An "extremely rare" handwritten poem by Anne Frank, penned shortly before she went into hiding from the Nazis, is to be auctioned and could fetch up to 50,000 euros ($55,000), the auctioneers said Thursday.

The poem was written in the friendship book of the older sister of Anne's best friend, and is signed by the Jewish teenager and dated March 28, 1942, auctioneers Bubb Kuyper said.

The 12-line long text, written with black ink on white paper, is reportedly only the fourth time that something in the young diarist's handwriting has gone up for sale, according to the Dutch daily NRC.next.

"The Diary of a Young Girl," which Frank wrote while hiding from the Nazis in an Amsterdam attic from June 1942 to August 1944, has sold more than 30 million copies and been translated into 67 languages.

She died in the Bergen-Belsen concentration camp in Germany in early 1945 less than a year after the Nazis found her and her family members.

"Autographs by Anne Frank are excessively rare and have come onto the market only sporadically in the past 35 years," the auctioneers said in a statement, estimating it could sell for between 30,000 to 50,000 euros.

A series of letters between Anne and her sister Margot with American penpals were sold for $165,000 in 1988. And a 1925 edition of Grimm's fairy tales, with both girls' names written on the title page, went for $62,500 in May in a New York auction -- fetching twice the estimated price.

The poem, which had been written into the book belonging to "Cricri" van Maarsen, the oldest sister of Frank's friend Jacqueline, is "a typically edifying poem of the sort that was often written" into friendship books, the auctioneers said.

The first four lines were probably copied from a 1938 periodical, but the following four lines have so far not been traced to another source.

Frank was to die of typhoid in the concentration camp at the age of 15, just months before World War II ended. The house in which she and her family hid has long been a museum.

While it is not planning to bid for the poem at the auction on November 23, the museum said "it is extraordinary to find an unknown manuscript after so many years," NRC added.