adrenocortical carcinoma ( acc ) is a rare malignant tumor with an incidence of one to two cases per million per year . imaging studies can easily and precisely visualize intra - abdominal mass lesions and computed tomography ( ct)-guided fine needle aspiration cytology ( fnac ) may be used for early confirmation and exclusion of neoplastic diseases in cases presenting with intra - abdominal masses . the morphologic distinction of acc from renal cell carcinoma ( rcc ) in fna material is not always feasible based on cytology alone . to date , the immunohistochemical distinction of acc from rcc is based on a panel of antibodies that include vimentin , cytokeratins and epithelial membrane antigen ( ema ) . a 48-year - old lady presented with flank pain and abdominal mass for the last 6 months . ct of the abdomen showed a large mass arising from the upper part of the left kidney . cytologic smears showed pleomorphic large cells arranged discretely and in small aggregates against a myxoid background . in some nuclei , conspicuous nucleoli were present [ figure 1a ] . based on cytomorphology , differential diagnoses of acc and rcc were made . ( a ) cytologic smears showed pleomorphic large cells arranged discretely and in small aggregates against a myxoid background . the cells have a high nucleocytoplasmic ratio , anisonucleosis and conspicuous nucleoli ( mgg , 400 ) . ( c ) gross appearance of the adrenocortical carcinoma : the cut - section showed that the tumor had a variegated appearance with myxoid areas . ( d ) histology showing an encapsulated tumor with myxoid areas ( h and e , 100 ) immunocytochemistry was performed with a panel of antibodies . the tumor cells were found to be positive for synaptophysin , inhibin , vimentin and melan - a [ figure 1b ] . a cytodiagnosis of myxoid acc was made based on clinicoradiological , morphologic and immunocytochemical results . subsequently , the patient underwent resection of the tumor and histopathologic examination was carried out . gross examination revealed that the tumor had a diameter of 7.5 cm and that it weighed 543 g. the cut - section showed that the tumor had a variegated appearance with myxoid areas [ figure 1c ] . microscopic examination showed a capsulated tumor composed of large cells with a high nucleocytoplasmic ratio , pleomorphic nuclei and prominent nucleoli . immunohistochemical analysis was performed with the same panel of markers used for immunocytochemistry and similar results were obtained . after correlation with all the above features , a final diagnosis of myxoid acc was established . the adrenal gland has become a frequent target of fnac with the availability of sensitive imaging techniques and better localization . currently , fnac is the only non - surgical means of obtaining a diagnosis in a patient with adrenal mass . the fna specimens from adrenal tumors are usually cellular and show tumor cells in a lipid - rich background ( best seen in diff - quik - stained slides ) . the individual cells display central or eccentrically placed nuclei with evenly dispersed chromatin and small nucleoli . the cytoplasm is usually foamy and ill defined , and a majority of cells can appear as stripped nuclei . the cells can occur as large cohesive fragments or singly scattered cells ; some specimens can show mostly singly scattered cells , which can occur as a function of smearing technique or in large adrenal tumors with necrosis . it is a challenge in cytology practice to differentiate between aspirates from rcc and adrenocortical tumors . specimens from rcc usually lack a lipid - rich background ; however , it is important to obtain enough material for immunostains to differentiate between these two entities . in our case , the cytologic smears showed pleomorphic large cells arranged discretely and in small aggregates against a myxoid background . the cells had a high nucleocytoplasmic ratio along with anisonucleosis and conspicuous nucleoli . based on these findings , immunohistochemically , strong positivity for cytokeratin , ema , cd10 and lewis blood group isoantigen favors rcc , whereas positivity for inhibin , a103 , melan - a and synaptophysin favors acc . on histologic samples , it is generally found that acc displays immunoreactivity for vimentin but not for ema , whereas rcc is often immunoreactive with ema but negative for vimentin . alfa - inhibin antibody shows an intense and specific immunostaining pattern for cells of adrenal origin , even in paucicellular samples , and there is a scope for widespread clinical utility of this marker by cytopathologists . the tumor cells , in our case , were found to be positive for synaptophysin , inhibin , vimentin and melan - a . jain et al . found in their study that no adenoma was larger than 5 cm and that no carcinoma was smaller than 6 cm gross examination in our case revealed that the tumor had a diameter of 7.5 cm and that it weighed 543 g. the cut - section showed that the tumor had a variegated appearance with myxoid areas . the weiss system , first introduced in 1984 , provides specific guidelines for differentiating adrenocortical adenoma from acc , and is considered the standard for determining malignancy in tumors of the adrenal cortex . the nine histological parameters evaluated in this system are high nuclear grade ( nuclear grade iii and iv based on the criteria of fuhrman et al . ) , mitotic rate > 5/50 high - power fields ( hpf ) , atypical mitotic figures , clear tumor cell cytoplasm ( less than 25% tumor cells ) , diffuse architecture ( greater than 33% of tumor ) , necrosis , venous invasion , sinusoidal invasion and capsular invasion . a tumor is labeled malignant when it meets four or more of these histological criteria . microscopic examination in our case showed a capsulated tumor composed of large cells with a high nucleocytoplasmic ratio , pleomorphic nuclei and prominent nucleoli . acc was made , in accordance with the weiss criteria and the results of the relevant investigations that had been performed previously . stated in their study that a combined evaluation of clinical features , size or weight , microscopic appearance , immunohistochemical and molecular genetic data is necessary to ensure a correct diagnosis of adrenal masses . to conclude , fnac is a quick and reliable diagnostic method for acc and immunocytochemistry plays a pivotal role in resolving diagnostic dilemma , especially to differentiate it from rcc .
adrenocortical carcinoma ( acc ) is a rare malignancy and cytodiagnosis of this tumor is not routinely encountered by a cytopathologist . here 
 , we report a case of acc initially diagnosed by computed tomography ( ct)-guided fine needle aspiration cytology ( fnac ) with the help of immunocytochemistry . a 48-year - old lady presented with flank pain and abdominal mass for the last 6 months . 
 a ct scan of her abdomen revealed a large mass arising from the upper part of the left kidney . 
 ct - guided fnac was performed . 
 cytologic smears showed pleomorphic large cells arranged discretely and in small aggregates against a myxoid background . 
 the cells had a high nucleocytoplasmic ratio , anisonucleosis and conspicuous nucleoli . based on cytomorphology , differential diagnoses of acc and renal cell carcinoma ( rcc ) were made . 
 on immunocytochemistry , the tumor cells were synaptophysin , inhibin , vimentin and melan - a positive but cytokeratin and epithelial membrane antigen negative . 
 thus , a cytodiagnosis of myxoid acc was made and histopathologic examination was suggested . 
 subsequent histologic examination and immunohistochemistry proved the case to be myxoid acc .