Chapter 1 Integument problems
1.1 Introduction
Many lesions of skin or subcutaneous tissue are easily recognised and a diagnosis can be made virtually on inspection alone. Lipomas, ‘sebaceous’ cysts and ganglia are very common and usually have classic diagnostic features. Subcutaneous swellings are thus commonly benign — malignancies are rare but important to recognise. Many focal surface lesions are also benign and easily diagnosed; however, skin cancers are also common and any hint of malignancy requires biopsy for a certain diagnosis.
Focal skin lesions are divided morphologically into four main types: macules; papules or nodules; vesicles or pustules and wheals (Fig 1.1).
A macule is a localised surface change in skin colour without bulk or substance. It is important to note whether the colour change is permanent or blanches on compression. A lightly pigmented brown or tan macule is called a lentigo or freckle. A papule is a small solid projection above the skin surface; a larger papule is called a nodule. A flattened nodule is described as a plaque. Vesicles are elevated fluid-containing lesions: When large they are called bullae or blisters and when they contain pus, pustules. Acne (Greek — a facial eruption) comprises multiple small pustules, which if embedded are described as comedoform. Milia are tiny embedded cutaneous plaques due to keratinous retention foci; they are most common on the facial skin. Wheals are white, raised lesions of localised dermal oedema without blistering. Widespread wheals are often called urticaria, an atopic (allergic) reaction. If the skin is broken the lesion is an ulcer. Distinct morphological types of ulcer are also described (Fig 1.2).
Figure 1.2 Types of epithelial ulceration
Sources: Squamous cell carcinoma: From Rakel 2007; Basal cell carcinoma: From Rakel 2007; Venous ulcer: From Bolognia et al 2007; Neuropathic ulcer: From Bolognia et al 2007; Peptic ulcer: Courtesy of Robin Foss, University of Florida; Anal fissure: Courtesy of Gershon Effron, Sinai Hospital of Baltimore; Keratoacanthoma: From Habif 2003.
The clinical history of a lump or ulcer
1 Onset and duration
It is important always to ask the patient’s opinion of the cause of the lesion or of any incident associated with its onset. The patient may relate the lesion to an occupation, a drug or an injury. The length of history gives some idea of prognostic significance. The onset of skin lesions may be related by the patient to a triggering factor such as an insect bite. A previous history of repeated trauma may be important in pyogenic granuloma and in implantation dermoid cyst. A sudden change in the characteristics of a pre-existing mole suggests melanoma. Other skin lesions may be induced by local or systemic drug treatment.
2 Change and progression
The rate of progression helps to distinguish between benign and malignant conditions (Table 1.1). A skin lesion that progresses to a significant lump within a few days suggests infection (e.g. pyogenic granuloma); in a few weeks, hyperplasia (e.g. keratoacanthoma); or over several months, malignancy (e.g. basal and squamous cell carcinoma, melanoma). A pigmented skin lump that has not changed over several years suggests a benign mole. Most subcutaneous lumps are benign and very slowly progressive. ‘Sebaceous’ or epidermoid cysts are prone to infection, partial resolution and recurrence. Sometimes a ganglion may rupture after trauma and disappear, to return later. Abdominal wall hernias may appear suddenly after a strain and slowly progress; they are usually reducible and reappear on standing. Basal cell carcinomas may appear to heal in part of their circumference but are usually inexorably progressive.
Length of history | Clinical appearance | |
---|---|---|
Basal cell carcinoma | Months to years | Pearly nodule |
Central crusting and ulceration | ||
Rolled or beaded, telangiectatic edge | ||
Any site, especially head and neck | ||
Squamous cell carcinoma | Months | Indurated, ulcerating, raised nodule, everted friable edge |
Contact bleeding | ||
Sun-exposed surfaces | ||
Keratoacanthoma | Weeks | Rapidly growing |
Dome shaped | ||
Volcanic apical ulceration | ||
Sun-exposed surfaces | ||
Pyogenic granuloma | Days or weeks | Small, soft, cherry red lesions |
Contact bleeding | ||
Common on mucocutaneous surfaces |
4 Multiplicity
The history should be completed by a general systems review and the family, social, occupational and allergic history. This is particularly important for skin ulcers where systemic diseases such as alcoholism, rheumatoid arthritis and diabetes are important factors to consider, both in aetiology and in treatment. Diabetes mellitus is frequently a factor in delayed healing of ulcers. Some conditions have a particular geographical predisposition such as the ‘Bairnsdale ulcer’ for which the aetiology is an atypical mycobacterium of limited geographical range.
The physical examination of a lump or ulcer
An abnormality in a bilateral structure should be compared and contrasted with its normal side. Assessment of a lump traditionally follows a sequential analysis of its characteristics (Box 1.1). Although not all the features are applicable to all lumps, it is essential to follow an ordered sequence when characterising any lump. The most important features are the site (which should be defined anatomically in all dimensions) and the physical characteristics, including relationships of the lump to its surroundings.
