Lung and pleura Flashcards
Lung with large endothelial cells, epithelial cells, and alveolar histiocytes with a prominent basophilic nuclear inclusion, often with a clear halo.
CMV pneumonitis
Differential diagnosis:
CMV pneumonitis with another infection (e.g. fungal, PJP)
Plan:
Correlate with clinical history and radiology (?immunosupression ?CXR/CT findings)
Examine further blocks (for other infectious agents which may be present in immunosupressed patient)
Correlate with any concurrent microbiology testing (?PCR ?Culture) - if not done, send fresh tissue urgently
IPX to support Dx: CMV
Advice to clinician (urgent via phone): This is a life threatening viral infection and may be assiociated with profound immunosupression. Patient should be investigated and treated in hospital.
Lung with alveolar spaces filled with pink, foamy amorphous material composed of cell debris
Pneumocystis pneumonitis
Differential diagnosis:
Alveolar proteinosis
PJP with another infection (e.g. CMV)
Plan:
Correlate with clinical history and radiology (?immunosupression ?CXR/CT findings)
Examine further blocks (for other infectious agents which may be present in immunosupressed patient)
Correlate with any concurrent microbiology testing (?PCR ?culture) - if not done, send fresh tissue urgently
Special stains: GMS (highlight cup shaped fungi), also PAS, Gram, ZN (highlight any concurrent infectious agents)
Advice to clinician (urgent via phone): This is a life threatening fungal infection and may be assiociated with immunosupression. Patient should be investigated and treated in hospital.
Lung with aggregates of cells along bronchioles with lightly eosinophilic cytoplasm and round to oval nuclei with frequent irregularities and grooves. These are frequently admixed with eosinophils. Older nodules progress to fibrotic (often stellate) scars.
Langerhans cell histiocytosis
Plan:
Correlate with clinical history and radiology (?smoking history)
Examine further blocks
IPX to support Dx: S100, CD1a, langerin. Also needs BRAFV600E
Next steps: Synoptic report, discuss at MDT
Advice to clinician: Smoking related, may respond to smoking cessation
Lung with fat cells with or without marrow elements in the pulmonary circulation
Fat embolism
Plan:
Correlate with clinical history and radiology (?major trauma / fracture)
This is likely a post-mortem finding
Lung tumour with ‘organoid’ architecture (includes nests, trabeculae, rosettes, follicules/pseudoglands, etc) of epithelioid to spindled cells cells with eosinophilic cytoplasm and round to oval nuclei with finely granular ‘salt and pepper’ chromatin and inconspicuous nucleoli.
Carcinoid tumour of lung
Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g. for total size of lesion, relation to margins, areas of mitotic activity/necrosis)
IPX to support Dx: AE1/AE3, synaptophysin, chromogranin, Ki67
Next steps: Formal grade, synoptic report, discuss at MDT
Lung tumour with glands of malignant epithelial cells invading fibrous stroma
Lung adenocarcinoma (acinar type)
Differential diagnosis:
Metastatic adenocarcinoma
Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g. for total size, relation to margins, areas of other architectural patterns)
IPX to support Dx: AE1/AE3, CK7/20, TTF1, Napsin A (expect CK7 positive, 20 negative, TTF1 Napsin A positive)
Next steps: PDL1, ALK and ROS1 IHC, lung gene panel, synoptic report, discuss at MDT
Lung with honeycombing interstitial fibrosis with asbestos bodies (golden brown, fusiform or beaded rods with translucent center)
Asbestosis of lung
Differential diagnosis:
UIP/interstitial fibrosis due to other causes (e.g coal, silica, other dusts, idiopathic pulmonary fibrosis)
Plan:
Correlate with clinical history and radiology (?asbestos exposure)
Examine further blocks
Examine under polarised light
Next steps: May require expert review (due to medicolegal nature of Dx), discussion at specialised MDT
Lung with nodules of fibrosis with needle-like silica crystals
Silicosis of lung
Plan:
Correlate with clinical history and radiology (?occupational exposure)
Examine further blocks
Examine under polarised light (expect silica to be birefringent)
Next steps: May require expert review (due to medicolegal nature of Dx), discuss at specialised MDT
Inflammatory lung lesion containing septate fungal hyphae with acute angle branching
Pulmonary aspergillosis
Differential diagnosis:
Aspergillus as part of polymicrobial infection
Plan:
Correlate with clinical history and radiology (?immunosupression ?cavitating lesion)
Correlate with concurrent microbiology investigations - if not done send fresh tissue urgently
Examine further blocks (e.g for other infectious agents which may be present in immunosupressed host)
Special stains: PAS, GMS (expect to highlight fungal hyphae). Also gram, ZN.
