Tubulopapillary Carcinoma: An Aggressive Variant of Invasive Breast Carcinoma With a Micropapillary DCIS-Like Morphology

Tubulopapillary carcinoma is a recently described variant of breast carcinoma characterized by a proliferation of elongated and anastomosing tubular glands exhibiting intraluminal micropapillary and sometimes papillary epithelial projections. We have recently encountered a patient with invasive breast carcinoma displaying a prominent tubulopapillary component. The histomorphology in our case had an uncanny resemblance to micropapillary ductal carcinoma in situ, but the invasive nature of the glands was confirmed not only by the lack of myoepithelial cells but also by the presence of identical metastatic foci within ipsilateral axillary lymph nodes. This case was made all the more intricate by the simultaneous presence of invasive micropapillary carcinoma in the opposite breast and a carcinosarcoma of the uterus with a serous papillary carcinoma component. As noted in the only prior report on tubulopapillary carcinoma of the breast, our case confirms the aggressive nature of this form of invasive carcinoma, the histological features of which appear to be easily identifiable and reproducible.