NEW YORK (Reuters Health) - One in every hundred breast cancers or so occurs in men, and such tumors are often detected at a late stage. Furthermore, these cancers can appear benign on mammography, according to a report in the American Journal of Roentgenology.

Breast tumors in men are usually palpable by the time they're discovered or they show signs "such as change in overlying skin or nipple," Dr. Wei-Tse Yang told Reuters Health.

"Be attentive to any palpable masses in men and obtain imaging evaluation early," he advises doctors.

In their report, Yang from The University of Texas M. D. Anderson Cancer Center, Houston, and colleagues describe the appearance of male breast tumors as seen on a mammogram or by ultrasound.

Among 244 men with breast cancer, only 57 underwent preoperative mammography or sonography, and that was because of clear signs of a problem: 54 had a palpable mass and two had nipple inversion or nipple discharge.

In a third of the cases, mammography showed a calcified mass, which is often considered to be benign.

"Radiologists should be aware of these findings to avoid the misdiagnosis of cancer in men as a benign lesion," the investigators say.