Spotlight on Pathology: A Key Component of Cancer Care

Pathology assistant Annabel Canhao analyses tissue from a biopsy.

Ten teams of experienced, disease-specific pathologists at Memorial Sloan Kettering analyze more than 60,000 tissue samples each year.

Is it cancer? Is it aggressive? Will my disease respond to chemotherapy, hormone therapy, or radiation? Am I a candidate for a targeted therapy? Pathologists are doctors who are specially trained to sleuth out the answers to these and other questions. An accurate pathology report is crucial to getting a precise diagnosis and deciding on the best treatment plan for you.

Patients at Memorial Sloan Kettering benefit from the experience and expertise of our ten teams of disease-specific pathologists, who use state-of-the-art equipment and the most advanced techniques to analyze more than 60,000 tissue samples each year. Some samples are received as a biopsy, which involves the use of a needle to extract tissue from a suspicious mass. Others are actual tumors removed during surgery.

We asked pathologist Meera Hameed to explain why results can change after the first diagnosis, and to give us some more insights into the crucial importance of precise pathology.

A Small Piece of the Puzzle

The most effective cancer treatment starts with an accurate diagnosis. However, a pathologist may come up with different findings after analyzing tissue taken from a biopsy versus analyzing a tumor sample. “It’s unusual for there to be such differences in pathology results, but sometimes it depends on the type of tumor being biopsied or where in the body the biopsy is taken from,” says Dr. Hameed, who is Acting Chief of the Surgical Pathology Service. “Some growths are tumors but may not be cancerous. Others are located in a part of the body that is not easy to access with a biopsy needle, so the pathologist may not receive enough material to run the necessary tests to make a conclusive diagnosis.”

“For example,” she continues, “an interventional radiologist performing a biopsy procedure might only be able to extract a few millimeters of tissue from a tumor that measures five centimeters or more, so you may be getting just a small piece of the puzzle.”

In some instances, the appearance of cancer cells can vary even within a tumor. A biopsy sample may show one thing, “but when you examine a larger tumor sample after surgery there may be more than one possible diagnosis requiring additional studies or, rarely, even a change in diagnosis,” Dr. Hameed explains.

This morphologic and molecular diversity seen in some tumors — known as intra-tumor heterogeneity — can have important consequences for how cancers are diagnosed and treated.

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Looking at the Bigger Picture

Pathologists use a microscope to scrutinize the appearance of cells and run additional tests to ascertain the nature of the cancer and understand how it behaves and whether it’s likely to spread. They are also improving diagnostic accuracy with the use of newer technologies such as genetic sequencing, which can further classify cancers and reveal genetic mutations or alterations in tumors that drive growth and can help guide therapy.

“It’s like putting together pieces of a puzzle in order to clearly see the bigger picture,” says Dr. Hameed. “Pathological diagnosis including molecular information, taken together with what is going on with the patient from a clinical perspective — such as age, other health conditions, imaging tests, and personal and family history of cancer and other diseases — creates the full context in which personalized treatment decisions are made.”

For example, should your surgeon remove any lymph nodes in addition to your tumor? Is chemotherapy or radiation necessary to ensure that no stray cancer cells have been left behind after the operation? Do certain mutations found in your DNA suggest that your cancer will be responsive to a targeted therapy? Or, if your cancer appears to be slow-growing and not aggressive, can you defer treatment and opt for an approach called active surveillance, in which you’d be closely monitored for changes in your disease through imaging and other screening tests? The answers to all these questions begin with a complete and accurate pathology report.

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The Best Care Begins with the Right Diagnosis

Communication between my group and the treatment team taking care of the patient is an absolute must.
Meera Hameed Pathologist

Like our clinicians, pathologists at Memorial Sloan Kettering are all sub-specialized and bring extensive experience to their respective fields. “Communication between my group and the treatment team taking care of the patient is an absolute must,” says Dr. Hameed, who notes that she and other pathologists participate in weekly meetings with the clinical team to review complex patient cases.

“This is particularly useful in the diagnosis of rare cancers, such as tumors of the musculoskeletal system, which is my specialty,” she explains. “Most pathologists around the country are not able to get much exposure to rare cancers, but we see these types of diseases often enough that when patients come to MSK, they can be confident that they will receive an accurate diagnosis — and our experts can then offer them the most effective care.”

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Commenting is disabled for this blog post.

It's great to see all the care and "work" that goes into cancer treatment.

can it be one hospital diagnoses bladder cancer as low grade while sloan kettering diagnoses in high grade ? can sloan say non invasive while another hospital says penetrated lamina propria in the bladder ? thank you

Dear Harry, we do on occasion change outside diagnoses, and sometimes it is simply that we view the same slides and have a different interpretation. Sometimes there are other issues. We sent your inquiry to Dr. David Klimstra, Chair of our Department of Pathology, and he responded (with the assumption that your question refers to a difference in diagnosis of the SAME slides viewed here vs. elsewhere, rather than two different specimens, which can differ because they sampled different regions of the tumor):

“The diagnosis of pathology slides requires considerable nuanced interpretation and judgment. Although some aspects of a diagnosis may be relatively straightforward and easily recognized, there are other more subtle findings that may be viewed somewhat differently by different observers. Assigning a grade to a cancer in particular is an aspect of tumor pathology well recognized to be subjective, and the reproducibility among pathologists is not perfect. Also, in any given slide, there are many scenarios that can make the interpretation challenging, especially when dealing with small samples like biopsies, so it is not unusual for difficulties in interpretation to arise, that benefit from having the opinion of multiple experienced pathologists. In our laboratory, it is also not uncommon for additional studies to be performed that can help clarify the interpretation of challenging or controversial cases, when the issue at hand may change the diagnosis, outcome, or management of the patient.”

