mucinous carcinoma of the breast is uncommon , the reported incidence of pure mucinous carcinoma being 2% of all breast cancers .
pure mucinous carcinoma has a far better prognosis than the mixed variety noted in several studies .
we report a case diagnosed as pure mucinous carcinoma breast on fine needle aspiration cytology ( fnac ) in a female of reproductive age group .
a 30-year - old female presented with a large firm lump in upper quadrant of right breast for 4 years , which was gradually increasing in size and was associated with pain .
there were numerous moderately pleomorphic epithelial cells lying either discretely forming loose clusters or entrapped within stromal material [ figure 1 ] . at places ,
fnac smear showing abundant pink mucoid material ( arrow ) with entrapped tumor cells ( arrow head ) ( h and e , 400 ) right mastectomy specimen with axillary tail measuring 20 cm14 cm4 cm was received .
overlying skin measured 20 cm11 cm , and the axillary tail measured 9 cm6 cm2 cm .
cut surface revealed circumscribed mass with variegated appearance , grey brown in color , and solid to cystic with areas of necrosis and hemorrhage .
tumor mass measured 7 cm6 cm5 cm , and extended from subepidermal tissue to posterior resected margin .
four lymph nodes were identified in axillary tail , with the largest measuring 3 cm2 cm1 cm and the smallest measuring 1 cm0.5 cm0.5 cm . cut surface of the largest was gelatinous and necrotic .
three axillary lymph nodes with fibrofatty tissue received separately ranged from 0.5 to 1.5 cm , and had unremarkable cut surface . sections from different areas of specimen were studied .
sections from tumor mass revealed large areas of necrosis , myxoid degeneration and lakes of mucoid material [ figure 2 ] .
the tumor cells were round to polyhedral , exhibiting mild pleomorphism but frequent mitotic figures .
these cells were mostly arranged in thin trabeculae , single rows and few solid cellular areas .
tumor was reaching close to posterior resected margin but was separated by a thin rim of uninvolved fibroadipose tissue .
microscopically , seven lymph nodes were identified of which the largest was almost completely replaced by tumor metastasis .
tumor tissue was negative for estrogen receptor ( er ) and progesterone receptor ( pr ) .
section showing lakes of mucoid material ( arrow ) with enmeshed column of tumor cells ( arrow head ) ( h and e , 400 )
there were numerous moderately pleomorphic epithelial cells lying either discretely forming loose clusters or entrapped within stromal material [ figure 1 ] . at places ,
fnac smear showing abundant pink mucoid material ( arrow ) with entrapped tumor cells ( arrow head ) ( h and e , 400 ) right mastectomy specimen with axillary tail measuring 20 cm14 cm4 cm was received . overlying skin measured 20 cm11 cm , and the axillary tail measured 9 cm6 cm2 cm .
cut surface revealed circumscribed mass with variegated appearance , grey brown in color , and solid to cystic with areas of necrosis and hemorrhage .
tumor mass measured 7 cm6 cm5 cm , and extended from subepidermal tissue to posterior resected margin .
four lymph nodes were identified in axillary tail , with the largest measuring 3 cm2 cm1 cm and the smallest measuring 1 cm0.5 cm0.5 cm . cut surface
three axillary lymph nodes with fibrofatty tissue received separately ranged from 0.5 to 1.5 cm , and had unremarkable cut surface .
sections from tumor mass revealed large areas of necrosis , myxoid degeneration and lakes of mucoid material [ figure 2 ] .
the tumor cells were round to polyhedral , exhibiting mild pleomorphism but frequent mitotic figures .
these cells were mostly arranged in thin trabeculae , single rows and few solid cellular areas .
tumor was reaching close to posterior resected margin but was separated by a thin rim of uninvolved fibroadipose tissue .
microscopically , seven lymph nodes were identified of which the largest was almost completely replaced by tumor metastasis .
tumor tissue was negative for estrogen receptor ( er ) and progesterone receptor ( pr ) .
section showing lakes of mucoid material ( arrow ) with enmeshed column of tumor cells ( arrow head ) ( h and e , 400 )
mucinous carcinoma of the breast is an uncommon entity seen in postmenopausal females , accounting for only 2% of all breast carcinomas .
however , we are reporting a case of mucinous carcinoma in a young female aged 30 years .
the behavior of the tumor tends to be less aggressive , so it has a better prognosis than other breast malignancies .
as soon as another pattern becomes evident as a component of tumor mass , the lesion qualifies as a mixed tumor .
two lesions most likely to be confused with mucinous carcinoma are mucoid fibroadenoma and mucocele like lesion .
mucinous carcinoma is er positive , and in less than 70% cases , it is pr positive .
nearly all pure mucinous carcinomas are diploid , while over 50% of mixed variety is aneuploid .
only 315% of pure variety shows axillary node metastasis compared to 3346% of the mixed type . in the present case ,
the present case did not show any distant metastasis either at the time of diagnosis or during the 1 year of follow - up .
adjuvant chemotherapy containing cyclophosphamide , adriamycin and 5 fluorouracil ( 5 fu ) was given at every 3 weeks interval .
histochemically , the mucins secreted by this tumor are distinct o - acylated forms of sialomucin .
immunohistochemically , there is strong muc ( mucin ) 2 cytoplasmic immunoreactivity and decreased muc i immunoreactivity compared with ductal carcinoma not otherwise specified ( nos ) .
we have reported a case of pure mucinous carcinoma in a young female emphasizing the role of fnac in its early diagnosis .
 mucinous carcinoma of the breast is a relatively rare , pure form accounting for 2% of all breast cancers 
 . pure mucinous carcinoma of the breast has a favorable prognosis . 
 the common age is postmenopausal group . here 
 , we report a 30-year - old female patient diagnosed on cytology as mucinous carcinoma of the breast with lymph node metastasis and subsequently confirmed by histopathology . in 1 year follow - up , 
 the patient did not show pulmonary or distant metastasis and received adjuvant chemotherapy at every 3 weeks interval . 
Introduction
Case Report
Pathological findings
Discussion
Conclusion