Muir-Torre Syndrome: Symptoms, Genetic Testing, Screening and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is Muir-Torre syndrome?
Muir-Torre syndrome is a rare inherited cancer-predisposition condition in which characteristic skin tumors occur with one or more internal cancers, most often colorectal. It is usually considered a variant of Lynch syndrome and is caused by inherited DNA-repair gene mutations. Evaluation combines skin examination, family history, tissue and genetic testing, and a clinician-guided screening plan.
What the research says
A simple clinical score separated higher- and lower-likelihood patients with sebaceous tumors. In a study that built a scoring system for patients with sebaceous neoplasms, 28 of 29 patients scoring 3 or more had Muir-Torre syndrome, 12 of 20 patients scoring 2 did, and no patient scoring 0 or 1 did (Roberts et al., Genet Med, 2014). [2]
Mismatch-repair staining is widely used, but evidence for using it on every skin tumor is limited. A review found weak to moderate support overall for MLH1, MSH2, MSH6 and PMS2 immunohistochemistry on Muir-Torre–associated skin tumors; in a survey of dermatopathology meeting attendees, 91% of respondents used these tests, mostly when the submitting clinician requested them (Lee et al., J Cutan Pathol, 2017). [3]
Tumor staining can miss an inherited mutation. In a case series of three men with Muir-Torre–associated sebaceous tumors, one man with confirmed MLH1-related Lynch syndrome had a sebaceous adenoma with a false-negative stain; the authors recommend including germline mismatch-repair gene testing in the initial evaluation (Cohen & Kurzrock, Cureus, 2023). [4]
What is Muir-Torre syndrome?
Muir-Torre syndrome (MTS) is a rare genetic disorder that raises the lifetime risk of several cancers. It is defined by the combination of cancerous or noncancerous skin tumors and one or more internal cancerous tumors, often in the gastrointestinal tract. [1]
The skin findings may be the first clue, but they do not always occur at the same time as an internal cancer. A skin lesion can appear before, with or after an internal tumor, and some internal cancers may not cause symptoms right away.
Is Muir-Torre syndrome the same as Lynch syndrome?
In most cases, Muir-Torre syndrome is considered a variant of Lynch syndrome. Lynch syndrome refers to a group of related genetic mutations that can raise cancer risk. Hereditary non-polyposis colorectal cancer, or HNPCC, is another term that may be used for the same condition. [1]
The terms describe related inherited cancer-risk patterns, but an individual diagnosis still requires professional assessment. A genetics professional can explain which gene or syndrome label applies and what it means for relatives. For a broader overview, read our guide to Lynch syndrome.
How common is Muir-Torre syndrome?
Muir-Torre syndrome is rare. Around 200 cases have been recorded, and the condition occurs in about 9.2% of people with HNPCC. It appears to be slightly more common in men than in women, by a ratio of about 3:2. [1]
These figures describe populations and recorded cases, not an individual’s probability. A personal risk assessment depends on clinical findings, family history and genetic testing.
What are the symptoms of Muir-Torre syndrome?
Symptoms include skin lesions and symptoms related to the specific internal cancers a person may have. Skin lesions are often the first symptoms noticed, while internal cancers may not cause symptoms initially. [1]
A skin lesion alone does not establish Muir-Torre syndrome. The appearance, location, growth and tissue findings all matter, and a healthcare provider may recommend further testing. For general background, see our guide to understanding skin lesions.
Sebaceous adenomas
Sebaceous adenomas are the most common skin lesions associated with Muir-Torre syndrome. They are benign tumors arising from sebaceous glands, the oil-secreting glands found in hair follicles. In Muir-Torre syndrome, they often occur on the trunk—such as the chest, abdomen, pelvis or back—rather than only on the head or neck. They may look like small, firm, yellowish or skin-colored bumps.