Advice to clinician (urgent via phone): This is a serious fungal infection and may be due to immunosuppression. Patient should be investigated and treated in hospital.
Inflammatory lung lesion containing broad, non-septate fungal hyphae with right angle (90 degree) branching
Pulmonary mucormycosis
Differential diagnosis:
Mucormycosis as part of polymicrobial infection
Plan:
Correlate with clinical history and radiology (?immunosupression ?cavitating lesion)
Correlate with concurrent microbiology investigations - if not done send fresh tissue urgently
Examine further blocks (e.g for other infectious agents which may be present in immunosupressed host)
Special stains: PAS, GMS (expect to highlight fungal hyphae). Also gram, ZN.
Advice to clinician (urgent via phone): This is a serious fungal infection and may be due to immunosuppression. Patient should be investigated and treated in hospital.
Lung with lipid droplets and accumulation of foamy macrophages within the alveoli.
Lipoid pneumonia
Plan:
Correlate with clinical history / radiology (?exogenous exposure ?critical illness)
Examine further blocks
This is likely a post-mortem finding
Lung with large, necrotising granulomas with periphery containing multinucleated giant cells (especially Langhans type giant cells with nuclei arranged in a horseshoe pattern)
Pulmonary tuberculosis
Differential diagnosis:
Infection with non-tuberculous mycobacteria
Fungal infection
Granulomatosis with polyangiitis (formerly Wagner’s)
Rheumatoid nodule
Plan:
Correlate with clinical history and radiology (?systemic disease ?ANCA, RF)
Correlate with concurrent microbiology investigations (culture, PCR) - if not done send fresh tissue urgently. If fresh tissue not available, Paraffin block can be used for M. tuberculosis PCR if needed
Examine further blocks
Special stains - PAS, GMS, ZN, Gram. If available, auramine-rhodamine.
Advice to clinician (urgent via phone): This is a serious infection. This patient requires urgent treatment and may require precautions for public safety (public health implications)
Lung with non-necrotising granulomas with a bronchovascular distribution and associated fibrosis. Multinucleated giant cells are present and may contain asteroid or Schauman bodies.
Non-necrotising inflammation suggestive of pulmonary sarcoidosis
Differential diagnosis:
Granulomata due to infectious causes (fungi, atypical mycobacteria)
Foreign body granulomas
Plan:
Correlate with clinical history and radiology (?lymphadenopathy ?infectious/occupational exposure)
Correlate with concurrent microbiology investigations
Examine under polarised light
Special stains: Gram, PAS, GMS, ZN
Highly infiltrative lung lesion with perineural invasion. Predominant myoepithelial cells impart a basaloid appearance. Growth pattern can be tubular, cribriform, or solid. Tumour cells are surrounded by hyalnized reduplicated basement membrane material.
Adenoid cystic carcinoma of lung
Differential diagnosis:
Metastatic adenoid cystic carcinoma (e.g. from salivary gland)
Plan:
Correlate with clinical history and radiology (?Central solitary lung tumour or multiple lesions ?previous adenoid cystic in salivary gland)
Examine further sections (e.g for size, margins, extent of PNI/LVI, pleural involvement etc)
IPX: Not required for diagnosis
Next steps: Synoptic report, discuss at MDT
Lung lesion with variable architecture (papillary, solid, haemorrhagic, and sclerotic areas with hyalinised stroma), composed of bland pneumocytes and round stromal cells. May contain hemosiderin laden macrophages and dystrophic calcification
Sclerosing pneumocytoma
Differential diagnosis:
Carcinoid tumour of lung
Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g. for total size, relation to margins etc)
IPX to support Dx: EMA, TTF1 (expect positive)
IPX to discount DDx: Synaptophysin and chromogranin
Next steps: Synoptic report, discuss at MDT
Well-circumscribed, often lobulated lung tumour composed of mature cartilage, adipose tissue, fibrous tissue, and entrapped respiratory epithelium forming clefts or small glands.
Pulmonary hamartoma
Differential diagnosis:
Pulmonary chondroma (if cartilage only)
