Disorders of the thoracic cage and abdomen
Pain in the thorax or abdomen can be the result of a local problem of either the thoracic wall or the abdominal muscles but it is more often referred from a visceral structure or from another musculoskeletal source, most frequently a disc protrusion. Therefore, it is wise to remember the only safe approach in this area is to achieve a diagnosis by both positive confirmation of the lesion and exclusion of other possible disorders.
Referred pain
Pain referred from visceral structures
All visceral structures belonging to the thorax or abdomen may give rise to pain felt in this area (see Ch. 25). In that the discussion of these disorders is principally the province of internal medicine, only major elements in the history that are helpful in differential diagnosis from musculoskeletal disorders are mentioned here. Acute chest pain is summarized in Box 1.
Heart (Fig. 1)
Ischaemic heart disease
The innervation of the heart is derived from the C8–T4 segments. Pain is therefore not only felt in the chest but can also be referred to the ulnar side of both upper limbs, though more commonly to the left.
It is traditionally accepted that pain felt in the chest radiating into the left arm is indicative of myocardial ischaemia, especially when the patient reports it as pressure, constriction, squeezing or tightness. However, none of these descriptions, which are usually regarded as characteristic of ischaemia, is of definitive aid in the differential diagnosis from other non-cardiogenic problems in the thorax. Even relief of pain after the intake of glyceryl trinitrate does not offer absolute confirmation of coronary ischaemia. For clinical diagnosis, a combination of several elements must be present, of which the most important is pain spreading to both arms and shoulders initiated by walking, especially after heavy meals or on cold days.1
Mitral valve prolapse
This condition usually gives rise to mild pain located in the left submammary region of the chest and sometimes also substernally. Occasionally it mimics typical angina pectoris and is sometimes accompanied by palpitations.
Pericarditis
Pain that arises from the pericardium is the consequence of irritation of the parietal surface, mainly from infectious pericarditis, seldom from a myocardial infarction or in association with uraemia. When pericarditis is the outcome of one of the latter two causes it is usually only slight. Pain is normally located at the tip of the left shoulder, in the anterior chest or in the epigastrium and the corresponding region of the back. Three different types of pain can be present. First and most obvious, but rarely encountered, is pain synchronous with the heartbeat. Second is a steady, crushing substernal ache, indistinguishable from ischaemic heart disease. Third and most common is pain caused by an associated localized pleurisy, which is sharp, usually radiates to the interscapular area, is aggravated by coughing, breathing, swallowing and recumbency, and is alleviated by leaning forward.2
Aorta
Aneurysm of the thoracic aorta
This is most frequently the result of arteriosclerosis but is rare by comparison with the same condition below the diaphragm. The majority of small aneurysms remain asymptomatic, but if they expand a boring pain results, usually from displacement of other visceral structures or erosion of adjacent bone. Compression of the recurrent nerve may result in hoarseness and compression of the oesophagus in dysphagia. When acute pain and dyspnoea supervene, this usually indicates that the aneurysm has ruptured, with a likely fatal outcome.
Dissecting aneurysm of the thoracic aorta
This is an exceptional cause of chest pain, occurring mainly in hypertensive patients. The process usually starts suddenly in the ascending aorta, giving rise to severe substernal or upper abdominal pain. Radiation to the back is common and back pain may sometimes be the only feature, expanding along the area of dissection as it progresses distally. The patient often describes the pain as tearing. In most cases, it is not changed by posture or breathing.
When aortic dissection involves the vessels that supply the spinal cord, neurological changes and even paraplegia may result.3
Pleuritic pain
Pleuritic chest pain is a common symptom and has many causes, which range from life-threatening to benign, self-limited conditions. Because neither the lungs nor the visceral pleura have sensory innervation, pain is only present if the parietal pleura is involved, which may occur in inflammation or in pleural tumour. Invasion of the chest wall by a pulmonary neoplasm also provokes pain.
Clinical presentation
Pleuritic pain is localized to the area that is inflamed or along predictable referred pain pathways. Parietal pleurae of the outer rib cage and lateral aspect of each hemidiaphragm are innervated by intercostal nerves. Pain is therefore referred to their respective dermatomes. The central part of each hemidiaphragm belongs to the C4 segment and therefore the pain is referred to the ipsilateral neck or shoulder.
The classic feature is that forceful breathing movement, such as taking a deep breath, coughing, or sneezing, exacerbates the pain. Patients often relate that the pain is sharp and is made worse with movement. Typically, they will assume a posture that limits motion of the thorax. Movements of the trunk which stretch the parietal pleura may increase the pain.
