A growth removed Monday from an area above Nancy Reagan's upper lip was malignant, Sheila Tate, the first lady's press secretary, said yesterday.

"It was adequately excised and should require no further treatment," said Tate in a prepared statement.

She described Mrs. Reagan as "startled" by the biopsy results and said the president's reaction was "a mixture of concern and relief."

The first lady heard the news that the growth was a malignancy, called basal cell epithelioma, yesterday morning from White House physician Dr. Daniel Ruge. It was in his White House office that Dr. Diane Colgan of Bethesda, a plastic surgeon, performed the minor surgical procedure Monday.

According to Tate, Mrs. Reagan called the president to tell him of the biopsy results, but he was in a meeting with Jordan's King Hussein. Later he called her back, then joined her in the family's upstairs living quarters.

Tate said Mrs. Reagan first noticed the abnormality about two months ago but kept thinking it would go away. When it became "bothersome" -- it started to bleed -- she brought it to Dr. Ruge's attention. He scheduled the surgery for Monday.

Dr. Douglas Robins, a Washington dermatologist, said yesterday that basal cell epithelioma, also known as basal cell carcinoma, is the most common type of skin cancer and that it rarely metastasizes, or spreads to other parts of the body. He said the cancer almost always results from sun exposure that is not necessarily recent but cumulative over a lifetime.

Tate said Mrs. Reagan told her that as a child she used to spend a lot of time in the sun at summer camp.

"She said she used to get very tan," said Tate.

Earlier in the day, the first lady quipped to her staff that she had "a stiff upper lip." Later, after hearing the biopsy report, she also quipped that she would be at the senior White House staff party she and the president were giving last night "with bandages on."

The four stitches closing the wound are scheduled to be removed Sunday, according to Tate.

On Monday, Tate quoted doctors as describing the thickening of the skin above Mrs. Reagan's upper lip as keratosis. Actinic keratoses, common in older people, are considered precancerous and easily treated.