infected, i.e., humans interrupt another animal's parasitic life cycle. This latter scenario represents a dead end for the parasite, since reproduction is not possible.The main groups of parasites are protozoa (single cell organisms) and helminths (worms). The taxonomic classifications and interrelations of these can be complex and are of little interest to most pathologists. Occasionally pentastome parasites, worm-like animals that inhabit the upper respiratory tract of reptiles, birds and mammals, also obstruct the upper airways. These are mentioned only briefly in this account, which focuses on the commoner lower respiratory tract protozoal and worm infections.
Large cell carcinomaLarge cell carcinoma (LCC) is a “waste basket” histological group of non-small cell lung carcinomas (NSCLC). Prior to the 1999 World Health Organization (WHO) classification, ...these carcinomas were variously termed large cell anaplastic carcinoma or large cell undifferentiated carcinoma. In the current WHO classification, LCC is clearly defined as a malignant epithelial tumor composed of large cells lacking light microscopic or histochemical evidence of squamous, glandular or small cell differentiation. Nevertheless, this subgroup includes three distinctive histological entities, namely large cell neuroendocrine carcinoma (LCNEC), basaloid carcinoma and lymphoepithelioma-like carcinoma (LELC). In addition, two other morphological variants, namely clear cell and rhabdoid, warrant discussion (Table 1).Large cell carcinomas are poorly differentiated tumors diagnosed in the absence of glandular or squamous features. This small group represents no more than 10% of lung cancers. However, if classified on the basis of either electron microscopy or molecular findings, this category would account for a far smaller percentage of lung carcinomas. LCNEC and basaloid carcinoma may be the most common LCC, with each accounting for 3 to 5% of lung carcinomas. Lymphoepithelioma-like carcinoma accounts for 1% of lung tumors in China, but even fewer in Western countries.
Eosinophilic lung disease Tazelaar, Henry D.; L. Wright, Joanne; Ryu, Jay H.
Spencer's Pathology of the Lung,
01/2013
Book Chapter
IntroductionThere are numerous diseases associated with pulmonary eosinophilia. They represent a heterogeneous group of diseases that, except for the presence of eosinophils, sometimes bear little ...clinical relationship to one another. The most common disease associated with eosinophilia is asthma, and the pathologist's role in the diagnosis is non-existent, except when there are complications. The most common diffuse disease associated with eosinophilia is chronic eosinophilic pneumonia, which may or may not be associated with asthma. These and other less common diseases are discussed in this chapter. Pulmonary Langerhans' cell histiocytosis (formerly known as eosinophilic granuloma) and hypersensitivity pneumonitis (extrinsic allergic alveolitis, which is rarely associated with tissue eosinophilia) are discussed in Chapters 34 and 12, respectively.IntroductionAsthma is one of the commonest respiratory disorders and is characterized by airway hyperresponsiveness and inflammation. Over the past few decades, the prevalence of asthma has increased and affects as many as 300 million persons worldwide.
Diseases of the pleura Hasleton, Philip; Galateau-Salle, Francoise; King, Juliet ...
Spencer's Pathology of the Lung,
01/2013
Book Chapter
IntroductionThe pleura is host to many diseases, some systemic, others spreading from the underlying lung. Lung carcinoma metastases are the commonest lesions seen by pathologists. The most frequent ...cause of pleural problems is an effusion, secondary to congestive cardiac failure. This chapter will consider normal pleural physiology, as well as benign and malignant processes.The pleural space, separating the lung and chest wall, contains a small amount of liquid that lubricates the pleural surfaces during breathing (see Chapter 1). The volume of fluid in the pleural space is small, in the range of 0.2–0.5 ml. Normally, the protein and cellular content is low, with no inflammatory cells. The thin layer of liquid between the pleural surfaces has the important function of providing mechanical coupling between the chest wall and lung. For this connection to be effective, the volume of pleural liquid required for lubrication must be kept to a minimum. In addition, the colloid osmotic pressure must be low to keep this volume small. This fluid ensures instantaneous transmission of perpendicular forces between the two structures, and allows their sliding movement in response to shearing forces.
Pulmonary bacterial infections Woodhead, Mark; Klassen-Fischer, Mary; Neafie, Ronald C. ...
Spencer's Pathology of the Lung,
01/2013
Book Chapter
Background“Pneumonia”, wrote Laennec, “is one of the diseases most anciently known; and before pathological anatomy . . . had investigated the true nature of diseases, it was generally regarded as ...one of the internal afflictions most readily recognized.”Pneumonia occurs when the host mounts an inflammatory response, centered on the lung parenchyma, usually against a microorganism, but sometimes against another toxic agent, which has reached this normally sterile site. Bacteria are the most common causative microorganisms. The effect on the host is variable, ranging from complete absence of clinical manifestations to sudden death or a brief illness followed by sudden death. More typically the effects of the inflammatory response and the replacement of the normal gas-exchanging lung tissue cause a constellation of symptoms and signs. These are associated with, and may be diagnosed as, lung infection. Untreated, the condition progresses until the host dies or the inflammatory response overcomes the microbial threat and lysis of the toxic state is followed by gradual recovery. Recognition of the condition will usually lead to appropriate medical intervention, resulting in improved outcome in most cases.
