Submitted by jennlara t3_10gjb3t in askscience
My family and I were talking and my son (9) said he thinks that cancer is always black. I told him that I didn’t think it would be black but couldn’t tell him what color it really is. So we are wondering, what color would cancer cells be?
More so than lungs, he might be getting the black thing from skin and oral cancers, which can often look black, and would be the readily visible cancers. Also black tissue would be associated with necrotic, rotting, just nefarious in general so can see a kid thinking that. But true that in general cancer doesn't have a color.
I was also thinking about necrosis as cancer can lead to necrotic tissue
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My cancerous tumor was a re-occurrence of melanoma. I was given a picture of it. It was pink, like the surrounding tissue.
Just fyi, this was most likely because of certain dyes that are used in patholgy labs. Cells by themselves are colourless unless they contain specific pigments - like black-ish melanocytes.
https://en.m.wikipedia.org/wiki/H%26E_stain
Hope that cancer is gone now.
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Seems like you are in the hands of capable clinicians - I simply wish you all the best.
Thank you.
Natural selection selects for critters to hide from predators, analogous to cancer cells hiding from the innate immune system...
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Stains for antibodies associated with various cancers also stain black after Immunohistochemistry stains and can give this impression.
Especially considering that most finished stains in Pathology are very colorful.
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Also when you look at very advanced breast cancer, some parts are black, I'm assuming from possible necrosis.
So how do surgeons tell cancerous apart from non cancerous when trying to remove cancer? Is it just that cancerous cells (despite looking like normal cells) combine into differently shaped tissue? (Like "lumps"?)
And also how come skin cancer often shows up in "spots" that are differently colored than one's skin?
Surgeons are guided by imaging devices like PET, CT and MRI scanners. You can use contrast agents to show areas of greater glucose metabolism, for instance, as cancer cells use energy faster than others for respiration and blood vessel construction, and draw a contour around that to be used in surgery and radiotherapy.
Physician here. As others have said, Usually through scans and different tools but visually, youre right, its often a "lump" the architecture of tumours are almost always off from normal tissue. Its just rapidly dividing cells going any which way so more often its just a lump. There is often tumour spreading away from that lump too which is harder to see so they cant just go by that of course.
A common skin cancer is melanoma, and those are made specifically from the pigment producing cells in the skin, so they would be hyper pigmented and often dark. Squamous cell and basal cell skin cancers can be any colour really.
They don't actually look like normal cells. Benign tumors do. Cancerous tumors, while still the same color as the tissue they originated from, usually exhibit a bunch of characteristics that are easy to see on a sample under a microscope. That's why biopsies are a common part of cancer diagnosis. After a surgery, the removed tumors borders are examined. There should be healthy cells on all edges to ensure the entire cancerous mass was removed. This might even be done before the patient is closed back up! Cancer cells are a variety of sizes and shapes rather than uniform; they are immature, often looking like cells from an embryo rather than a person who has been born; they lose their specialized features that allow them to do whatever their function is; they have multiple large nuclei (the part of the cell that holds DNA,) and that DNA is tangled; they contain less fluid; they have more blood supply growing, and they aren't attached properly to each other or surrounding tissues.
And skin cancer might appear darker because your skin is made of different types of cells. If the pigment producing cell (melanocyte, the cell that gives your skin it's color) is the cancerous one, you get a bunch of pigmented cells clustered together and it's darker than the surrounding skin cells that don't make pigment.
not a surgeon/medical provider
From what I've heard, a tumor looks/feels different from normal tissue. Dr. Sandra Lee (aka Dr Pimple Popper) has a few videos on lipomas (a non-cancerous tumor) and I believe at least one has an explanation.
I don't know the answer to your question regarding skin cancers, with the exception of melanoma, which is a cancer of the pigment-producing cells in your skin. This makes it very easy to differentiate on lighter-skinned folks as it is physically darker than the surrounding normal skin.
Cancer cells often do look different than the originating tissue, and can have distinct histologic markers on the microscope.
Yes thank you! I told him that gangrene is black, but I didn’t think cancer was. So when he asked what color it would be I was stumped.
