a primary transitional cell carcinoma ( tcc ) of the ovary is rare and recently recognized subtype of ovarian surface epithelial - stromal cancer . criteria for diagnosis and especially spectrum of its morphology are not clearly established because studies of its morphology are few . the recognition of such tumor is important because of a favorable response to chemotherapy than other surface epithelial cancers . physical examination revealed firm to hard abdominal mass ( 15 cm  12 cm ) with an irregular surface and restricted mobility . , the hard mass was felt through all fornices , more on the right side and infiltrated the anterior rectal wall . computed tomography ( ct ) scan of abdomen and pelvis showed a well - defined , lobulated mass ( 10.7 cm  10.4 cm  12 cm ) in the right pelvis with heterogeneous enhancement . surgical specimens of tumor mass and uterus , cervix , left fallopian tube with ovary and a segment of large intestine ( 9 cm ) were received separately . 12 cm  10 cm ) had lobulated external surface ; the cut section was white mostly solid with few cystic areas [ figure 1a ] . ( b ) undulated bands of pseudostratified neoplastic epithelial cells resembling transitional epithelium separated by the variable amount of necrotic material and fibrovascular tissue . ( d ) tumor cells in solid sheets ( h and e , 100 ) . ( e ) micro spaces and ( f ) mitotic figures ( h and e , 400 ) microscopy of the tumor sections showed elongated bands of pseudostratified neoplastic epithelial cells resembling transitional epithelium separated by the variable amount of necrotic material and fibrovascular tissue [ figure 1b ] . papillae with fibrovascular core lined by similar neoplastic cells were seen [ figure 1c ] . tumor cells arranged in solid sheets , traversed by delicate fibrovascular septa were seen [ figure 1d ] . numerous well - demarcated , small , and empty micro spaces were seen in the bands of the neoplastic epithelium [ figure 1e ] . tumor cells were relatively monomorphic with a round to oblong nuclei and many showing nucleoli . on immunohistochemical ( ihc ) staining , tumor cells were cytokeratin 7 ( ck7 ) , ck20 negative [ figure 2a and b ] and wilms tumor protein-1 ( wt1 ) ( a ) cytokeratin 7 , ( b ) cytokeratin 20 negative and ( c ) wilms tumor protein-1 positive ( ihc , 100 ) primary tcc of the ovary was first described by austin and norris in which definite urothelial features are present but no benign , metaplastic and/or proliferating brenner tumor can be identified . pure forms of the tcc ovary account for only 1% of surface epithelial carcinomas , mixed carcinomas with a predominant tcc for 5% and those with minor tcc component for 3% . much of the interest in tcc of ovary has been focused on whether it has independent prognostic or therapeutic significance while others focused on its ihc profile . although its morphologic features have been described , the overall literature on this aspect is limited . it has a better prognosis than all other types of ovarian carcinoma following standardized chemotherapy . some investigators believe , variation in the interpretation of morphologic features is one possible explanation for better prognosis and response to chemotherapy than other ovarian carcinomas . clinical presentation of tcc is indistinguishable from other types of ovarian carcinomas . it is important to recognize tcc because it is uncommon ; there is some overlap in its morphology with that of the other surface epithelial carcinomas and improved patient survival after a favorable response to chemotherapy . the 1999 ( world health organization ) described tcc as an invasive tumor that lacks a component of benign brenner tumor and is characterized by the presence of papillae lined by malignant cells of transitional cell type or nests of such cells in the fibrous stroma . silva et al . suggested  thick papillary proliferations , a smooth luminal border and projection into empty spaces  are the requirements for a diagnosis of tcc . another less common but distinctive feature they observed was the presence of micro spaces in neoplastic epithelium . the most frequent histological features observed were , undulating thick bands of cells lining the cysts ( 93% ) followed by micro spaces ( 87% ) large cystic spaces ( 73% ) , large blunt papillae ( 63% ) , necrosis ( 57% ) , slit - like fenestrations ( 49% ) , bizarre giant cells ( 35% ) , small filiform papillae ( 18% ) , gland - like spaces ( 17% ) , squamous differentiation ( 13% ) , and psammoma bodies ( 4% ) . in our case , bizarre giant cells , gland - like spaces , squamous differentiation , and psammoma bodies were not seen . features observed by eichhorn and young such as large eosinophilic nucleoli ( 69% ) and longitudinal grooves ( 48% ) were not seen prominently in our case . metastatic tcc from the bladder should be differentiated from primary ovarian tcc for appropriate treatment choice which is usually facilitated by clinical findings . ihc staining may be also helpful . in ihc studies , authors emphasized : ( 1 ) the presence of ck7/ck20 always indicate a urinary tract origin , ( 2 ) ovarian tcc are negative for ck20 , thrombomodulin , and uroplakin , vimentin , ca-125 , wt1 are positive in primary ovarian tcc . found primary ovarian tcc was positive for ck7 , ca-125 , and negative for ck20 . in our case , when the tumor has extensive slit - like manifestations and giant cells , a problem can occur in differentiating from poorly differentiated serous carcinoma and undifferentiated carcinoma . neoplastic cells recognizable as transitional cells , papillae , and thick bands of neoplastic cells of the same type and micro spaces favor the diagnosis of primary tcc of the ovary . higher survival rates can be achieved by surgical resection followed by cisplastin - based chemotherapy . neoplastic epithelial cells recognizable as transitional epithelium arranged in well - demarcated bands from the cystic spaces , papillary projections , and micro spaces within neoplastic epithelium are important histological features .
primary transitional cell carcinoma ( tcc ) of the ovary is a rare and recently recognized subtype of ovarian surface epithelial - stromal cancer . 
 pure forms of the tcc ovary account for only 1% of surface epithelial carcinomas . 
 the clinical presentation is indistinguishable from other types of ovarian cancers . 
 they have a favorable response to chemotherapy than other surface epithelial cancers . 
 we report a case of 55-year - old woman who presented with a hard mass in the abdomen . computed tomography - diagnosed it as a carcinoma of the ovary . 
 tumor was immunoreactive with wilms tumor protein-1 and nonreactive with cytokeratin 7 ( ck7 ) and ck20 . 
 histopathology diagnosis of primary tcc of the ovary was made . 
 these tumors are needed to be differentiated from metastatic tcc from other sites and undifferentiated carcinomas of ovaries . 
 clinical features and immunohistochemistry are helpful . 
 surgical resection is the primary therapeutic approach followed by standardized chemotherapy .