Introduction The skin is commonly affected by a wide range of pathologies. Some of these are cutaneous manifestations of systemic disease processes whilst others are primary disorders of the skin. Common systemic viral illnesses such as measles and chickenpox are associated with characteristic skin rashes and many autoimmune and vasculitic disorders, such as systemic lupus erythematosus, dermatomyositis, scleroderma and Henoch–Schönlein purpura, present with skin manifestations. Primary…

Pituitary gland disorders Structural defects of the pituitary gland are few, although functional abnormalities are potentially numerous, leading to under- or overproduction of one or more of the many hormones produced by the pituitary gland and its target endocrine glands. The most important histopathological lesions of the pituitary gland are benign adenomas derived from the anterior pituitary (adenohypophysis). These commonly secrete anterior pituitary hormones and result…

Introduction The male reproductive system includes the testes with their related duct systems, the prostate and the penis. These organs are responsible for the production, storage and periodic emission of the male gametes, spermatozoa, as well as the production of male sex hormones, principally testosterone. The organs of this system are prone to the full range of pathological conditions seen in other organ systems. However, clinically,…

Introduction The female breast ( E-Fig. 18.1 H ) is dependent for its normal activity on oestrogen and progestogens and thus exhibits considerable structural and functional variation throughout life. Apart from the overt changes occurring during puberty, pregnancy, lactation ( E-Fig. 18.2 H ) and menopause, subtler changes also occur within the normal menstrual cycle. As a corollary, hormonal disturbances probably underlie various benign breast disorders…

Introduction The female reproductive tract comprises the vulva, vagina, uterus, fallopian tubes and ovaries. As in other systems, a wide range of pathological conditions may occur in these organs. Malignant tumours and their precursor conditions are of major pathological importance. An interesting feature of the female genital tract is that there is a range of epithelial malignancies that can occur at almost any site in the…

Functions of the lymphoreticular system The lymphoreticular system is composed of various organs and tissues which facilitate the interaction of lymphocytes with cells of monocyte–macrophage lineage in the generation of immune responses. The main organs and tissues of the system are the thymus ( E-Fig. 16.1 ), spleen ( E-Fig. 16.2 ), lymph nodes, bone marrow and mucosa- associated lymphoid tissue (MALT), such as tonsils (…

Introduction The urinary tract comprises the kidneys, pelvicalyceal systems, ureters, bladder and urethra. The kidney is responsible for excretion of the waste products of metabolism, the waste products being excreted in the form of an aqueous solution called urine . Urine passes from the kidneys into the pelvicalyceal systems and thence via the ureters to the bladder, which acts as a reservoir. Urine is held in…

Disorders of the liver The liver is affected by a wide range of disorders, the most important of which are listed below. The liver performs many different metabolic functions and liver disease produces diverse clinical symptoms and signs. The pathophysiology of the more common symptoms and signs is described in Table 14.1 . ▪ Acute hepatic necrosis has been described in Ch. 2 . This usually…

Introduction The alimentary system includes the mouth and its associated salivary glands, the oesophagus, stomach, small and large bowels, appendix and anus. The function of the alimentary tract is the ingestion, digestion and absorption of nutrients, along with the storage and expulsion of waste products. A wide range of congenital and acquired diseases may affect all parts of the tract. Diseases of the oral tissues and…

Diseases of the nose and pharynx Allergic rhinitis (hay fever) commonly affects the nose, paranasal sinuses and nasopharynx and can predispose to inflammatory nasal polyps ( Fig. 12.1 ). The sinonasal (Schneiderian) papilloma is particular to the nasal cavity and is usually unilateral ( Fig. 12.2 ). Malignant tumours of the nasal passages and sinuses are rare, but nasopharyngeal carcinoma ( Fig. 12.3 ) is of…

The cardiovascular system includes the heart, blood vessels and circulating blood and is often referred to as the circulatory system. In this chapter, we will focus upon diseases affecting the blood vessels (the arteries and veins) and the heart. Diseases of the arterial system The most common pathological abnormality of the arterial tree is thickening and hardening of the walls, known as atherosclerosis (see Ch. 8…

Introduction When there is sustained occlusion of arterial blood supply or venous drainage, a type of necrosis can occur called infarction . Common clinical examples of infarction are myocardial infarction (affecting the heart) and cerebral infarction or stroke (affecting the brain). In these situations, the myocardial or cerebral vessels are affected by atherosclerosis, thrombosis or embolism. If the blood supply is temporarily altered, then this can…

Thrombosis The vascular system normally contains fluid blood. However, it is often necessary for blood to coagulate to prevent bleeding following injury to a vessel wall. To control this process of haemostasis , there are interacting systems that either promote or inhibit the process of blood coagulation. These systems are normally well regulated. Under certain pathological circumstances these dynamics may be disrupted, leading either to haemorrhage…

The wall of an artery has three layers, the intima, media and adventitia, which are separated from each other by thin elastic fibres known as the elastic laminae ( E-Fig. 8.1 ). The intima, the innermost layer, is composed of fibroelastic tissue and is lined by a thin layer of endothelial cells along its luminal aspect. The media contains bundles of smooth muscle and is separated…

Cellular atypia and dysplasia In the previous chapter, we considered cellular adaptations to a variety of stimuli resulting in alterations in their pattern of growth, whilst still achieving full differentiation Occasionally, cells have an increased rate of division such that they do not have time to reach complete maturation (with full development of cytoplasmic specialisation) before another cycle of cell division supervenes. This leads to a…

Introduction Cells exist in, and must adapt to, an environment that is continually changing, reflecting not only physiological processes but also external influences such as drugs or toxins. As briefly discussed in Ch. 2 , if the stimulus is overwhelming, the cells undergo degeneration or cell death. However, many less noxious stimuli cause cells to adapt by altering their pattern of growth. This may occur in…

Introduction A number of infections may be diagnosed from the characteristic appearances seen in biopsy specimens. In some cases, the diagnosis may first be suspected when a biopsy is examined by light microscopy. In other cases, the clinician suspects an infective agent and seeks confirmation by biopsy as well as by other means. Although histological appearances are often characteristic, it is usually necessary to confirm the…

Introduction In developed countries, where the major pyogenic infections have been brought more or less under control, chronic inflammatory conditions result in a huge burden of morbidity and mortality. In less industrialised countries, certain infections, such as tuberculosis, typically cause a chronic inflammatory response and are responsible for a large amount of disease. By definition chronic inflammation lasts longer than acute inflammation. Different stimuli may cause…

Introduction Inflammation is an almost universal response to tissue damage by a wide range of harmful stimuli, including mechanical trauma, tissue necrosis and infection. The purpose of inflammation is to destroy (or contain) the damaging agent, initiate repair processes and return the damaged tissue to useful function. Inflammation is somewhat arbitrarily divided into acute and chronic inflammation , but, in reality, the two often form a…

Introduction In response to environmental changes, cells have to adapt in the face of physiological and pathological stimuli that seek to disturb their normal homeostatic milieu. This process is called cellular adaptation and includes mechanisms such as an increase in cell size (hypertrophy) or an increase in cell number (hyperplasia) . Other examples of cellular adaptation include metaplasia , which can be defined as a change…