Several more reports of spinal tumors from nasal stem cell transplants

Woodworth, et al. Figure 1 spinal tumor imaging after nasal stem cell transplant. CMAJ 2019.
Woodworth, et al. Figure 1 spinal tumor imaging after nasal stem cell transplant. CMAJ 2019.

At least four cases of spinal tumors have now been reported following experimental nasal stem cell transplants for paralysis.

There’s some risk of tumor development with just about any stem cell transplant, but risks are higher with experimental injections of unproven stem cells. Whill risks of tumor formation come along even with standard bone marrow and whole organ transplants (both extremely low), there’s a lot more data in those contexts to understand these tiny risks. With unproven stem cell transplants things are often much murkier and riskier. Update: note that the nasal tissue/cell transplant in some of these cases may or may not have contained stem cells. It’s unclear.

Woodworth, et al. Figure 1 spinal tumor imaging after nasal stem cell transplant. CMAJ 2019.
Woodworth, et al. Figure 1 spinal tumor imaging after nasal stem cell transplant. CMAJ 2019.

In the relatively newly reported cases of olfactory stem cell-related tumors, things are only now coming into focus. A worry is that the tumors often develop many years after injections making them hard to track. I’ve written before about how nasal transplants can lead to tumors such as this past case.

A new case report describes a spinal tumor in a 38-year-old patient with paralysis. The paper entitled “Intramedullary cervical spinal mass after stem cell transplantation using an olfactory mucosal cell autograft” is from authors Claire F. WoodworthGregory JenkinsJane Barron and Nanette Hache. In this case a patient developed a nasal-like tumor a dozen years after getting an olfactory mucosal stem cell transplant. You can see in a screenshot from Figure 1 above that there’s an odd area (the tumor) right in the middle of the spinal cord (more clearly apparent in panels A and C). Look for the two parallel bright “lines” vertically which are interrupted roughly in the middle (on the vertical axis) by the heterogeneous mass in A.

Woodworth, et al. do a nice job of putting this tumor in context of previous reports of similar tumors in other patients who also have nasal stem cell transplants. It’s unclear if these transplants have much upside for potential benefit so the tumor risk in my view makes it inadvisable to continue this type of research without some serious contemplation of how to make it safer first. The paper leaves things unclear as to the patient’s prognosis. It concludes:

“Given the vulnerability of patients who are chronically ill, especially those with spinal cord injury or neurologic disorders who may be targets of Internet-based marketing for stem cell therapy), physicians in Canada should be aware of the rationale behind stem cell therapy as well as the reported adverse events. Both family physicians and specialists may need to counsel patients on stem cell transplantation or diagnose complications in those who have had these procedures.”

Overall, this report also highlights how transplants of adult stem cells are not by definition safe or free from risk of tumors, contrary to some myths out there.


  1. After reading the paper I could not find any description for the “stem cell” part of the procedure beyond the mucosal autograft. Since that was the point of the paper, it would be important regardless of any causal opinion. Did the other 140 cases have similar complications. Do they have any documentation I might review?

  2. My apologies. The original publications indicate the procedure was free of charge. In fact there were no stem cell transfers, although they did assay mucosa from 6 of 20 patients to document “stem cells “ but not to implant. They indicate there is 100,000,000 per cc which seem incredible, and I don’t believe that is likely. I believe that his point was that the mechanism of success is partly due to the native stem population in the mucosa. The article you presented would not fair well in any medical journal club.

  3. The original article is completely different than what is ‘alluded to’ both in this Niche article as well as the CMAJ article from which the 2nd hand information what obtained. They did not take ‘Stem Cells’ but “A submucoperiosteal tunnel was created in the most posterior–superior region of the medial (septal) side of the olfactory groove, and sufficient tissue was collected to fill the spinal cord cavity and to allow for histological and microbiological examination.”

    (2) (PDF) Olfactory Mucosa Autografts in Human Spinal Cord Injury: A Pilot Clinical Study. Available from: [accessed Jul 09 2019].

    Both articles seem to be stating, at least to my eye, that the tumors occurred due to ‘nasal stem cell treatments’. First, I believe the Nasal mucosal spraying of stem cells is bogus. But these 2 articles lead me to believe that it was this ‘nasal spraying of STEM CELLS’ which is what caused the tumor, and it couldn’t be further from the truth.

    The surgeons transplanted actual nasal tissue into the cervical cord. Enough ‘to fill the cavity’. That tissue has one of 2 options, to die and be removed, or to have adequate nutrition and environment to continue doing what it does… and that is to be nasal mucosa… albeit in an ‘incorrect’ location.

    To be clear, Nasal administered Stem Cell treatment is bogus. But this is NOT what occurred in this tumor case. Not in the least.

