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Examination of lobectomy or pneumonectomy specimens
for neoplasia:
Indication:
-
To determine the histological type of a lung tumour
which is easier on large
specimen than on biopsy material.
Examination of lobectomy specimens
for non-neoplastic diseases:
Indication:
- Cysts
(congenital or acquired, secondary to emphysema or inflammation) and
inflammatory lesions such as bronchiectasis, bullae and
sequestrations.
- Sometimes for
localized areas of consolidation and organizing pneumonia,
inflammatory pseudotumour,
Wegener’s granulomatosis and rheumatoid nodule.
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Malignant Lung Tumours:
Primary lung
carcinomas can be classified as squamous cell carcinoma,
adenocarcinoma, small cell carcinoma, large cell carcinoma and giant
cell carcinoma.
Small cell
carcinomas are usually too advanced for treatment by surgery and are,
therefore, not seen in excision specimens.
Pure large cell
and giant cell carcinoma are diagnosed only after features of squamous
and glandular differentiation have been excluded.
Clear cell change
may be a feature of any type of carcinoma.
Some carcinomas
show mixed differentiation (adenosquamous carcinomas), combination of
malignant epithelial and mesenchymal elements (carcinosarcomas and
pulmonary blastomas) or spindle cell areas.
Some show such a
degree of pleomorphism that classification is not possible.
Primary sarcomas of
the lung are rare. The most commonly seen include leiomyosarcoma and
rhabdomyosarcoma.
Pulmonary
lymphomas are treated by chemotherapy rather than excision.
Benign
tumours and tumor-like conditions:
These are most
commonly excised from asymptomatic patients after incidental findings
on chest radiography.
These include benign mesenchymoma (pulmonary hamartoma), inflammatory
pseudotumor, sclerosing hemangioma and nodular amyloidosis.
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An approach
to histopathological reporting of lobectomy specimens:
I) Neoplasia:
The report
should contain the following information:
- Histological type and degree of differentiation:
(i) Squamous cell carcinoma ;
(ii) Adenocarcinoma ;
(iii) Large cell
carcinoma ;
(iv) Giant cell carcinoma,
- Features important for staging:
(Involvement of bronchial resection margin;
involvement of pleura; vascular invasion; involvement of lymph nodes).
- Features in the lung away from the
neoplasm:
Squamous metaplasia, dysplasia, or in situ
malignancy in bronchial epithelium ; Obstructive pneumonitis with the features of
endogenous lipid pneumonia ; Sarcoid-like granulomas in the lung and lymph
nodes ; Asbestos bodies.
- Preexisting lung disease:
Emphysema ; Desmoplasia ;
Non-fibrotic changes in the alveoli
(hyaline membrane
formation ; interstitial inflammation, hyperplasia of
alveolar lining cells).
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Important features in specific tumour:
(Carcinoid tumour:
high mitotic rate and necrosis are
associated with aggressive behaviour (atypical carcinoid), nuclear
pleomorphism alone is not a reliable indicator; Spindle cell morphology, oncocytic
change, and melanin pigment;
Adenoid cystic
carcinoma:
spread in the walls of airways, and
involvement of perineural spaces).
(II) Non-neoplastic
lesions:
- Cystic and cavitating
lesions:
Contents of cavity:
Pus in lung abscess; aspirated foreign material; caseous material in tuberculosis; mycetoma
- usually aspergilloma ;
Lining epithelium:
Respiratory, squamous, enteric, mucinous ; squamous epithelium in re-epithelialization
of a cavity ;
Cyst wall:
Granulation tissue with
fibrosis ; Bronchial seromucous glands and cartilage
in bronchogenic cyst; Pancreatic tissue and mucous glands in
enteric cysts ; Multiple cysts lined by respiratory
epithelium in adenomatoid malformations; Focal granulomatous malformation with
scattered giant cells in mycetoma; Necrotizing granulomas with caseation
necrosis in mycobacterial infection; Mycetoma formation associated with other
diseases such as tuberculosis, emphysema with bulla formation
and late stage sarcoidosis with fibrosis.
- Inflammatory lesions:
Lumen of
bronchi and bronchioles:
Pus in cystic fibrosis ;
Mucus plugging in allergic bronchopulmonary aspergillosis ; Fungal hyphae within mucus in allergic
bronchopulmonary aspergillosis and as mycetoma in
complicated bronchiectasis ; Bacterial colonies (botryomycosis) ;
Eosinophils in allergic bronchopulmonary
aspergillosis.
Epithelium:
Mucinous metaplasia in cystic fibrosis ;
Squamous metaplasia in bronchiectasis
and non-specific inflammatory conditions ; Ulceration and replacement by
granulation tissue in bronchiectasis and allergic bronchopulmonary
aspergillosis.
Bronchial wall:
Non-specific inflammation with fibrosis
in bronchiectasis ; Follicular lymphoid aggregates in
follicular bronchiectasis ; Granulomatous inflammation with
numerous histiocytes , scattered giant cells, and eosinophils in allergic
bronchopulmonary aspergillosis/ bronchocentric
granulomatosis.
Lung parenchyma:
Non-specific
inflammation and fibrosis with organizing pneumonia in bronchiectasis ; mucus plugging in obstructive pneumonitis
; carcinoid tumorlets associated with
bronchiectasis ; necrotizing granulomas with
caseation necrosis in mycobacterial infection ; coagulative fibrinoid necrosis in
the centre of a rheumatoid nodule ; vasculitis in Wegener’s
granulomatosis ; vascular infiltration with
atypical lymphoid cells in angiocentric lymphoma.
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