Sebaceous carcinoma
Sebaceous carcinoma is a cancerous sebaceous-gland tumor. It can resemble a sebaceous adenoma but spreads rapidly and often occurs on the eyelids. It may bleed or produce a crusty discharge. [1]
Keratoacanthoma
Keratoacanthoma is a different type of skin tumor that develops in hair follicles on the head, neck, trunk or arms. It can be cancerous or benign. It typically appears as a small, dome-shaped bump with visible blood vessels and a knobby keratin core. It can grow quickly within weeks, reach up to about 3 centimeters wide, then slowly diminish over several months or years. A person may have one or many. [1]
Fordyce spots
Fordyce spots are enlarged, slightly raised sebaceous glands in hairless areas of the skin, often around the mouth. Some healthcare providers look for them because studies suggest they may occur more often in people with Muir-Torre syndrome. [1]
Skin finding | Description |
Sebaceous adenoma | Usually benign; small, firm, yellowish or skin-colored bumps; often on the trunk in Muir-Torre syndrome. |
Sebaceous carcinoma | Cancerous sebaceous-gland tumor; may spread rapidly, often affects an eyelid and may bleed or crust. |
Keratoacanthoma | Dome-shaped follicular tumor that can be cancerous or benign; may grow quickly and then diminish. |
Fordyce spots | Enlarged, slightly raised sebaceous glands in hairless skin, often around the mouth. |
Which internal cancers are linked to Muir-Torre syndrome?
Muir-Torre syndrome is linked to several internal cancers. Colorectal cancer is the most common and occurs in around half of cases. Stomach, urinary and endometrial cancers are also among the common cancers described. [1]
Cancer type | Symptoms that may occur |
Colorectal cancer | Stomach pain or bloating, changes in bowel movements and rectal bleeding. |
Stomach cancer | Stomach pain, bloating, blood in stool, indigestion, nausea and loss of appetite. |
Urinary cancer | Pain or blood in the urine. |
Endometrial cancer | Lower abdominal or pelvic pain, vaginal discharge or vaginal bleeding. |
Other cancers that may occur include ovarian, prostate, bladder, kidney, penile, testicular, breast, small-intestine, liver, bile-duct, pancreatic, adrenal, lung, blood, brain, laryngeal, salivary-gland and bone-cartilage cancers. [1]
The symptoms in this table are not specific to Muir-Torre syndrome. They are listed to support a conversation with a healthcare provider, not to diagnose a cancer from an online article.
What causes Muir-Torre syndrome?
Muir-Torre syndrome results from a mutation in a gene. Genetic mutations are changes to a person’s DNA sequence that can happen during cell division; when an abnormal cell replicates, it can contribute to disorders including cancer.
Type 1 Muir-Torre syndrome
Type 1 is caused by a mutation in a mismatch-repair gene. These genes help fix errors in DNA. When repair is impaired, abnormal cells can build up in tissues. About 90% of Type 1 cases involve MSH2, although MLH1, MSH6 and PMS2 may also be involved. [1]
Type 2 Muir-Torre syndrome
Type 2 is caused by a mutation in MUTYH, a gene involved in repairing oxidative damage to DNA. Type 2 accounts for up to one-third of Muir-Torre syndrome cases. [1]
Type | Gene pathway |
Type 1 | Mismatch-repair genes; MSH2 is involved most often, with MLH1, MSH6 and PMS2 also possible. |
Type 2 | MUTYH and repair of oxidative DNA damage. |
Is Muir-Torre syndrome hereditary?
Most cases are inherited, although an original mutation can sometimes occur without a known family history. Up to 60% of cases can be traced to a family history of Muir-Torre syndrome, but a family pattern may not be known because not everyone with the mutation is diagnosed.
Some people may have latent Muir-Torre syndrome without symptoms or awareness of the condition. Latent disease has been seen to become active when the immune system is suppressed, including in some people who received solid-organ transplants and took immunosuppressant medicines. [1]
How is it inherited?
Type 1 is autosomal dominant, meaning one copy of the mutated gene can be enough to inherit the condition. If one parent has the relevant mutation, there is a 50% chance of inheriting it, although the way it appears can differ from the parent. [1]
Type 2 is autosomal recessive, meaning both parents must have the same gene mutation for a child to inherit the condition. Parents carrying one copy may have no symptoms and may not know they carry it. [1]
How is Muir-Torre syndrome diagnosed?
A provider may suspect Muir-Torre syndrome when characteristic skin tumors are present, especially when they occur mostly on the trunk or develop relatively young. The provider may ask about symptoms that could suggest internal cancer and about the family history of cancer. [1]
An initial test may involve staining and examining tissue from a skin tumor for specific gene-related changes. This process, called immunohistochemistry or IHC, can help inform whether genetic testing is appropriate. [1]
Genetic testing may use a blood sample to look for mutations in MSH2, MLH1, MSH6, PMS2 or MUTYH. A genetics professional can explain what a positive, negative or uncertain result means for the person and their relatives. [1]
What cancer screening may be recommended?
Healthcare providers recommend regular cancer screenings for people with Muir-Torre syndrome. The exact schedule and combination of tests should come from the treating and genetics teams.