3 Shape and surroundings
A smoothly regular spherical lump strongly suggests a cyst. Most solid lumps have slight or prominent irregularities of shape, even when generally spherical or oval. To describe a lump’s shape as spherical implies that it has been assessed totally in three dimensions. This is only possible with very mobile lumps or when an adjunct to examination such as an ultrasound is available. More often only a portion of the circumference of the lump can be felt and its roundness implied from this assessment. Cystic liquid collections are common in skin and subcutaneous tissues and include ‘sebaceous’ cysts and bursae.
Ulcers can be regular or irregular in shape and their edges can also be described as serpiginous, sloping, everted, rolled, overhanging or punched-out (Fig 1.2). Brown pigmentation, a desquamative rash and induration of skin and subcutaneous tissues around an ulcer suggest venous insufficiency. Redness, heat, oedema and cellulitis indicate active spreading infection.
5 Contour
6 Consistency
Apart from these four grades, familiar analogies can help to describe size and consistency (e.g. golf ball or tennis ball size and feel). A diagnostic description (solid or cystic lump) combines the clinical features of shape, contour, consistency and other aspects.
9 Transillumination
Bursae, hydroceles and epididymal cysts are common transilluminable lumps. Ganglia involving tendon sheaths usually transilluminate. Firmer, deeper ganglia near joints usually do not. ‘Sebaceous’ cysts do not transilluminate because of their pultaceous contents and thick walls. Lipomas are not usually transilluminable and never brilliantly so. Transillumination of a focal lump must be differentiated from the normal luminescence of subcutaneous tissue around the beam of a torch.
10 Fluctuation and percussion
Fluctuation is tested (preferably in two planes at right angles to each other) with a compressing and a testing finger. The lump must be fixed to ensure that it has not been itself moved by the compressing finger. The transmitted impulse of fluid is appreciated by the second, testing finger (Fig 1.3). A variation of this test is the demonstration of a fluid thrill in ascites. With some lumps, three fingers can be used conveniently. Two fingers of one hand on opposite sides of the lump control it and both test for transmission of an impulse when the index finger of the other hand compresses the lump, or both compress the lump while the index finger of the other hand tests for fluctuation.
11 Fixity
Mobility on swallowing is an important sign for neck swellings: structures normally related to the trachea or larynx exhibit this sign, which is characteristic of a goitre (Ch 2.15). Movement on inspiration occurs when intraperitoneal lumps are related to the under surface of the diaphragm (liver, spleen).
1.2 Focal skin lesions
Most focal skin lesions will be manifestly benign longstanding lesions of congenital or acquired origin that have caused the patient no problem and require no treatment. Benign skin lesions include a large number of congenital blemishes, moles, malformations and hamartomas. Benign neoplasms, localised infections and miscellaneous causes are also common (Fig 1.4). An important group of lesions are dysplastic and premalignant. Accurate diagnosis of this latter group is extremely important, as early surgical treatment of suspicious skin lesions is curative for most forms of skin malignancy. Screening programs and self-examination in high-risk populations have been employed but vary in effectively diagnosing early lesions. Repeated practice at assessing common skin lesions rapidly improves diagnostic skills. Accurate diagnosis relies first on a careful history and examination.
Focal skin disorders can be assessed on clinical grounds into:
Pigmented lesions (naevi) form a distinct category within each of these two groups.
Clearly benign lesions
Benign skin lesions will usually have been present from birth or for many years without change. In children and adolescents, congenital moles and vascular malformations are common, as are freckles and infective warts; skin malignancies are rarely seen (Box 1.2). In adulthood, degenerative and other specific lesions occur with increasing frequency in patients over the age of 40 years (Box 1.3); differentiation of benign lesions from cancers becomes increasingly important. Lesions are defined as macules or nodules. Common macules are the port wine stain, café au lait spots (neurofibromatosis), some junctional naevi and freckles. Freckles are common in children and adolescents. In older patients senile freckling of the skin is common, as are spider naevi and senile purpura. Common benign nodules include pigmented moles and angiomas. Verrucous lesions are also common in children and adults. Benign skin tags and keratoses are seen with increasing frequency in older patients. Benign traumatised lesions may ulcerate. In adults this always invokes suspicion of malignancy; in children benign ulcerated or infective lesions are relatively common. Skin vesicles occur with herpetic infections, eczema and impetigo.
Clinical features, diagnostic and treatment plans
Children
Intradermal, junctional and compound naevus
Intradermal naevus is the most common benign mole, deriving its name from the fact that the pigment cells lie entirely within the dermis (Fig 1.5). The macroscopic appearance varies considerably: from a soft flattened pale brown or flesh-coloured nodule or macule, to a deep brown warty excrescence. The edge is usually well defined. Many contain hair, which is a helpful diagnostic point — hairy moles are virtually always intradermal and benign. Intradermal naevi occur all over the body skin and are usually present from birth but are rare on the palms or finger-tips. They vary in size from a few millimetres to large lesions several centimetres across. They are biologically conservative, wholly benign lesions, throughout life.