Papillary carcinoma of the breast consists of 3 morphologically distinct established subtypes: encapsulated papillary carcinoma, solid papillary carcinoma, and invasive papillary carcinoma. Papillary carcinoma is one of the special types of breast cancer and, as such, carries a more favorable prognosis. We sought to identify primary breast tumors with tubulopapillary morphology and correlate this finding with predictors of adverse prognosis. We investigated our pathology files for breast tumors exhibiting tubulopapillary features. The dominant morphology consisted of infiltrating gaping tubules with intratubular papillary projections. The study group consisted of 12 cases of papillary carcinoma with tubulopapillary features. A control group of 17 cases of papillary carcinoma were selected consisting of 4 encapsulated papillary carcinomas, 3 solid papillary carcinomas, and 10 invasive papillary carcinomas. The study group showed significantly higher mitotic rate, ki67 proliferation index, nuclear grade 3, lymphovascular invasion, p53 overexpression, unfavorable biomarker signature, and axillary nodal involvement compared to the control group (P = .01, .01, .04, .01, .007, .0001, .03, respectively). Invasive breast carcinomas with tubulopapillary features demonstrate significant correlation with predictors of adverse prognosis compared to ordinary papillary carcinomas. Larger studies with survival analysis are required to confirm aggressiveness in this group of breast cancers.
Keywords: behavior; breast; carcinoma; papillary; tubulopapillary.