Differentials Flashcards
Differential diagnosis for multiple round pulmonary lesions in elderly patient?
V - Mulitple AVMs = hereditary haemorrhage telangiectasia
I - Abscesses, (s. aureus), histo, hydatid
T - N/A
A - Wegener’s, rheumatoid, progressive massive fibrosis
M
I - N/A
Neoplastic: Metastases, Breast, thyroid, kidney, GI - lower lobes. Multiple synchronous lung cancers, benign metastasing tumours - fibroids, meningiomas, pleomorphic adenomas
Congenital: -
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Causes of centrilobular micronodules
Infection: Viral, mycobacterial
Aspiration
Inflammation - hypersensitivity pneumonitis, respiratory bronchiolitis
Causes of tree-in-bud micronodules
Issue affecting the bronchi, vessels or axial interstitium
Infection –> bronchiolitis:
- Mycobacterial
- Viral
- Bacterial pneumonia
- Aspiration
Neoplastic
- Endovascular met - breast, stomach
- Lymphangitis carcinomatosis
Connective tissue disorders - RA, Sjogren’s
Inflammatory: Bronchiolitis obliterans (post-transplant), diffuse pan-bronchiolitis (Asians), follicular bronchiolitis (BALT)
Congenital - CF, immotile cilia syndrome
Causes of diffuse cystic lung disease
- Pulmonary Langerhans cell histiocytosis (young adults, cigarettes) - sparing of lower lobes and medial middle lobe/lingula - “costophrenic sulci”
- LAM - women of childbearing age - multiple cysts, no zonal predilection
- Tuberous sclerosis
- Birt-Hogg-Dube - low lobe predominant, cigar shaped cysts
Causes of non-diffuse cystic lung disease
V - N/A
I - Post-infective:
- Bacterial pneumonia (staph aureus, strep)
- Pneumocystis jirovecii
- Hydatid cyst (fluid filled, air)
T - Post-traumatic:
- Lung laceration
A, M, I - N/A
Neoplastic:
- Post treatment of lung mets
- Cystic lung metastases - colonic, subtypes of sarcoma
Congenital:
- CPAM - single multi-loculated cyst
- Bronchogenic cyst
Cavitating lung lesions (gas-filled space within mass/nodule/consolidation)
Vascular
- Infarction - apical predominance - compared to lower segment predilection of non-cavitating infarcts
Infective:
- Staph aureus/Klebsiella
- TB
- Septic emboli
- Aspiration - associated with foreign body e.g. tooth
- Infection of pre-existing bulla/cyst/sequestration
- Hydatid, amoebiasis
Trauma:
- Haematoma, traumatic lung cyst
Autoimmune/inflammatory:
- Wegener’s granulomatosis
- Rheumatoid nodules
- Sarcoidosis - later stages
Metabolic:
Iatrogenic: N/A
Neoplastic:
- Lung cancer - predilection for UL - more common in SCC
- Metastases - SCC, colon, sarcoma
- Lymphoma
Congenital: N/A
Miliary distribution of micro-nodules
Soft tissue density:
- Infection: Miliary infections (TB or fungal (crypto, histo))
- Papillary thyroid carcinoma
- Sarcoidosis - upper zones (fibrosis/bronchiectasis), hilar adenopathy
- Pneumoconioses - coal worker’s
High-than soft tissue density
- Healed varicella infection
- Haemosiderosis
- Silicosis - sparing of bases and apices
Fibrosing mediastinitis differentials, how to distinguish?
DDx are malignancies - Low T2 on MRI can be useful to differentiate from these
Can be indistinguishable from sclerosing non-Hodgkin’s lymphoma in the absence of
Solitary pulmonary lesion differentials
Vascular: AVM
Infection: Granuloma (TB, histo), round pneumonia, hydatid,
Trauma: Haematoma
Autoimmune: Wegeners, RA
Metabolic: N/A
Iatrogenic: N/A
Neoplastic: Benign (Hamartoma, carcinoid) or malignant (lung primary or solitary met)
Congenital: LN, bronchopulmonary sequestration, bronchogenic cyst
Upper zone predominant fibrosis
Old TB
Silicosis/pneumoconiosis
Chronic hypersensitivity pneumonitis
Radiation
Ankylosing spondylitis
Pleuroparenchymal fibroelastosis
Causes of upper zone bronchiectasis
CF
TB
Causes of mid-zone bronchiectasis?
Non-tuberculous mycobacterial infection
Middle lobe syndrome in children
Causes of central bronchiectasis?
ABPA
Tracheobronchomegaly - Mounier Kuhn syndrome
CF
Cases of lower-zone bronchiectasis?
Aspiration/Post-infective
Primary ciliary dyskinesia
Immunodeficiency: Hypogammaglobulinaemia
