Eachoftheselungcancersubtypestendstospreadtolymphnodesinthecarina,themediastinum,andtheneck(scalenenodes)andclavicularregions,and,soonerorlater,todistantsites.Involvementoftheleftsupraclavicularnode(Virchownode)isparticularlycharacteristicandsometimescallsattentiontoanoccultprimarytumor.Thesecancers,whenadvanced,oftenextendintothepleuralorpericardialspace,leadingtoinflammationandeffusions.Theymaycompressorinfiltratethesuperiorvenacavatocausevenouscongestionorthevenacavalsyndrome.Apicalneoplasmsmayinvadethebrachialorcervicalsympatheticplexus,causingseverepaininthedistributionoftheulnarnerveorHornersyndrome(ipsilateralenophthalmos,ptosis,miosis,andanhidrosis).SuchapicalneoplasmsaresometimescalledPancoast tumors, andthecombinationofclinicalfindingsisknownasPancoast syndrome. Pancoasttumorisoftenaccompaniedbydestructionofthefirstandsecondribsandsometimesthethoracicvertebrae.Aswithothercancers,tumor-node-metastasis(TNM)categoriesareusedtoindicatethesizeandspreadoftheprimaryneoplasm.
Carcinomas of the lung are insidious lesions that in many cases have spread so as to be unresectable before they produce symptoms. In some instances chronic cough and http://ebooksmedicine.net
Fig. 13.44 Precursorlesionsofsquamouscellcarcinomas.(AtoC)Someoftheearliest(and“mild”)changesinsmoking-damagedrespiratoryepitheliumincludegobletcellhyperplasia(A),basalcell(orreservecell)hyperplasia(B),andsquamousmetaplasia(C).(D)Moreominouschangesincludetheappearanceofsquamousdysplasia,characterizedbythepresenceofdisorderedsquamousepithelium,withlossofnuclearpolarity,nuclearhyperchromasia,pleomorphism,andmitoticfigures.(EandF)Squamousdysplasiamay,inturn,progressthroughthestagesofmild,moderate,andseveredysplasia.Carcinomainsitu(CIS) (E)isthestagethatimmediatelyprecedesinvasivesquamouscellcarcinoma(F).ApartfromthelackofbasementmembranedisruptioninCIS,thecytologicfeaturesofCISaresimilartothoseinfrankcarcinoma.(AtoE,Courtesy of Dr. Adi Gazdar, Department of Pathology, University of Texas Southwestern Medical School, Dallas,Texas. F,Reproduced with permission from Travis WD,Colby TV,Corrin B,et al,editors: WorldHealthOrganizationhistologicaltypingoflungandpleuraltumors,Heidelberg, 1999, Springer.)
Fig. 13.45 Squamouscellcarcinoma.(A)Squamouscellcarcinomaappearingasacentral(hilar)massthatisinvadingcontiguousparenchyma.(B)Well-differentiatedsquamouscellcarcinoma,showingkeratinizationandpearls.
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Fig. 13.46 Smallcellcarcinomawithsmalldeeplybasophiliccellsandareasofnecrosis(top left). Notebasophilicstainingofvascularwallsduetoencrus-tationbyDNAfromnecrotictumorcells(Azzopardieffect).