Possible screening and monitoring tests include colonoscopy, upper endoscopy (EGD), prostate examination, mammogram, pelvic examination, Pap smear, urine cytology, liver-function tests, complete blood count, physical examination, skin examination and chest X-ray. If you are preparing for a colonoscopy, see our colonoscopy bowel-prep guide. [1]
Screening or monitoring test | Area it may help assess |
Colonoscopy | Colon and rectum. |
Upper endoscopy / EGD | Upper gastrointestinal tract. |
Prostate examination | Prostate health. |
Mammogram | Breast health. |
Pelvic examination and Pap smear | Pelvic and cervical health. |
Urine cytology | Cells in the urinary system. |
Liver-function tests and complete blood count | Blood and liver-related health monitoring. |
Physical and skin examinations | Overall health and skin tumors. |
Chest X-ray | Chest and lung-related assessment. |
Do not use this table to create a personal screening schedule. Screening depends on age, sex, family history, genetic findings, prior cancers and the advice of the care team.
How is Muir-Torre syndrome treated?
Management focuses on finding and removing cancer when it occurs. People may have regular cancer screenings and biopsies of suspicious tissues. If a cancer is found, it is treated according to its type and stage. Surgical removal is usually the first-line treatment. [1]
Other cancer treatments include chemotherapy, radiation therapy, hormone therapy, immunotherapy, targeted therapy and bone-marrow transplant. Which treatments are relevant depends on the specific cancer and its stage. [1]
An oral retinoid medication called isotretinoin can help prevent new skin tumors. If a colonoscopy finds many colon polyps that raise colorectal-cancer risk, a provider may recommend prophylactic colectomy, which removes part or all of the colon. These decisions require specialist assessment and should not be made from an article alone. [1]
Management component | Purpose |
Regular screening | Helps look for cancers that may be easier to treat when found earlier. |
Biopsy of suspicious tissue | Helps evaluate a suspicious skin lesion or other tissue. |
Surgery | Usually the first-line treatment when cancer is found and removal is appropriate. |
Other cancer treatments | May include chemotherapy, radiation, hormone therapy, immunotherapy, targeted therapy or bone-marrow transplant, depending on cancer type and stage. |
Skin-tumor prevention discussion | Isotretinoin is an option that may help prevent new skin tumors. |
Colon-polyp management | Many polyps may lead a provider to discuss prophylactic colectomy. |
What is the outlook?
Prognosis depends on how many cancers develop and how far they advance. Nearly half of people with Muir-Torre syndrome develop more than one cancer, and more than half develop metastatic cancer. [1]
Cancer associated with Muir-Torre syndrome appears at an average age of 50 and may progress more quickly than in the general population. It may also recur more often after removal, which is why frequent follow-up screenings are important after cancer treatment. [1]
A population statistic cannot predict one person’s future. The most useful discussion is with the treating team, which can interpret the genetic findings, cancer type, stage and treatment response together.
Can Muir-Torre syndrome be prevented?
The inherited condition itself generally cannot be prevented. Not everyone with a mutation develops symptoms, and severity can differ from one biological parent to another. A suppressed immune system has also been observed in association with worse outcomes.
Knowing that a person carries a relevant gene mutation may support genetic counseling and preventive choices. It may also help the person and care team identify and treat cancer sooner, and it can inform reproductive discussions about the chance of passing the mutation to a biological child.
Living with Muir-Torre syndrome
Living with Muir-Torre syndrome can involve regular skin checks, cancer screenings, biopsies of suspicious tissues and conversations about family testing. A written record of genetic results, prior cancers, procedures and recommended follow-up can help keep care information organized.
Because family patterns can be unknown, relatives may benefit from discussing the diagnosis with a qualified genetics professional. The right testing strategy depends on the known mutation, the family history and the person’s clinical findings.
When should you talk with a healthcare provider?
Arrange a healthcare evaluation for a new, changing, bleeding or rapidly growing skin lesion, especially if it resembles the types of lesions described above. Also discuss symptoms such as rectal bleeding, persistent bowel changes, blood in urine, unexplained vaginal bleeding or discharge, or ongoing stomach pain, bloating, nausea or loss of appetite.
If you have a personal or family history of multiple cancers or characteristic skin tumors, ask whether genetic counseling or testing is appropriate. A healthcare provider can determine what needs evaluation and which screening discussions apply.
