Lung tumours
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Lung cancer comes to pathology to get diagnosed.
Lung tumours overview
Schematic overview of lung cancer (clinical)
| Lung cancer | |||||||||||||||||||||||||||||||||||||||||
| Primary | Metastatic | ||||||||||||||||||||||||||||||||||||||||
| NSCLC | SCLC | ||||||||||||||||||||||||||||||||||||||||
- NSCLC = non-small cell lung cancer.
- SCLS = small cell lung cancer.
Basic pathologic approach to lung cancer
| Lung cancer | |||||||||||||||||||||||||||||||
| Adenocarcinoma | Squamous cell carcinoma | SCLC | LCLC | ||||||||||||||||||||||||||||
- LCLC = large cell lung cancer.
- SCLS = small cell lung cancer.
Notes:
- Most lung cancer fits into one of the above categories.
- All types may be metastatic. Pathologists usually don't have to sort this out, as the clinican often knows whether a given lesion is metastatic (when correlated with radiology).
- Lung cancers may have a mixed morphology, e.g. SCLS may have squamous component.[1]
Major types (primary)
Mnemonic ASSL:
- Adenocarcinoma.
- Squamous cell carcinoma.
- Small cell carcinoma (SCLC).
- Large cell carcinoma (LCLC).
Epidemiology
- Adenocarcinoma is the most common (primary lung cancer).[2]
- Adenocarcinoma is the non-smoker tumour - SCLC and squamous are more strongly associated with smoking.
Distribution
- Distribution - think about the location of letters in mnemonic ASSL.
- Adenocarcinoma is usually periperal, i.e. smaller airways.
- Squamous cell carcinoma and small cell carcinoma are typically central.
Management of primary lung cancer
Management is currently determined by categorization into:
- Small cell cancer.
- Non-small cell cancer (includes adenocarcinoma, squamous cell carcinoma, large cell carcinoma).
Microscopic features overview
Adenocarcinoma
- Glands or cytoplasm with mucin.
Squamous cell carcinoma
- Distinct cell borders with intercellular bridges.
- Eosinophilic cytoplasm.
Small cell carcinoma
- Very cellular.
- Large NC ratio - very small amount of cytoplasm.
- Cells fragile - they tend to look "smudged" (Azzopardi phenomenon).
IHC
There is a great review paper by Jagirdar.[3]
Small cell carcinoma
- CD56 +ve - sensitive.[4]
- CK7 -ve, CK20 -ve.
Note:
- CD56 - cytoplasmic.[5]
Squamous cell carcinoma
- CK7 -ve, CK20 -ve.
- HMWK +ve.
- Usually TTF-1 -ve.[6]
Primary vs. secondary
- TTF-1 is considered useful.[3]
- 75% +ve adenocarcinoma
- 11% +ve SSC
- 50% +ve large cell carcinoma
- 0% +ve mesothelioma
- significant rates of +ve in some metastatic tumours -- see article by Jagirdar.
Note:
- TTF-1 - should be nuclear staining; cytoplasmic staining is non-specific.[7]
Mesothelioma
Locations
- Lung.
- Primary peritoneal.
Epidemiology
- Associated with asbestos exposure.
Microscopy
- Ferruginous body (AKA asbestos body).[8]
- Made of asbestos fiber.
- Looks like a (twirling) baton.
Images:
IHC
- Several panel exists - no agreed upon best panel.[9]
- Usually two carcinoma markers + two mesothelial markers.
Panel:[9]
- Mesothelial markers:
- Calretin.
- WT-1.
- D2-40.
- CK5/6.
- Carcinoma markers:
- CEA.
- TTF-1.
See also
- Lung - introduction to the lung, includes a basic approach.
- Medical lung disease.
- Thyroid.
- Basics.
- Heart.
References
- ↑ NEED REF. ???PBoD???
- ↑ Lutschg JH (January 2009). "Lung cancer". N. Engl. J. Med. 360 (1): 87-8; author reply 88. doi:10.1056/NEJMc082208. PMID 19118313.
- ↑ 3.0 3.1 Jagirdar J (March 2008). "Application of immunohistochemistry to the diagnosis of primary and metastatic carcinoma to the lung". Arch. Pathol. Lab. Med. 132 (3): 384-96. PMID 18318581. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=132&page=384.
- ↑ Hiroshima K, Iyoda A, Shida T, et al (October 2006). "Distinction of pulmonary large cell neuroendocrine carcinoma from small cell lung carcinoma: a morphological, immunohistochemical, and molecular analysis". Mod. Pathol. 19 (10): 1358-68. doi:10.1038/modpathol.3800659. PMID 16862075.
- ↑ URL: http://jcp.bmjjournals.com/content/58/9/978.full. Accessed: 11 February 2010.
- ↑ Al-Zahrani IH (July 2008). "The value of immunohistochemical expression of TTF-1, CK7 and CK20 in the diagnosis of primary and secondary lung carcinomas". Saudi Med J 29 (7): 957-61. PMID 18626520.
- ↑ Compérat E, Zhang F, Perrotin C, et al. (October 2005). "Variable sensitivity and specificity of TTF-1 antibodies in lung metastatic adenocarcinoma of colorectal origin". Mod. Pathol. 18 (10): 1371–6. doi:10.1038/modpathol.3800422. PMID 15861215. http://www.nature.com/modpathol/journal/v18/n10/full/3800422a.html.
- ↑ http://medical-dictionary.thefreedictionary.com/asbestos+body
- ↑ 9.0 9.1 Marchevsky AM (March 2008). "Application of immunohistochemistry to the diagnosis of malignant mesothelioma". Arch. Pathol. Lab. Med. 132 (3): 397-401. PMID 18318582. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=132&page=397.