During auscultation the typical ‘friction rub’ is heard. The normally smooth surfaces of the parietal and visceral pleurae become rough with inflammation. As these surfaces rub against one another, a rough scratching sound, or friction rub, may be heard with inspiration and expiration. This friction rub is a classic feature of pleurisy.
Aetiologies
Pneumonia
Although the clinical presentation of pneumonia may vary, classically the patient is severely ill with high fever, pleuritic pain and a dry cough.4
Carcinoma of the lung
In carcinoma of lung, pain is consequent upon involvement of other structures such as the parietal pleura, the mediastinum or the chest wall. Invasion of the chest wall may cause spasm of the pectoralis major muscle, which subsequently leads to a limitation of both passive and active elevation of the arm.
Pleural tumour
Malignant mesothelioma is a diffuse tumour arising in the pleura, peritoneum, or other serosal surface. The most frequent site of origin is the pleura (>90%), followed by peritoneum (6–10%), and only rarely other locations. Mesothelioma is closely associated with asbestos exposure and has a long latency (range 18–70). There is no efficient treatment and the overall survival from malignant mesothelioma is poor (8.8 months).5,6
Pleuritis
This is characterized by a sharp superficial and well-localized pain in the chest, made worse by deep inspiration, coughing and sneezing. Viral infection is one of the most common causes of pleuritic pain.7 Viruses that have been linked as causative agents include influenza, parainfluenza, coxsackieviruses, respiratory syncytial virus, mumps, cytomegalovirus, adenovirus, and Epstein-Barr virus.8
Pulmonary embolism
Pulmonary embolism is the most common potentially life-threatening cause, found in 5–20% of patients who present to the emergency department with pleuritic pain.9,10
Predisposing factors for pulmonary embolism are: phlebothrombosis in the legs, prior embolism or clot, cancer, immobilization, prolonged sitting (aeroplane), oestrogen use or recent surgery.11
Symptoms and signs are mainly dependent on the extent of the lesion. A small embolus may give rise to effort dyspnoea, abnormal tiredness, syncope and occasionally to cardiac arrhythmias. A medium-sized embolus may lead to pulmonary infarction, so provoking dyspnoea and pleuritic pain. In a massive pulmonary embolus, the patient complains of severe central chest pain and suddenly shows features of shock with pallor and sweating, marked tachynoea and tachycardia. Syncope with a dramatically reduced cardiac output may follow. This is a medical emergency: death may follow rapidly.
Acute pneumothorax
This is characterized by a sudden dyspnoea and unilateral pain in the chest, radiating to the shoulder and arm on the affected side and often described as a tearing sensation. Breathing and activity increase the pain. The typical features of pneumothorax are tachycardia, hyperresonance on percussion and decreased breath sounds on auscultation.
Superior sulcus tumour of the lung (Pancoast’s tumour)
This warrants special attention because 90% of patients suffering from this disorder complain of musculoskeletal pain.12,13 It is frequently mistaken for a shoulder lesion or even for thoracic outlet syndrome, an error which leads to a delay in diagnosis and treatment.14
The superior pulmonary sulcus is the groove in the lung formed by the subclavian artery as it crosses the apex of the lung. Because most apical tumours have some relation to the sulcus, they are often called superior sulcus tumours. They frequently involve the brachial plexus and the sympathetic ganglia at the base of the neck and may destroy ribs and vertebrae.
Pain around the shoulder, radiating down the arm and towards the upper and lateral aspect of the chest is usual and is often worse at night.
Orthopaedic clinical examination produces an unusual pattern of clinical findings. There is often a complicated mixture of cervical, shoulder and thoracic signs. Passive and resisted movements of the cervical spine may be limited and/or painful, the result of involvement of the scaleni and sternocleidomastoid muscles. On examination of the shoulder girdle, a restriction of both active and passive elevation of the scapula may be present. More positive signs are detected during examination of the shoulder.15 Both active and passive elevations of the arm are limited because of spasm of the pectoralis major muscle. Passive shoulder movements may be considerably limited in a non-capsular way. Some resisted movements are weak.
The neurological examination of the upper limb shows weakness and atrophy of the muscles on which consequent is extension of the tumour to the lower trunks of the brachialis plexus (Fig. 2). The only abnormal finding during thoracic examination is pain and limitation on lateral flexion towards the unaffected side explained by putting the affected thoracic wall under stretch.
Fig 2 The clinical symptoms of a superior sulcus tumour of the lung are produced by local extension into the chest wall, the base of the neck and the neurovascular structures at the thoracic inlet.
