Lymphoma

Regarding lymphomas,

1. Mesenteric nodes are commonly involved in Hodgkin's lymphoma
2. Nodal extension is contiguous in HL
3. Extranodal disease is common in NHL
4. Testicular lymphoma is the most common testicular tumor in people aged over 60 years
5. Adrenals are common extranodal sites for lymphomatous involvement

Answers: F, T, T, T, F

Notes: Axial, peripheral and mesentric nodes are commonly involved in NHL and mesentric nodes are rarely involved in HL. Nodal extension may be non-contingious in NHL, usually contigious (more often single nodal group) in HL. Extranodal disease is rare in HL (4-5%), common in NHL (20-40%). Lymphomatous involvement of kidneys is usually bilateral and contiguous retroperitoneal extension is seen with renal lymphoma in 25% and should not be mistaken for RCC. Involvement of adrenal in is rare (only 4% of NHL). In up to 40%, testicular lymphoma is bilateral and multifocal and is most common testicular tumor in people over 60 years. Gastric lymphomas account for 3-5% of gastric malignancies and far less common than adenocarcinomas and GISTs.

References:
Liete NP et al. Cross-sectional Imaging of Extranodal Involvement in Abdominopelvic Lymphoproliferative Malignancies.RadioGraphics 2007;27:1613-1634

Tuberculosis

Regarding tuberculosis,

1. Radiographic evidence of hilar lymphadenopathy is more common in adults than in children
2. Cavitation is hallmark of post-primary TB
3. In TB meningitis, abnormal meningeal enhancement is more often seen in the basal cisterns
4. In spinal TB, calcification of abscess is characteristic
5. Calcification is seen more than 50% of renal TB

Answers: F, T, T, T, T

Notes: Radiographic evidence of lymphadenopathy is more common in children (96%) than in adults (46%) and more often seen in the right hilar and right paratracheal location. Cavitation is hallmark of post-primary TB, where as lymphadenopathy is rare (5%). Calcification of abscess is highly specific of TB spine. In renal TB, calcification is seen in more than 50% and the other findings include calcyceal deformity and papillary necrosis.

Reference: Burrill J et al. Tuberculosis: A Radiologic Review. RadioGraphics 2007;27:1255-1273

Fibrosing mediastinitis

Regarding fibrosing mediastinitis,

1. Commonly produces compression of the mediastinal structures
2. Associated pleural or pulmonary changes are common
3. Associated with histoplasmosis
4. Diffuse type is more common than focal type
5. Focal type commonly calcifies

Answers: T, T, T, F, T

Notes:
Fibrosing mediastinitis is a rare condition causing excessive fibrous tissue deposition. The etiology is often unknown. About 90% have compression of the medastinal structures, the most common being compression of the SVC and/or pulmonary artery. About 67% have pleural or pulmonary changes. Localised fibrosing mediatinitis has been associated with histoplasmosis.

2 patterns are recognised: focal and diffuse. Focal pattern is seen in 82% and is frequently calcified (63%). Diffuse form is diffusely infiltrating, noncalcified mass.

References:
1. Devraj A et al. Clinical Radiology. Volume 62, Pages 781-786
2. Rossi S E et al. Fibrosing mediastinitis. Radiographics. 2001;21:737-757.)

Marfan's syndrome

The following are true regarding Marfan's syndrome (MS):

1. It is autosomal dominant
2. The most common cause of death is secondary to cardiovascular complications
3. Pectus excavatum is commonly seen in Marfan's syndrome
4. Dural ectasia can be seen on the plain radiographs as widening of the interpedicular distance
5. Spontaneous pneumothorax is usually secondary to bullae

Answers: T, T, T, T, T

Notes:
MS is autosomal dominat disease with the gene located on chromosome 15. Aortic dissection, heart failure and vavular disease are the most common causes of death in more than 90%. The cardiovascular manifestations include annuloaortic ectasia, aortic aneurysm, aortic dissection, pulmonary arterial dilatation. Musculoskeletal menifestations include scoliosis, pectus excavatum, pectus carinatum, arachnodactyly, protrusio acetabuli. Dural ectasia may be seen as widened interpedicular distance. Pulmonary manifestations include interstitial lung disease, bullous emphysema, bronchial anomalies, bronchiectasis, spontaneous pneumothorax.

Reference:
Ha H I et al. Imaging of Marfan Syndrome: Multisystemic Manifestations. RadioGraphics 2007;27:989-1004

Venous Thromboembolism

Regarding venous thromboembolic disease,

1. Deep venous thrombosis and pulmonary emboli can be diagnosed using MRI.
2. D-dimer assays have a high positive predictive value in suspected venous thromboembolic disease.
3. Duplex ultrasound is highly sensitive and specific investigation for symptomatic proximal leg deep venous thrombosis.
4. The more distal the leg venous thrombosis, the more risk for pulmonary embolism.
5. The dose of VQ (ventilation perfusion) scan is more than that for a CTPA (CT pulmonary angiogram).

Answers: T, F, T, F, F

Notes: DVT (Deep Venous Thrombosis) and PE (Pulmonary Embolism) are one of the major common challenges in day-to-day radiology practice. There are no common censuses or guidelines in the diagnosis and management of DVT or PE. D-dimer has a high negative predictive value, i.e. excluding DVT or PE, but it lackes positive predictive value. Duplex ultrasound remains investigation of choice in most of the hospitals to exclude or confirm DVT as this investigation is highly sensitive and specific (both >90%). VQ scan still remains a very common investigation in the diagnosis of PE and is based on PIOPED trail. Although conventional angiography is traditionally considered as a gold standard, CTPA is gaining wider acceptance in diagnosing PE, despite more dose than VQ scan. MRI is being tried in the diagnosis of PE and DVT by a technique (MRI-DTI, DTI= Direct Thrombus Imaging) which detects methhaemoglobin (M-Hb) and the initial results are promising.

Reference: Scarsbrook AF et al. Diagnosis of suspected venous thromboembolic disease in pregnancy. Clin Rad 2006: 61: 1-12.