clinging carcinoma , a variant of ductal carcinoma in situ ( dcis ) , is an under recognised entity . it is identified by the presence of cytologic atypia of luminal epithelial cells without simultaneous alterations of basally located myoepithelial cells . generally , intraluminal proliferation of the involved ducts or ductules is not seen . fibroadenoma is the most common benign breast tumor in adolescent girls and young women with a peak incidence in the second and third decades of life . the epithelial elements of a fibroadenoma can undergo a variety of proliferative changes similar to that seen elsewhere in the breast . this case report highlights the role of fine needle aspiration cytology ( fnac ) in the diagnosis of this entity coexisting in a fibroadenoma . a 48 years old lady , a known diabetic and hypertensive , presented with bilateral breast lumps of one week duration . , there was a 4  4 cm hard lump in lower inner quadrant of left breast which was fixed to the chest wall and there was a lump in right breast , firm mobile measuring 1  1 cm in the lower outer quadrant . impression of left breast lump on magnetic resonance imaging ( mri ) was suspicious of malignancy [ figure 1 ] . right breast lump was a 2.3  1.5 cm well defined mass lesion with type 1 contrast enhancement pattern ( less than 6% malignant probability ) with bilateral axillary lymphadenopathy . mri of bilateral breast lumps- 3.8  3.5  3 cm irregular speculated mass in left breast ( suspicious of malignancy ) , 2.3  1.5 cm well defined mass lesion in right breast ( less than 6% malignant probability ) fnac was done from both the breast lumps and left axillary lymph node . smears from the left breast showed poorly cohesive clusters of ductal cells with pleomorphism , hyperchromasia and prominent nucleoli . the smears from the right breast mass showed three dimensional clusters of cells with hyperchromatic nuclei , prominent nucleoli . admixed with these clusters were benign ductal cells with no nuclear pleomorphism along with myoepithelial cells . cytologic diagnosis of duct cell carcinoma of bilateral breast lumps with left axillary lymph node metastasis was made [ figure 2 ] . ( a ) benign ductal epithelial cell cluster ( pap , 100 ) ; ( b ) lesion with bare bipolar nuclei in the background ( mgg , 400 ) ; ( c ) and ( d ) clusters of cells with hyperchromatic nuclei and prominent nucleoli ( mgg , 400 ) trucut biopsy of left breast lump showed features of infiltrative duct cell carcinoma . immunohistochemistry was positive for estrogen and progesterone receptors . on the basis of the physical examination results , histopathology of multiple and serial sections revealed ductal structures surrounded by hyalinized stroma with focal myxoid areas . a significant number of ducts showed stratification of the lining epithelium , nuclear hyperchromasia and irregular nuclear contours , but myoepithelial lining was intact . the latter was confirmed by immunohistochemical staining with smooth muscle actin ( sma ) and pancytokeratin ( pan ck ) . a diagnosis of fibroadenoma with dcis , clinging type , ( a ) benign glands in fibroadenoma area ( h and e , 100 ) ; ( b ) dilated duct with necrotic material ( h and e , 400 ) ; ( c and d ) nuclear hyperchromasia with irregular nuclear contours ( h and e , 400 ) the term  clinging carcinoma in situ  was coined by azzopardi when a carcinoma was missed and the patient developed infiltrating ductal carcinoma 8 years later . it is characterized by atypical cells replacing the single layer of luminal epithelial cells in a flat fashion without any proliferation or micropapillary structure formation . though it was ignored for a long time , there is a renewed interest as moinfar and schnitt equated it with high grade flat epithelial atypia . in the present case , the cytologic features of the lesion were unequivocally malignant . a detailed evaluation of tubules and the lining epithelium showed foci with intraluminal necrotic debris and occasional rigid tubule . there are a few case reports with in situ / invasive ductal and lobular carcinoma in a fibroadenoma which are either cribriform / solid variants.[46 ] there are no reported cases of clinging carcinoma with fibroadenoma . the incidence of carcinoma within fibroadenoma is reported to be between 0.1% and 0.3% , with a peak age between 42 and 44 years.[57 ] the biological behavior of carcinoma occurring within fibroadenoma does not differ from that of breast carcinoma which is unrelated to fibroadenoma . preoperative clinical and radiological diagnosis of malignancy in a fibroadenoma , especially of in situ carcinoma , is usually not possible . fnac is a useful test that guides the clinician to decide further step of patient management . surprisingly , in the present case , though the clinical examination was suggestive of fibroadenoma and mri was suspicious of malignancy , fnac revealed features of duct cell carcinoma which was confirmed as clinging carcinoma on histopathology . we stress upon the need for compulsory excision of clinically diagnosed fibroadenomas and also the importance of histopathological evaluation of all breast masses irrespective of their clinical diagnosis as benign lesions . special attention is warranted in women older than 35 years and with risk factors for carcinoma breast presenting with a fibroadenoma .
fibroadenoma is the most common benign breast tumor in adolescent girls and young women with a peak incidence in the second and third decades of life . 
 carcinoma arising within a fibroadenoma is rare and is usually discovered incidentally . 
 we describe a case of clinging type of ductal carcinoma in situ ( dcis ) arising within a fibroadenoma . 
 clinging carcinoma , a variant of dcis is an under recognized entity . 
 diagnosis of dcis is made based on architecture and cytology . 
 this case report highlights the role of fine needle aspiration cytology in the diagnosis of this entity coexisting in a fibroadenoma .