What’s your reference question?
I received this question from one of our oncologists:
“We are coming out with a new book, The Mayo Clinic Breast Cancer Book. There is one mystery for which I need expert detective help. In our original book on women’s cancers [Mayo Clinic Guide To Women’s Cancers], we had a figure on p 41 showing a metastatic cell entering a lymph node. This originally was published in the NEJM as “an image” – I can’t remember the name of the series that they used to run but they would show specific pictures. We want to include this figure in the new book, but I need a better citation than simply NEJM and I don’t have the original. Is there any way that you might be able to find this for us?”
My first step was to look at the figure on page 41. I found a copy of the book at our Cancer Education Center. The legend for that particular figure read “Metastatic breast cancer occurs when breast cancer cells spread to other parts of the body. The cells use lymphatic vessels and blood vessels as a means of travel to other areas. This microscopic image shows cancer cells (see arrow) entering a lymph node through a lymphatic channel. Reprinted with permission from the New England Journal of Medicine.”
My second step was to log into Medline. This is what I knew for sure: the article would have been published before 2005 since that was the copyright date of the book, and that it was published in the New England Journal of Medicine (NEJM). I figured that it was part of the NEJM Images in Clinical Medicine series. My initial search in Medline was “New England Journal of Medicine.jn” + “Images Clinical Medicine.ti” (jn refers to “journal name” and ti refers to “title”– as in words in the title of the article). I limited the search between 1960-2005, which resulted in 795 hits. To narrow the search, I started adding keywords based on the text supplied in the legend. I figured that the image may not have anything to do with breast cancer, so I tried variations of lymphatic vessels or blood vessels or lymph nodes or lymphatic channel. None of those resulted in the image I was looking for. This now meant doing what we librarians call “hand searching” — or more appropriately “scroll searching”– as I would have to scroll through 795 references to find that nugget.
I could have scrolled through the titles of the 795 Medline citations, but I chose to go to the NEJM’s web site where I could also limit to “Images in Clinic Medicine” between 1960-2005. The advantage to this option was that the images were displayed next to the references, and I knew what image I was looking for. With a little perseverance, I found the image: A Metastasis Caught in the Act in volume 335, page 1733, December 5, 1996!
Why didn’t I find it in Medline? It’s there — I found it when I had all the information from NEJM: Brat DJ, Hruban RH. Images in clinical medicine. A metastasis caught in the act. N Engl J Med. 1996 Dec 5;335(23):1733. PubMed PMID: 8929265. The one keyword I didn’t use was metastasis (or a truncation of metastasis), which was a big oversight on my part since it was one of the keywords in the figure’s legend. Why didn’t any of my keywords find the reference even though they are in the text of the article? There are no abstracts associated with the articles in the Images in Clinical Medicine series. So, unless my keywords were in the article title or the subject headings, I wouldn’t find the reference. Although I wasn’t thorough with my search strategy, it led me to play with the NEJM web site and discover the bonus of having the images display alongside the reference.
Entry filed under: What's Your Reference Question?.