fine needle aspiration cytology ( fnac ) is a rapid and convenient method of diagnosing any accessible lesion .
however , there are some tumors like malignant round cell tumors , which always pose a diagnostic problem to a pathologist . for quick diagnosis of such lesions ,
if fnac and icc are used properly , a quick and correct guideline can be provided to the clinicians for selecting the right protocol for treatment , avoiding immediate surgical intervention and thus save additional expense and time .
apart from fnac smears , icc can be done on smears prepared from centrifuged cell deposits obtained from body fluids and cells grown in culture .
the study was carried out in the departments of pathology in our institutes from june 2008 to june 2011 .
seventy eight cases of patients presenting with tumors of various sites were selected who attended the out - patient department in our institutes .
, fnac was done in all cases and the diagnosis was given as either malignant round cell or undifferentiated neoplasm .
all 78 cases were subjected to histopathological evaluation , special stains ( periodic acid schiff , reticulin ) and immunohistochemistry .
fnac was performed by 10 ml syringe with a 22 g or 24 g needle following the standard technique and the smears were stained by leishman - giemsa and hematoxylin and eosin or papanicolaou ( pap ) stains .
monoclonal antibodies to pancytokeratin , ck7 , ck20 , leucocyte common antigen , desmin , vimentin , cd3 , cd20 , cd30 , neurone specific enolase , chromogranin a , cd99 , terminal deoxynucleotidyl transferase , ttf 1 , bcl 2 , cd117 and others along with novolink polymer detection kit by novocastra ( uk ) were selectively used depending on the case .
the icc protocol was as follows : first the slide was washed in tris buffered saline ( tbs , 0.005 m , ph 7.6 ) , 10 min each for 3 changes . then the slide was treated with 3% hydrogen peroxide in methanol for 10 min ( peroxidase blocking ) ,
then again washed in tbs ( as before ) , followed by protein blocking for 10 min .
then it was incubated with primary antibody ( pre diluted ) at room temperature in moist chamber for 1 h. it was then washed in tbs ( as before ) .
then it was treated with polymer for 30 min , which was followed by washing in tbs ( as before ) .
it was then treated with prepared dab -chromogen for 5 - 10 min ( till appearance of brown color ) .
then after washing in distilled water , counterstaining was done with hematoxylin for 1 min .
then it was washed under running tap water followed by graded dehydration in alcohol , cleared in xylene and mounted with dpx .
of the 78 cases , 51 ( 65.3% ) were plain , 17 ( 21.8% ) were computerized tomography ( ct ) guided and 10 ( 12.8% ) were ultrasonography ( usg ) guided fnacs respectively .
of these we could perform icc in only 36 ( 46.1% ) cases . of the 36 cases of study group ,
plain fnac was done in 21 ( 58.3% ) cases , ct guided fnac in 10 ( 27.8% ) cases and usg guided fnac in 5 ( 13.9% ) cases [ table 1 ] .
number of cases with type of approach patients age varied from 2.5 years to 76 years .
our diagnosis by icc on fna smears was confirmed by histopathological evaluation as well ase immunohistochemitry when required [ figures 1 and 2 ] .
the diagnosis correlated in 30 ( 88.9% ) cases but did n't match in 4 ( 11.1% ) cases , because they were either inadequate or necrotic smears or showed equivocal staining with more than one antibody .
rhabdomyosarcoma : ( a ) computerized tomography scan , pns mass , 9-year - old boy ; ( b ) fine needle aspiration cytology smears ( lg , 400 ) ; ( c ) cytology smears stained with desmin ( icc , 400 ) ; ( d ) sections stained with desmin ( ihc , 100 ) non - hodgkin 's lymphoma . (
a ) clinical photograph showing a fungating breast mass ; ( b ) fine needle aspiration cytology smears ( lg stain 100 ) ; ( c ) cytology smears stained with cd45 ( icc , 100 ) ; ( d ) sections stained with cd45 ( ihc , 100 ) lesions according to most common sites- was head and neck 11 ( 30.5% ) , then soft tissue 10 ( 28% ) , lung 08 ( 22% ) , breast 02 ( 5.5% ) , mediastinum 02 ( 5.5% ) , ovary 02 ( 5.5% ) and urinary bladder 01 ( 03% ) respectively [ table 2 ] .
comparison of immunocytochemistry with immunohistochemistry sensitivity of this study was 93% , specificity 83% and accuracy 92% respectively .
definite diagnostic criteria in different lesions using fnac was first applied by zajicek and immunostaining method using enzymes as labels was first used by nakane and pierce in 1966 .
one of the most popular recent techniques streptavidin - biotin technique was first used by guesdon et al . in 1979 .
undifferentiated neoplasms very often pose diagnostic problem to pathologists specially when only fnac is used as a diagnostic tool .
abendroth and dabbs , used immunoperoxidase staining with selected antibodies in 75 cases of smears made from various neoplastic or non - neoplastic tissues received as surgical specimens .
dabbs and wang also used more than one antibody on a single pap stained slide to prove the use of icc on limited smears .
used icc on fnac smears to confirm the diagnosis of 51 cases of malignant small round cell tumors .
however , icc may have some inherent problems and may give false positive or false negative results .
causes of false positive staining may be due to insufficient peroxidase blocking , necrotic cells , dried preparation , cross reactivity of antibodies .
false negative results may be due to low antibody concentration , denaturation of aspirated material etc . ,
last but not the least , in both the categories there is misinterpretation of neoplastic and reactive cells by the cytopathologist .
these problems may be resolved to some extent by use of cell block preparation . however , even icc on cell block may not have 100% diagnostic accuracy . moreover , processing time for cell block preparation ( like small biopsy ) and subsequent icc may be more time consuming compared to icc on smears .
it is less time consuming ( report is ready within 24 h ) and a cheap outdoor procedure . as the number of specimen is somewhat limited , conventional light microscopy should not be ignored for judicious selection of antibodies .
icc can thus be established as a routine technique in the diagnosis of undifferentiated tumors .
 background : fine needle aspiration cytology ( fnac ) is a rapid , cheap and reliable method for diagnosing any accessible lesion . 
 however , there remains a group of malignant undifferentiated neoplasms , which can only be categorized with the help of immunocytochemistry ( icc ) . 
 the categorization is important due to their vast difference in treatment and prognosis.aim:to evaluate the effectiveness of icc in categorizing the undifferentiated neoplasms diagnosed on routine fnac smears.materials and methods : thirty six cases of undifferentiated neoplasms were selected from a group of total 78 cytology cases of undifferentiated tumors from different sites like head and neck , lymph node , soft tissue etc . 
 these were then subjected to a panel of icc markers based on the clinical and cytomorphological features.results:of these , 21 were simple , ten were computerized tomography guided and five were ultrasound guided fnacs respectively . 
 all the 78 cases were confirmed by histopathological examination and immunohistochemistry . 
 of the 36 cytological cases , final diagnosis correlated in 30 cases histologically . 
 the six cases were incorrect either due to inadequate material on the smears ( three cases ) or false positive staining ( three cases).conclusions : our study found that icc is a sensitive and specific method for early and definitive diagnosis of undifferentiated neoplasms 
 . however , selection of antibodies must be judicious to make it cost effective . 
Introduction
Materials and Methods
Results
Discussion
Conclusions