A reappraisal of "basaloid carcinoma" of the cervix, and the differential diagnosis of basaloid cervical neoplasms.

"Basaloid carcinoma" of the uterine cervix is a neglected and underrecognized entity that is not included in the current World Health Organization's classification of cervical neoplasms. Historically, this term has been used synonymously with adenoid basal carcinoma (ABC). In recent years, however, it has become evident that a broad spectrum of basaloid cervical neoplasms exist. At one end of the spectrum are low-grade lesions, such as ABC; at the opposite end of the spectrum there are aggressive tumors, including adenoid cystic carcinoma, large cell neuroendocrine carcinoma, and basaloid squamous carcinoma. The purpose of this review is to revisit the concept of basaloid tumors of the cervix, to define their morphologic spectrum, and to address potential pitfalls in the differential diagnosis. To avoid confusion, use of the term "basaloid squamous cell carcinoma" is recommended when diagnosing a cervical tumor with histologic features of "basaloid carcinoma," as seen in other anatomic sites. A proposed classification of basaloid tumors of the uterine cervix is also presented.