Tubulolobular invasive breast cancer: a variant of lobular invasive cancer.

Attention is directed to an apparently unique form of invasive breast cancer designated as tubulolobular invasive cancer. These neoplasms exhibit small tubules as well as cords of neoplastic cells in a lobular configuration reminiscent of lobular invasive carcinoma. The clinical and pathologic characteristics encountered in 24 examples were statistically compared with those of infiltrating ductal carcinomas without special specific features, pure tubular, and pure lobular invasive cancer. The results of these analyses as well as the morphologic characteristics of these lesions prompt the conclusion that this lesion represents a tubular variant of lobular invasive carcinoma. Short term treatment failure rates in patients with tubulolobular invasive carcinoma are intermediate between those of pure tubular cancer and lobular invasive carcinoma.