What colours are brain, heart, liver, etc cells normally?
I recently started wondering this because someone said “liver coloured” and I think they meant the purple that livers are usually coloured in text books. I realised books have standard colours for organs and now we think those are the colours but obviously they are just for clarity
Most organs consist of more than one cell type. Fatty tissue is white to yellow. Muscle cells are red meat, looks the same in all mammals. As the heart is a muscle too, it's mostly red, with a bit of fat around it, and some shimmering white to almost silver connective tissue. Fasciae in general are really pretty. The single fiber is white, but in smooth organized sheets they can shimmer like pearl in pale rainbow colors.
White blood cells are translucent, only the red blood cells are actually red, platelets are yellow. White blood cells climb around in almost all tissues, so even a red muscle has some of those, and yellow-ish nerve fibers and the red-grey-white of blood vessels, it's a mix.
When you put any cell under a microscope most of them are translucent and barely visible. There are a bunch of organelles inside, filled with whatever this cell's product/purpose is. That's where the color comes from. Like chloroplasts in plant cells, just those are green, the rest is translucent. Few cells are so colorful that it's noticeable when you look at just one. The sheer mass of them makes organs as colorful as they are.
To really tell things apart the cells are dyed. There are different dyes/stains that attach to different parts of a cell. They even come in fluorescent. Some are as simple as binding to anything acidic or basic, others cling to just one specific molecule. Without dye it's hard to impossible to tell what is what.
Pretty much every part of the body has a colour some where along a spectrum between a yellowish off white to a dark, almost blackish red. Textbook images of cells from different organs will have been stained with different dyes to make the cell organelles more clear. The most common stain will probably be the H&E stain which makes everything look pink and purple.
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Is it possible to distinguish a lone free cancer cell from a healthy functioning one under a microscope?
Don't some cancer cells undifferentiate?
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I've seen a sample of al dental tumor cells being metastasised into a kidney. Yes, those were actual molars growing out of a kidney. Those cells were pretty white.
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I always assumed they'd be white because that's how they look on a scan, but then I watched a documentary where they autopsied a cancer victim on camera (yes, really) and was surprised when the tumours didn't look noticeably different from the surrounding tissue. But you're right, when you think about what cancer actually is, why would they look different?
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There actually are some ways you can tell cancer cells from non-cancerous cells using color/appearance! Cancer cells generally have a higher nuclear/cytoplasmic ratio than non-cancerous cells. In other words, in cancer cells the cell nuclei are larger compared to the size of cell they’re in. This can be seen under a microscope, but the difference between nucleus and cytoplasm is hard to see with its ‘natural’ colors. But you can see the difference if you use dyes which color the nucleus one color and the cytoplasm another.
The cell also has various optical properties which are subtle or otherwise not visible to the naked eye which can be used to visually distinguish cancerous and normal cells. For example, human tissues is fluorescent. If you shine light at a specific wavelength (often in the UV) the tissue lights up (fluoresces) at a different wavelength (color). Cancer cells have different fluorescent properties than normal cells, and this can be seen using a specialized microscope.
You can also apply dyes to make cells and their structures more easily visible. There are certain dyes which will stick to cancer cells but not non-cancer cells. These can be used to make it relatively easy to spot cancerous tissue. However this requires a dye to be applied which can be impractical depending on how toxic the dye is, where the site is in the body (inside of the mouth is way easier to get a microscope and dye in than inside the heart for example)
Thank you! I had no idea how to answer him so this helps!
surgical tech here. I can't tell you about the color of individual cells nor how they are stained by pathology, but I can describe what the specimens look like as soon as they come out of the patient.
normal vocal cords are shiny, whitish-yellow, and have clearly vertical capillaries.
squamous cell carcinoma, when it grows on them, is flat and white with an uneven surface. you can usually see thinner patches around the mass where the normal vessel pattern turns pebbly or foggy.
normal brain tissue is pink and has large, obvious vessels all over the surface like a cartoon. the dura is white, smooth, and normally does not adhere to the brain at all. it can stick to the skull a little but is easily freed.