The clinical picture of Pancoast’s tumour may be completed by some typical findings that are caused by an ingrowth of neurological and vascular structures at the apex of the lung.16
• Horner’s syndrome: this is characterized by an ipsilateral slight ptosis of the upper lid, miosis of the pupil and enophthalmos, together with decreased sweating on the same side of the face. It is the outcome of involvement of the ascending sympathetic pathway at the stellate ganglion on the side of the tumour.17
• Hoarseness: this is the result of involvement of the recurrent laryngeal nerve, which innervates the voice cords. The hoarseness is unusual and unlike that caused by local laryngeal problems.
• Oedema and discoloration of the arm: this occurs if the subclavian vein is obliterated by the tumour.
All the symptoms and signs mentioned (summarized in Box 2), either singly or in combination, call for careful clinical chest examination followed by further investigation by chest radiography or other imaging methods.
Mediastinal problems
Acute mediastinitis
This is a rare inflammation, usually the result of perforation of the oesophagus. The three causes are perforation of malignant tumour, ingestion of caustics leading to necrosis and Mallory–Weiss syndrome, in which vomiting without appropriate relaxation of the oesophagus causes a tear of the oesophagogastric junction, often incomplete in thickness. There is very severe substernal and central dorsal pain of abrupt onset, followed by high fever and shock. Without treatment, it is rapidly fatal.
Mediastinal emphysema
This is usually the consequence of a ruptured pleural bleb or a wound of the chest. Air spreads into the mediastinal tissues, giving rise to sudden or more gradual substernal pain, sometimes radiating into the neck, shoulders and interscapular area. Subcutaneous crepitus above the clavicle is pathognomonic for the condition.
Oesophagus (Fig. 3)
Oesophageal spasm
This occurs suddenly and gives rise to substernal aching not necessarily related to the intake of food. Relief is often obtained by drinking hot water.
Reflux oesophagitis
This is frequently due to a hernia of the stomach through the diaphragmatic hiatus. Pain is felt around the xiphoid process, can be very severe and may radiate to the rest of the sternum, into the back and between the scapulae.18 Pyrosis or heartburn, which begins if the patient lies down immediately after meals, together with a burning sensation on eructation, are the most typical symptoms.
Malignant tumour of the oesophagus
The initial symptoms are food lodgement at the site of the tumour. Later there may be constant anterior or posterior central chest pain, unrelated to eating and mainly the result of extraoesophageal extension of the tumour. Total dysphagia may follow, and remarkable weight loss over a short period of time is an ominous sign.
Diaphragm (Fig. 4)
Diaphragmatic irritation
This can be the result of a subphrenic abscess or of air in the abdomen after laparoscopy or laparotomy. Pain arising from the central part of the diaphragm is referred to the base of the neck and into the shoulders, mainly in the third and fourth cervical segments. Pain originating from the peripheral part is felt more at the lower thorax and in the upper abdomen.
Diaphragmatic hernia
This usually occurs due to displacement of the proximal part of the stomach as a whole when the patient is prone or head down or when intra-abdominal pressure is increased, as on straining or lifting. Pain, pyrosis and dysphagia may result. Pain usually disappears in the upright position. Hernia often causes reflux oesphagitis (see above).
Subphrenic abscess
Abscesses that are truly just below the diaphragm can occur either to the right or to the left. Many so-called subphrenic abscesses are in fact below the liver and usually follow a perforation of the gastrointestinal or biliary tract, often after surgery. Signs and symptoms are fever and upper quadrant pain, sometimes with associated shoulder pain and local tenderness along the costal margin. Dyspnoea may be associated. Persistent fever and a history of a recent intra-abdominal sepsis should arouse suspicion.
Stomach and duodenum (Fig. 5)
Gastritis
An inflammation of the superficial gastric mucosa may be the result of the intake of non-steroidal anti-inflammatory drugs, alcohol or excessive meals. There is usually epigastric pain of short duration.
Gastric or duodenal ulcer
These result in epigastric or substernal pain, often associated with inability to digest food. The pain usually ceases on intake of antacids or food. Other symptoms, such as nausea, vomiting, heartburn and flatulence, are atypical. In duodenal ulcer, the pain commonly comes on through the night and also occurs 1–
hours after meals. A bout of symptoms over weeks or months may be followed by a similar period of relief. Pain in the back suggests a posterior ulcer that has penetrated a structure such as the pancreas.
Liver, gallbladder and bile ducts (Fig. 6)
Acute hepatitis
In acute hepatitis, enlargement of the liver, with subsequent stretching of the capsule, can give rise to pain felt in the right hypochondrium and upper abdomen. The development of jaundice is indicative of hepatitis and the liver is tender on palpation. It should be remembered that hepatitis B infections may be preceded in one in four cases by a polyarthritis affecting the smaller joints.
