Spindle cell carcinoma of the breast: four cases and review of the literature.

The clinical and morphologic features of four cases of spindle cell carcinoma of the breast are presented, and the comparable features of 35 previously reported cases are reviewed. All tumors contained histologically malignant squamous carcinoma that tended to blend with a spindle cell "pseudosarcomatous" stroma. Patients with this rare tumor tend to present at the same age as patients with other histologic types of breast carcinoma, but the spindle cell tumors are somewhat larger. Although the number of reported patients is too small to serve as a basis for firm conclusions, the prognosis appears similar to that for patients with conventional infiltrating duct carcinoma of the breast.