the brain tumor itself looks and feels exactly like uncooked tofu. it's soft, spongy, white, saturated, and falls apart easily. Larger brain tumors can compress surrounding healthy tissue until it dies, so many times the tumor is surrounded by watery greenish-yellow or brown-tinged CSF. if the tumor is near the dura, sometimes it can grow through it and stick to the inside of the skull.
meningioma, glioma, and pituitary tumors all look similar to me, but maybe someone more experienced could tell you the subtle differences better.
normal muscle has gorgeous bands of silvery fascia over rich maroon. it makes you think, "just like in the textbook!" Myoma (muscle tumor) is matte, uniform, and featureless. spongy and firm to the touch but doesn't fall apart when you squeeze it. like a chicken tender without the skin. I've seen one from a thigh that was terra-cotta colored, and the ones that grow in the uterine wall (fibroids) are the same texture but off-white, kinda yellow.
that's about the extent to which I can speak from my experience! Cancer is more obvious to identify by touch than by color.
tl;dr: Usually white.
Wow that’s really super interesting though! I wish I had the tenacity to be able to go into the medical field because it is so interesting. Thank you for your response!
> tl;dr: Usually white.
Since the context of the question was cells rather than tissue, I'll note that "white" often arises from an agglomeration of many clear/transparent things: salt, sugar, milk, snow, etc. All the single eukaryotic cells I've examined via microscopy have been essentially transparent. (In fact, quite sophisticated methods are necessary to discern many features in the living, unstained cell.)
oh, that is true, thanks for adding this. I don't get to see any of what goes on in the histology lab, but I'm definitely gonna dig into that article to learn more c:
Cancer is going to be whatever color tissue it originated from. Liver cancer is probably going to be the color of a liver. Brain cancer, brain color, etc etc. Cancer is just cells in tissue that are growing out of control and taking extra resources from the body to sustain itself, that's all. They're practically normal cells otherwise.
Agree with this. Just want to add two things:
Advanced stage cancer tumors can become necrotic which can lead to discoloration.
And the common skin cancer melanoma means 'cancer arising in melanocytes' which are melanin-pigment producing cells. So these skin cancers (pathological overgrowth of melanocytes) often do look very dark or black, regardless of your normal skin tone.
Thank you so much! This really helps as I had no idea what to tell my son.
Additionally the cancer you can see on your skin can be pearly, red, or with melanoma black. The worst skin cancer is melanoma.
It depends on the type of cancer. My mom had a neuroendocrine tumour which showed an iridescent rainbow of colours. Nasty thing secreted adrenaline which caused a constant fight or flight response in her which in turn caused strokes and heart attacks. I don't know what other cancers look like.
Cancer cell biologist here. Cancer cells, as others have mentioned, are just cells that are dividing uncontrollably. Some cancer cells will be pigmented, if they're derived from cells that produce pigments, but most are clear and have no discernible color.
For example, various types of skin cancer will be pigmented because skin can produce melanin. In this case, they'll look brown, tan, or black. But, something like bone cancer will be clear under the microscope.
While you can detect cancer cells based on their shape and the shapes of their innards, this typically requires various stains, eg, a stain that specifically colors DNA so you can see the shape of the nucleus.
If you or your son have more questions, feel free to DM me!
This is so sweet! 🥹 Thank you! I really like talking to my kids on things of the world and it helps us all learn a little!
It can be lots of different colors! Some of them can appear off-white/yellowish.
If you aren't squeamish, go to Google images and search "______ cancer gross pathology " (e.g., breast cancer gross pathology). In this context, gross means what's visible to the naked eye -- though some may think it's just gross lol.
You've gotten lots of good comments describing what tumors look like, but if you're wondering what color the actual cells are, the answer is that they are usually off-white (just like most cells in the body, which cancer cells derive from). The colors others are describing in solid tumors or organs are usually due to the presence of different types of cells (like red blood cells) or certain fluids (like the yellow of bile). If you were to remove the tumor, squish it up and take out just the cancerous cells, to the naked eye they would most likely appear off-white.
> to the naked eye they would most likely appear off-white.
