Underdiagnosis of breast malignancy: Azzopardi's Problems in Breast Pathology revisited, part II.

In the second part of this two-part review series, we revisit Chapter X of the seminal textbook Problems in Breast Pathology written by Dr. John G. Azzopardi and discuss breast malignancies which may be underdiagnosed. We include the two major lesions covered in Dr. Azzopardi's textbook: ductal carcinoma in situ and lobular carcinoma in situ. Furthermore, we discuss microinvasive carcinoma, residual invasive carcinoma status-post neoadjuvant treatment and carcinomas with certain morphologic features which may lead to underdiagnosis. While discussing these lesions, we highlight problems raised by Dr. Azzopardi and discuss both their morphologic features as well as ancillary tools developed since then to aid reaching the diagnosis.