      • I believe that is simply the rationale for their thinking. If you believe this surgery to be a Stem Cell treatment, then every transplantation of tissue be it fat allograft for breast augmentation to bone graft for fracture healing or fusion would be stem cell treatments. This was a simple swing-and-a-miss study which took tissue from one location and it grew in another. The methods in the study clearly states what the surgeon did.

    • @David,
      Wow, you sound like Donald Trump with your whole “witch hunt” thing.
      You also seem behind the times. CIRM funds many diverse clinical trials, quite a few of which are focused on adult stem cells.
      Stem cell research will go on even if CIRM is not renewed in coming years, although funding across the board is always a challenge.
      I don’t see failure of my “whole segment” (whatever that means) happening. What’s your interest in stem cells?

      • Paul –

        Please don’t try and cover the true mission with this blog –

        After 2+ decades, your stem cell segment (ESC, iPs) has yielded NO legitimate human translation of any kind – and wasted billions of public and private money

        Ocata / Astellas and BioTime, as prime examples, have sat there stuck in Phase 1b limbo for years –

        The ASC segment indeed has some bad actors, but much quality work is going on there as well –

        But you want to lump it all together in your “dangerous and unproven” basket to serve only one end – to detract from the failure on your side of things –

        A pure scorched earth strategy –

        And look! right away, you’re doing it in your next post too –

        A major medical fraud and tax evasion case – and…because they ALSO had some stem cell junk in their basket of crime, it becomes a stem cell story for you –

        Your blog used to have good science stories and make me think –

        Now it is a pure waste basket for your indiscriminate mud slinging at a broad range of people – shame on you

        • You seem to lack an understanding of the progress made in the ES/IPS field. The fact you have even referred to IPS means you’ve seen the progress first hand- tell me again when these cells were first created and justify your comments around wasted time and money? You seem to expect a magical therapy to materialize….from what? You do understand that basic research precedes clinical trials and magical cures, and that this research takes decades and a lot of money? To me, developing methods to reprogram adult cells to an embryonic state is huge progress. In time, this may lead to cell therapies for a variety of conditions but there is an enormous amount of due diligence and understanding needed even for preliminary safety trials. Which brings us back to the theme of this post, which is that people that circumvent the basic science and put cells into people with no real justification or understanding are doing nobody any favours, whether the cells are ASC or embryonic in nature.

          If you want to come and denigrate the blog that’s your decision but why are you even here if it’s such a waste of your precious time? Your argument is fallacious and shows you just want the cure without the process that needs to be put in place to enable it.

        • @David,
          Unfortunately, there’s a lot of bad news around stem cell clinics lately and it’s important for patients to learn the realities to make better informed decisions. Someone also has to stand up for responsible clinical research. I’m all in favor of responsible clinical research on adult stem cells, but I’ll never support for-profit injections of people with unproven stem cells and I’ll keep calling it out when I see it, especially if it is especially risky in my view or economically harmful to patients and their families. Paul

  4. David, respectfully, investment in basic research is not a “scam”, nor is it meaningless if if does not produce therapeutics within a short time frame. You need to be aware, if you are not already, that pharmaceutical drug products, which generally have far simpler modes of action than do any type of stem cell, can easily take 10-20 years before there are safe, efficacious products released to the public. It is unfortunate that it takes so long, but there are many “boxes which need to be checked” before scientific industry can be fully confident in something that is marketed as a treatment option. As someone who’s worked in pharma and biotech, I can tell you we all want GOOD, SAFE products out there….at least all of the people I’ve known over 30+ years, and that numbers in the many of thousands.

    While I don’t agree with Paul on every point he makes, I understand his concerns that so many are so willing to completely bypass the sort of scientifically rigorous preclinical and clinical trial work that pharma has to undergo. Do you think the elderly women who were blinded by stromal vascular fraction injections into their eyes could have been prevented if appropriate “homework” had been done beforehand? Knowing Paul’s point-of-view and understanding that at least SOME people will feel the way he does, I factor that into my decisions. I abandoned ES many years ago because I saw it was creating a lot of ethical and moral dilemmas for people. I am respectful of Paul’s opinions just as I am yours….you BOTH have the right to feel the ways you do.

    Simply put, loosening the regulatory safety net increases the risks to sick people….plain and simple. That would concern me, too. It may also bring false hope to people and cause them to forego proven treatments in favor of unproven ones. In the case of iPS and ES cells, which represent a HUGE leap forward in our understanding of cell biology, it is not unreasonable to expect a long development time….after all, Watson and Crick did their DNA work in the 1950’s, and it is only in recent times that we have seen attempts at gene-based therapeutics. How much money do you think it has taken to get to the point of CRISPR, David? There is nothing wrong with proceeding with caution when one does not understand an approach or a process completely, and I’d rather see that than CRISPR babies or rushes to administer stem cells without knowing the consequences.

    Just my opinion, and not intending to pick fights with anyone.

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