A surgeon at Stanford Hospital has filed suit against both the University and the hospital alleging racial and gender discrimination.

Denise Johnson, associate professor of surgery and the only African-American female surgeon at Stanford, filed the case on Monday in Santa Clara County Superior Court.

She claims, among other things, that she was paid less than her white and male counterparts, that she has been unfairly targeted because of past complaints she made against the University and that she was asked to submit to a random drug test even though the practice is inconsistent with hospital policy.

“We believe Dr. Johnson’s case is without merit,” wrote Paul B. Costello, a spokesperson for the Stanford Medical Center, in a brief statement.

He also denied that Johnson had been required to submit to drug testing.

In addition to compensation for lost wages and emotional distress, Johnson is seeking to prohibit random drug testing on the grounds that it is a violation of privacy.

She also claims that she was not asked to apply for the position of chief of breast surgery even though she specializes in cancer research and is well-known in the field. But Costello denied any “pattern of employment discrimination” against Johnson.

“During the past few years,” Costello wrote, “Dr. Johnson has been promoted in two instances: first, to an assistant dean for medical student advising in September 2002 and second, from assistant to associate professor in the medical school in May 2003.”

After she was passed over for the chief of breast surgery position, Johnson said the hospital reduced the number of patients she would receive, causing her practice to lose 77 percent of its business.

In March 2005, Johnson sent an e-mail to the Medical School Dean’s Office estimating that she had been paid $500,000 less than “similarly situated surgeons” since 2000. Less than a week later, she was accused of being under the influence during surgery. Johnson contends that this incident led directly to the drug testing, the results of which were negative.

These allegations come as Stanford, like many of its peer institutions, struggles to increase minority and female representation.

The University Provost’s Advisory Committee on the Status of Women Faculty, for example, reported that women in the clinical sciences are “are significantly less likely than their male colleagues to perceive their workplace as supportive” or “to believe that they receive sufficient information for professional advancement.”

Campus-wide, the number of black faculty dropped by 2.2 percent last year, and the number of female faculty grew by only 0.4 percent, according to a report presented to the Faculty Senate on April 28.

Johnson has received numerous scientific grants for breast cancer research and several teaching and mentoring awards from the University.

In 1989, she became the first African-American woman hired in the General Surgery Department. Before that, she worked at the Stanford-affiliated Palo Alto Veterans Administration Medical Center until she was fired in 1997 for refusing to take part in firing or demoting two other physicians.

During her employment at Stanford, Johnson and several other female physicians and faculty members submitted a complaint against Stanford with the U.S. Department of Labor.

Her most recent lawsuit claims that when Stanford learned about that complaint, Johnson and the other women were “systematically targeted” for harassment and discrimination.

In a 2000 article about racism that appeared in the weekly newspaper Metro, Johnson spoke about her experience as a minority physician.

“At Stanford, sometimes patients used to think I was a nurse or a medical student or something,” she said. “Now that I’m older, they think that I’m a resident. But you can’t be a full-fledged doctor.”

Johnson’s attorney, Kathleen Lucas of the San Francisco-based Lucas Law Firm, told The San Jose Mercury News that her client hopes to continue her work and research at Stanford.