Книги по МРТ КТ на английском языке / Thomas R., Connelly J., Burke C. - 100 cases in radiology - 2012

CASE 21: YOUNG MAN WITH NECK SWELLING

History

This 17-year-old man presents to his GP with a swelling at the base of his neck that he noticed recently after swimming. He also complains of tiredness, some loss of appetite and night sweats developing over the last 4–6 weeks. There is no other medical history. He has not travelled outside Europe and is not aware of recent exposure to any infectious disease.

Examination

On examination he has normal weight and does not appear unwell. He has normal observations. There is a palpable mass in the left supraclavicular fossa and prominent nodes in the neck and axillae. The chest is clear. The abdomen is soft and not tender. You take blood tests and arrange for a chest radiograph (Figure 21.1).

Figure 21.1 Chest radiograph.

Questions

•What abnormalities are seen on the chest radiograph?

•What differential diagnosis would you consider?

•What other investigations would you consider for diagnosis?

63

ANSWER 21

The chest radiograph shows marked enlargement of the hila and mediastinum with multiple rounded masses. Multiple soft tissue masses are also noted in both lungs. The heart and bones appear normal.

The differential diagnosis to be considered is that of bilateral hilar and mediastinal enlargement with multiple lung masses. The hilar masses are lymph nodes and massively enlarged. The mediastinal masses are likely to be in the anterior or middle mediastinum as the thoracic spine and aortic outlines are clearly seen. At 17, the patient is young enough to consider congenital causes but the recent symptoms and the widespread appearance are suggestive of an acquired disorder. The differential could include neoplastic causes such as lymphoma, leukaemia, germ cell tumour, metastases from sarcoma or possibly a Wilms’ tumour, inflammatory lymphadenopathy from tuberculosis, sarcoidosis, histoplasmosis or, less likely, a congenital cause such as lymphatic malformation. The most likely diagnosis is Hodgkin’s lymphoma.

Cross-sectional computed tomography (CT) imaging is required (Figure 21.2), also below the diaphragm to assess and stage the extent of disease. A tissue sample is also required and this can be obtained by percutaneous biopsy of an enlarged superficial lymph node (e.g. in the neck) or by endobronchial ultrasound-guided aspiration from a hilar lymph node. Washings can also be taken to rule out tuberculosis.

Figure 21.2 Coronal computed tomography (CT) slices through (a) the thorax with arrows showing mediastinal, hilar and pulmonary lymphadenopathy; (b) the abdomen showing enlarged pancreatosplenic lymph nodes and a low attenuation lesion in the spleen.

Some nodes have lower attenuation centrally, suggesting necrosis. These finding are significant for the staging and treatment planning. Hodgkin’s lymphoma responds well to chemoand radiotherapy with good long-term survival, and the long-term side effects of treatment must be considered when planning treatment regimes.

64

The radiology department may be involved in placing an indwelling catheter for regular chemotherapy. Imaging is also required to assess response, typically CT. Subsequently, imaging is used to assess for recurrence and complications.

KEY POINTS

•On a chest X-ray, mediastinal lymphadenopathy may increase the angle of the carina or give the upper mediastinum a bumpy outline. Increased hilar bulk that does not appear to be vascular may be lymphadenopathy.

•Massive lymphadenopathy is suspicious for lymphoma.

65

CASE 22: COLLAPSE AND POSSIBLE SEIZURE

History

A 75-year-old woman is brought into the accident and emergency department following a collapse at home. She has no recollection of the event and appears very confused. Her husband found her on the floor and is worried that she may have hit her head on some furniture. The husband gives a history of his wife being ‘under the weather’ and ‘not quite herself’ for several months, although he is unable to explain more specifically. She has otherwise been fit and well and takes medication for blood pressure and for osteoporosis prophylaxis.

Examination

On examination, routine observations are normal. Her Glasgow Coma Score (GCS) is 15 and Mini Mental Test score 6/10. She has mild left-sided limb weakness that appears to be resolving. The chest, cardiovascular and abdominal examination is normal.

You arrange tests including an urgent computed tomography (CT) scan of the head (Figure 22.1), as called for by the National Institute for Health and Clinical Excellence (NICE) guidelines on head injury criteria, including the patient’s age and amnesia.

Figure 22.1 Axial non-contrast CT scan through the brain at the level of the quadrigeminal cistern.

Questions

•What does the CT show?

•What would you do next?

67

ANSWER 22

The CT shows a large lobulated mass with homogeneously increased attenuation in the right parasagittal frontal lobe. There is mass effect with effacement of the frontal horn of the right lateral ventricle and 1 cm shift of the midline to the left. There is minimal surrounding vasogenic oedema. There is no intracranial haemorrhage or infarct. The basal cisterns are patent.

When considering an intracranial mass, the first step is to decide if the mass arises within the brain (intra-axial), ventricles or cisterns, or from the adjacent structures (extra-axial) such as the meninges or the bone. More imaging using contrast-enhanced magnetic resonance (MR) (or contrast CT if this is not possible) is also done, as this is more sensitive to possible other lesions as well as giving more information about the tumour structure and the surrounding brain (Figure 22.2).

Figure 22.2 Gadolinium contrast-enhanced T1-weighted images of the brain showing a uniformly enhancing lobulated mass in the right frontal lobe.

The MR shows that the tumour grows from a broad segment of the meninges and appears to be growing along the falx at its edge (see arrow, Figure 22.2b), a so-called dural tail, that is quite characteristic for a meningioma or metastasis (particularly breast). The absence of other lesions and no history of a tumour elsewhere makes a metastasis less likely although it is important to look. Meningiomas frequently have associated calcification and adjacent bone change. The differential also includes intra-axial tumours and lymphoma, although appearance and position make this less likely.

Meningiomas occur intracranially and within the spinal canal arising from the arachnoid layer. They are common, second only to glioblastoma in frequency. The parasagittal position is the most common (33–50 per cent), although other common sites are near the vertex or by the lesser wing of sphenoid or petrous ridge. Ninety per cent are benign but because they grow slowly they can eventually have a space-occupying effect, become

68

symptomatic and as a result tend to be discovered later in life. Surprisingly, the symptoms can seem disproportionately mild for such large tumours. This probably reflects the slow onset and adaptation but also the nature of the prefrontal lobe symptoms, which include change in mentation, apathy or disinhibited behaviour and urinary incontinence that are sometimes attributed to ageing.

KEY POINTS

•Meningiomas are common, usually benign, relatively silent intracranial tumours.

•The onset and associated symptoms are often insidious and mild until there is a significant mass effect.

Reference

1.National Institute for Health and Clinical Excellence (NICE) (2007) Head injury; triage, assessment, investigation and early management of head injury in infants, children and adults. www.nice.org.uk/nicemedia/live/11836/36257/36257/.pdf

69

CASE 23: PREMATURE NEONATE WITH ABDOMINAL DISTENSION

History

A 6-day-old premature baby born at 31 weeks’ gestation on the neonatal unit is noted to be lethargic and increasingly intolerant of feeds, with decrease in oxygen saturation and abdominal distension.

Examination

Serial abdominal radiographs are obtained (Figure 23.1 and 23.2).

Questions

•Multiple tubes and lines can be seen in Figure 23.1. What are the two tubes seen in the centre of the radiograph?

•What radiological signs are seen in Figure 23.2?

•What is your differential and most likely diagnosis?

71