Tubular carcinoma of the breast. Clinical, histological, and ultrastructural observations.

Tubular carcinoma is a neoplasm with good prognosis of features that warrant its differentiation from other mammary carcinomas and from sclerosing adenosis. Cases of nine primary unilateral neoplasms are presented and ultrastructural observations in three discussed. The mean diameter was 1.2 cm and the mean patient age was 48.7 years. None of the patients died and only one of six had residual tumor in the mastectomy specimens. Three patients had an excisional biopsy, one followed by radiation. All biopsy specimens showed infiltrating angular tubules with single-lining epithelium, minimal anaplasia, rare mitosis, and scant or absent myoepithelium. The tumor cells related to each other by desmosomes, cytoplasmic interlocking processes, and tight junctions. Myoepithelial cells were rare. Since tubular carcinomas are distinct variety of ductal epithelial neoplasms of the breast, and are well differentiated with low malignant biological behavior, a less radical approach may be the treatment of choice.