We hope this is helpful. Thank you for your question.

Yes, the pathologist has such an important and crucial role in a patient's treatment, yet I never knew my pathologist, didn't chose my pathologist…Remained confident that, as a patient at MSKCC, whoever my pathologist was they were working within an institution that had the highest standards in cancer treatment and care.
How does the pathology dept work in the sense of assigning a grade, given the subjectivity and judgment that is involved as the doctor above explained ? Does one other pathologist review another's work for a 'second' opinion? Or is this only when cases appear to be 'close' calls, at the discretion of the assigned pathologist? I

Dear Karen, we are unable to provide insight on how a specific diagnosis was made. If you have questions about how your pathologist reached a determination on your case, we recommend that you speak with your treating physician. Thank you for your comment.

If one goes for a second opinion at major cancer centers and the interpretation is very different, what then?

Is it possible that the MSK pathologist's team receive material from another country to analyze? If so, What Are the requirements?

Dear Eduardo, our pathologists diagnose thousands of cases annually that are sent for consultation by other pathologists, attending clinicians, and patients around the world. If you would like to send slides or samples to Memorial Sloan Kettering for consultation, please use our Pathology Consultation Request Form available on this page:

Thank you for your comment.

Too bad I didn't see until today the question which Larry Weiss asked a year ago: "can Sloan say non invasive while another hospital says penetrated lamina propria of the bladder". Your boss, Dr Klimstra gave a long-winded reply, but did not answer Larry's question. The answer is: Yes, Larry, Sloan can say "non invasive" in the case of invasion of lamina propria of the bladder. The correct term, though, is "non-muscle invasive" and we are trying to discourage use of the term "non invasive" as it is confusing and is not a good description. When the tumour has not yet invaded the muscle but only the lamina propria, we can still attempt to preserve the bladder by agents instilled into the bladder. However when the tumour invades the muscle, it is too late and the bladder needs to go".
I'm sure by now Larry must have learned the difference from other sources.

As for your reply to Karen, it was also unhelpful and dismissive. She was asking a general question about the workings of your department and not a question about a specific diagnosis. Can't you people read? Am not surprised that this forum is dead. The answer to her question is "yes, Karen, pathologists in our hospital do have their diagnostic reviewed by second pair of eyes, this is done all over the word in any good institution". If my answer is incorrect, then your patients need to be told and need to go outside MSKCC for a second opinion, no matter how good you claim to be.

We, patients, usually see and interact with physicians, surgeons, radiologists, and nurses but never with pathologists whose skill and experiences are crucial in the appropriate diagnosis of the diseases. I wish, the hospital management provides opportunity to see and interact with these scientific souls known as pathologists who silently work behind the screen in the management of our diseases.

How long does it take to get results? Will the doctor call when he gets the results of a needle biopsy back?

Dear Vicky, while a result can be ready in two days, it can take longer if we have to do additional studies. It’s best if you speak to your doctor to see what a realistic expectation would be for your particular circumstances. Thank you for reaching out to us.

I was diagnosed with papillary urothelial carcinoma, low grade in April 26, 2016. AJCC 7th edition staging pTaDr said no treatment necessary at this time. had a reoccurrence in August 2016 and again in November 2016 and had 6 weeks of BCG therapy. I'm have a cystoscope February 6 2017 and if it reoccurs I'll need another round of BCG.
I am a 70 yr old woman.
If there are new tumors and they are removed can I request my doctor send it to your pathology dept for analysis? My thoughts are, if it returns for a 4 th time I need to come, to MSK for treatment.

Dear Patricia, we’re sorry to hear you’re going through this. If you’d like to arrange for a pathology review or an appointment for a second opinion at MSK, you can call 800-525-2225 during regular business hours or go to for more information on making an appointment. Thank you for your comment, and best wishes to you.

I have had ct and pet/ct which noted lymph nodes peritoneum,nodes retroperitoneal area and peritoneal carcinamotosis.Read met Ca?I am waiting to get biopsy at Sloan nyc site.My question is I live on long island if I wanted to get the biopsy at rk center what would be my first step?I need to know if this is from ovaries or colon?I do not know which oncolgist would handle my treatment GI or Gyn?Lost and confused0

Dear Michele, we’re very sorry to hear that you’re going through this. If you call our physician referral number, our experts there can match you with the right specialist based on your situation. The number to call is 800-525-2225. You can go to for more information. Thank you for your comment, and best wishes to you.

We are scheduled for an appointment next week at MSK, do you prefer we send the slides now (taken by another Center, in California) or should we bring it with us. I am assuming that sending it earlier is preferred so our Consultation next week will take this into consideration

Dear Marie, we recommend that you call the office of the doctor you’ll be meeting with next week and ask what they prefer. Thank you for your comment, and best wishes to you on your appointment.

i was recently diagnosed with mucinous tubular and spindle cell carcinoma .To my understanding this a very rare subtype of rcc. Im concerned about my diagnosis as well as my follow up care.