Single cells would appear clear. Agglomerations of many, many cells would appear off-white for the same reason that milk or snow appears off-white: indiscriminate scattering of white light.
Single (human) cells wouldn't appear as anything to the naked eye. Unless your naked eye is a microscope, which would be dope.
I’m referring to a monolayer.
Thank you so much!
As a pathologist: “blue is bad”. We use stains when looking at the cells under the microscope and essentially comes down to blue and pink (hematoxylin and eosin). Pink stains the cells cytoplasm and blue stains nucleic acids/nucleus. Usually cancer cells have a larger nucleus compared to the rest of the cell and making the tumor appear more blue.
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I work in cancer research where we inject different types of cancer cells into a mouse to grow. When extracting the tumor, almost all of them just look like a squishy tan blob. Some are darker or lighter depending on the type of cells and angiogenesis (ability to grow blood vessels from existing vasculature).
Generally, the same colour as normal cells. They’ll look pretty similar to whatever tissue/organ the cancer cells originate from.
It’s really quite tricky to tell the difference even under a microscope. You have to be pretty well trained to do it.
Grossly (with your bare eyes) tumours are usually white/yellow and hard compared to the surrounding tissue. There is obviously lots of variation but generally that’s what we see in pathology. Skin specifically has more colour variation than others (colon, breast, oral).
Many kinds of cancerous tumors appear whiter than healthy tissue on the inside of the mass. Some bloody or necrotic masses can appear black but that’s not really the cancerous cells causing the color. In general most cancerous cells look like an off-white color
Not an expert here, but as a cancer survivor I've had lots of meetings with doctors, oncologists, geneticists, etc. I've been told that cancer cells do turn black. I think it depends on the age of the cell though. Every cell in your body basically has a "kill switch" that causes the cell to die under various circumstances. When cancer occurs, it's because the gene for that kill switch is damaged, so basically the cell cannot die and just keeps dividing. After time, that cancer cell will continue to grow and eventually turn black.
I had colon cancer that spread to my lymph nodes. When my lymph nodes were removed, the cancerous ones did look black, according to my surgeon.
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As a little extra, to completely confuse you, I know everyone said cancer cells are colourless which is true but I grow and extract tumours from mice and chicks regularly and tumours when extracted can be anywhere from pink to purple to milky white and opaque. Depends on the organism and the cancer cell type and treatment or lack thereof.
Thank you! I really wasn’t sure how to answer him, I just knew they weren’t black.
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Wrong question. Cancer cells are identified visually by other abnormal features of the cells related to their nucleus, vacuoles, and granules and how those features different from normal cells and how many and where the cells are. The nature of the cells is further clarified by flow cytometry which identifies surface protein markers of the cells the pattern of which can tell you if the cell is abnormal or immature. Leukemias are often first identified by the presence of immature white cells in the peripheral blood or an abnormal quantity of certain types of white cells. All immune cells in your blood appear white when separated from rbcs, but when looked at under the microscope they are stained and appear with dark blue nucleuses and blue to pink or red cytoplasm.
Let’s no go crazy on the verbosity. It’s a 9-year old. We have been programmed to associate cancer with cigarettes and tar. (Not necessary a bad thing).
Just give him a new paw patrol toy….or, if you want to really be effective, let him watch “Cell at Work” or if you’re really daring “Once Upon a Time…Life”
If kids ask questions, they should get honest answers. They understand (or are capable of understanding) a lot more than most adults give them credit for -- as long as you're willing to answer a lot of questions and make a decent effort with them. There's no need to hand out toys to distract them.
ThoughtfulPoster t1_j53cw2k wrote
Cancer is not a type of cell. It's a word for any type of cell that isn't listening to its programmed instructions to stop diving and die (apoptosis) after it stops being useful to the body. So, brain cells that become cancerous look like brain cells. Heart cells that become cancerous look like heart cells. And so on.
Your son is probably confused because we often show children pictures of soot-damaged lung tissue and talk about how smoking causes cancer, so it's easy to think that those pictures are "what cancer looks like." But no, cancer cells look like any other, usually.