INTRODUCTION: Extensive intraductal carcinoma is proposed for tumors in which the intraductal component comprises 25% or more of the area encompassed by the infiltrating tumor.(1). Ductal carcinoma in Situ with a micro invasive component accounts for less than 1% of all breast cancers and 13.5% of all DCIS have a microinvasive component.( 2). The increased rate of early detection of breast cancer due to widespread mammographic screening has led to an increased incidence not only of in situ but also microinvasive carcinoma. DCIS with micro invasion (DCISM) results in axillary lymph node metastases, statistically significant independent predictors of lymph node metastases in DCISM are comedo DCIS. (3)

CLINICAL DETAILS: A 49 -year-old postmenopausal woman presented with mass in the right breast since three months duration, axillary lymphnodes were not palpable and the contralateral breast was normal. FNAC revealed discohesive clusters of atypical cells with prominent nucleoli in a necrotic background. The smears were termed as positive for malignancy. Patient underwent Radical mastectomy with axillary lymph node clearance.

RESULTS: On gross examination a tumor measuring 6×4×4 cm, the tumor appeared as tiny cystic spaces and grey white material extruded on pressure. Grossly all the resected margins were free of tumor and 8 lymphnodes were dissected, the largest node measured 1.5 cm in diameter. H&E sections revealed features of ductal carcinoma in situ-comedo type(gradeIII). All the margins including the deep resected margin were free of tumor. However 1/8 lymphnode showed complete replacement of the lymphnode by tumor cells. Hence with this background extensive sampling of tumor was done to rule out invasion which revealed a tiny foci of invasion<1mm and an intraductal micropapillary lesion.