it is a common tumor of male paratesticular tissues ( epididymis , tunica or spermatic cord ) and has also been described in females ( uterus , fallopian tube , ovary and paraovarian tissues ) .
the majority of these tumors are asymptomatic and presents as a mass in the genital area , which is worrisome to both patient and clinician and requires a definitive diagnosis to rule out malignancy ( 2 ) .
fnac is a rapid , reliable and cost effective diagnostic tool for preoperative diagnosis of paratesticular swellings .
we report a case of epididymal adenomatoid tumor diagnosed on aspiration cytology , which was confirmed on histopathology and immunohistochemistry .
a 24 year old male presented with progressively increasing painless swelling of the right epididymis for 2 months .
local examination revealed a firm , mobile , mildly tender mass measuring 1.5x1.5 cm in diameter in the right epididymis .
ultrasonography of the swelling revealed a well - defined hypoechoic lesion of 18x11 mm , with increased flow on color doppler ( figure 1 ) .
well defined hypoechoic lesion of size 18x11 mm in right epididymis ( white arrow ) and normal right testis ( black arrow ) fine needle aspiration of the swelling was performed using a 23-gauge needle and 10 ml syringe .
examination of the smears revealed cells arranged in loose aggregates in a vaguely glandular pattern and singly scattered at places along with stromal fragments and a few inflammatory cells in a haemorrhagic background .
the cells have ovoid , vesicular nuclei , finely granular and evenly distributed chromatin , small nucleoli and abundant cytoplasm with vacuolization at places ( figure 2 ) .
stromal cells ( romanowsky x 200 ) the patient underwent a conservative testis sparing surgery with the excision of epididymal nodule .
the nodule measured 1.5x1.2 cm in diameter and the cut section was gray - white .
histopathology revealed some slit like or glandular spaces lined by flattened cells with intracytoplasmic vacuoles in an abundant fibromuscular stroma and few inflammatory cells . on immunohistochemistry tumor cells were positive for mesothelial marker calretinin and negative for cd34 , factor - viii and cea .
photomicrograph showing a ) histopathological features of adenomatoid tumor consisting of dilated tubular structures lined by cuboidal to flattened epithelial cells ( h and e x 200 ) .
adenomatoid tumor(at ) . is the most common benign tumor of paratesticular tissue and accounts for 32% of all tumors in this location ( 3 ) .
the term adenomatoid tumor was first coined by godman and ash in 1945 ( 4,5 ) . besides the epididymis
, adenomatoid tumor can be located in the spermatic cord , prostrate , ejaculatory ducts and scrotal capes and in females it can be located in uterus , fallopian tubes and ovaries ( 6 ) . it is common in the 3rd and 4th decades of life ( 4,6,7 ) .
most of these are asymptomatic and are noticed incidentally by the patient or by the physician on physical examination , as a painless intrascrotal mass .
it presents as a relatively small , well demarcated uncapsulated nodule , usually less than 2 cm in diameter .
the histogenesis of at has been a matter of debate for many years with the proposed cells of origin being endothelial , mesothelial , mesonephric , mullerian and epithelial ( 8) . though the structural and immunohistochemical studies support the mesothelial origin , the usual coexistence of chronic inflammatory cells and fibrosis suggests mesothelial hyperplasia ( 6,8 )
. the first cytological description of at was described by perez - guillemro et al in 1989 ( 2 ) .
adenomatoid tumors have been described briefly in textbooks on fna cytology and only a few cases of this entity diagnosed by fnac are recorded in the literature ( 2,5 ) . on fine needle aspiration cytology
adenomatoid tumors reveal abundant cellularity and comprise sheets and multilayered clusters of monotonous cells with round or ovoid , eccentric nuclei containing small central nucleoli . paranuclear clearing with a pink colouration ( giemsa stain ) . or a clear vacuole like area ( papanicolaou stain ) with a background of naked nuclei and stromal fragments ( 2 ) .
the cytological differential diagnosis include reactive mesothelial hyperplasia , papillary cystadenoma , spermatic granuloma , malignant mesothelioma and metastatic adenocarcinoma ( 4,5 ) .
reactive mesothelial cells with hyperplasia can be seen in hydrocoele fluid , the cells show anisocytosis and pleomorphism and have a moderate amount of pale cytoplasm .
they may not have definite arrangement of cells , a feature seen distinctly in adenomatoid tumors .
cytologically papillary cystadenoma comprises of papillary structures and single isolated cells without nuclear atypia and with cytoplasmic vacuoles in a mucoid background .
malignant mesothelioma show a diffuse cell pattern with cells having ruffled borders with dense cytoplasm , nuclear enlargement , macronucleation and multinucleation .
metastatic adenocarcinoma show cytological features of malignancy and cells are positive for mucicarmine ( 4,5 ) . on histopathology
, the tumor has a plethora of microscopic appearances , with proliferation of cells ranging from cuboidal to flattened , which forms solid cords with an epithelial appearance alternating with channels having dilated lumina simulating vascular structures
. the prominent intervening stroma may contain abundant smooth muscles and elastic fibres ; it may also have a reactive desmoplastic quality and be infiltrated by inflammatory cells .
on immunohistochemistry these cells are positive for mesothelial related markers ( calretinin , hmbe1 ) . and negative for cea and factor viii related antigen ( 6,7 ) .
ultrasonography along with cytological features helps to make a definite diagnosis and to evolve an organ sparing surgical approach ( 4 )
the preoperative cytology may be used as an important diagnostic tool to evaluate the paratesticular masses .
pathologist should be aware of cytological features of these common lesions to avoid aggressive or unnecessary surgical procedures .
 adenomatoid tumor is a benign mesothelial neoplasm of the paratesticular region in males but can also occur in female genital tracts . 
 the epididymis is the most common site of involvement and constitutes 32% of paratesticular neoplasms.we diagnosed a case of adenomatoid tumor on cytopathology in 24 years old male , who presented with mass lesion right epididymis since 2 months . 
 the diagnosis was confirmed on histopathology and immunohistochemistry after surgical excision of the nodule.fnac is a rapid , reliable and cost effective diagnostic tool for preoperative diagnosis to take appropriate surgical decisions . 
 pathologists should be aware of the cytological features of such lesions so as to differentiate it from other paratesticular lesions . 
INTRODUCTION
CASE REPORT
DISCUSSION