Squamous Carcinoma
Squamous Carcinoma
8; This low power view of lung is centered on a sheet of neoplastic cells outlined by yellow arrows. € The surrounding stroma is composed of desmoplastic fibrotic tissue heavily infiltrated by lymphocytes. € The neoplastic cells show hyperchromatic nuclei and an increased N:C. € Higher power will allow histologic typing.


(Image Contrib. by:UCHC)(Description by: Linda Ernst)
T28000M80703
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Squamous Carcinoma
Etiology

• Most closely associated with cigarette smoking of all lung cancers

• Radiation, air pollution and genetic predisposition may also play a role


Pathogenesis

• BPDE (catabolite of benzo[a]pyrene in cigarette smoke) binds p53 mutational hot spots in lung carcinoma

• p53 mutation affects cell replication and centromere replication

• Sequence of changes from squamous metaplasia to dysplasia to carcinoma in situ and then invasive carcinoma seen.


Epidemiology

• Accounts for up to half of all lung cancers.

• Up to 10% of long term cigarette smokers develop


Clinical

• Central location associated with cough and hemoptysis

• Weight loss and dyspnea

• Staging dependent on extent of disease ranging from I (confined to the lung with >2 cm distance from hilum and pleura) to IV (metastatic disease)

• Metastatic disease to lymph nodes, brain, liver and adrenal glands

• Surgical treatment is preferred; many patients have insufficient pulmonary reserve for surgery; radiation an alternative

• Overall five year survival 10-15%

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General Gross Description

• Usually arises from a major bronchus resulting in a central rather than a peripheral location

• Gray white hard granular neoplasm

• Central cavitation common in large cancers

• Uninvolved lung may often show emphysema or other smoking related pathology


General Micro Description

• Composed of cells with large irregular nuclei

• Coarse nuclear chromatin with large nucleoli

• Cells arranged in sheets

• May make keratin pearls

• Intercellular bridges considered diagnostic


Reference

• Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th edition. Philadelphia, W.B. Saunders, 1994, pp. 720-25.


• Current literature from PubMed at National Library of Medicine


Synopsis by: Melinda Sanders M.D., UCHC
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