Questions to ask after a possible diagnosis
A Muir-Torre evaluation can involve dermatology, genetics, gastroenterology, gynecology, urology, oncology or other specialties. These questions can make the conversation more focused.
Question | Why it may help |
Which skin finding prompted concern? | Clarifies what was seen and whether a biopsy is needed. |
Will the tissue be examined with IHC? | Explains the role of an initial tissue-based screen. |
Should I have genetic testing? | Helps determine whether blood-based testing is appropriate. |
Which gene or gene pathway is involved? | Identifies whether the result relates to MSH2, MLH1, MSH6, PMS2 or MUTYH. |
What screening tests are recommended for me? | Converts the diagnosis into a clinician-guided monitoring plan. |
Should relatives speak with a genetics professional? | Helps families understand whether testing may be relevant. |
How should a cancer diagnosis be treated? | Cancer treatment depends on type and stage. |
What follow-up will I need? | Recurrence and additional cancers make ongoing monitoring important. |
Conclusion
Muir-Torre syndrome is a rare inherited cancer-predisposition condition marked by characteristic skin tumors and one or more internal cancers. Colorectal cancer is the most common associated cancer, but several other cancer types can occur.
Diagnosis may involve skin examination, family-history review, tissue testing, genetic testing and regular screening. Management focuses on identifying and treating cancer, monitoring suspicious lesions and tailoring care to the person’s genetic and clinical findings. For more clear, compassionate health explainers, explore Rinnit.com’s health library and bring personal genetic-risk questions to a qualified genetics or oncology team.
Frequently Asked Questions
Is Muir-Torre syndrome inherited?
Most cases are inherited, although a mutation can sometimes occur without a known family history. Type 1 is autosomal dominant, while Type 2 is autosomal recessive.
Is Muir-Torre syndrome the same as Lynch syndrome?
Muir-Torre syndrome is, in most cases, considered a variant of Lynch syndrome. HNPCC is another term that may describe the related condition.
What is the most common skin lesion?
Sebaceous adenomas are the most common skin lesions associated with Muir-Torre syndrome. They are usually benign and may appear as small, firm, yellowish or skin-colored bumps, often on the trunk.
Which cancer is most common in Muir-Torre syndrome?
Colorectal cancer is the most common associated cancer and occurs in around half of cases.
Can a skin lesion confirm Muir-Torre syndrome?
No. Skin lesions can have many causes. A provider may examine the lesion, use tissue testing such as IHC and recommend genetic testing when appropriate.
What genes are associated with Muir-Torre syndrome?
The mismatch-repair genes MSH2, MLH1, MSH6 and PMS2 are associated with Type 1, and MUTYH with Type 2.
What screening tests may be used?
Possible tests include colonoscopy, upper endoscopy, prostate examination, mammogram, pelvic examination, Pap smear, urine cytology, liver-function tests, complete blood count, physical examination, skin examination and chest X-ray. The personal schedule must come from a healthcare provider.
Does everyone with a gene mutation develop cancer?
No. Not everyone with the gene mutation is diagnosed with Muir-Torre syndrome, and people who develop symptoms may have milder or more severe disease than a biological parent.
Can Muir-Torre syndrome be prevented?
The inherited condition itself generally cannot be prevented. Genetic counseling, testing and regular screening may support earlier recognition and informed family planning.
Does Muir-Torre syndrome recur?
Cancers associated with Muir-Torre syndrome may recur more often after removal, so frequent follow-up screenings are important.
References
Cleveland Clinic. Muir-Torre Syndrome: Testing, Symptoms, Treatment. Cleveland Clinic. Last updated May 29, 2023. https://my.clevelandclinic.org/health/diseases/25030-muir-torre-syndrome
Roberts ME, Riegert-Johnson DL, Thomas BC, et al. A clinical scoring system to identify patients with sebaceous neoplasms at risk for the Muir-Torre variant of Lynch syndrome. Genet Med. 2014;16(9):711-716. PMID 24603434. https://doi.org/10.1038/gim.2014.19
Lee JB, Litzner BR, Vidal CI. Review of the current medical literature and assessment of current utilization patterns regarding mismatch repair protein immunohistochemistry in cutaneous Muir-Torre syndrome-associated neoplasms. J Cutan Pathol. 2017;44(11):931-937. PMID 28749576. https://doi.org/10.1111/cup.13010
Cohen PR, Kurzrock R. Germline testing of mismatch repair genes is needed in the initial evaluation of patients with Muir-Torre syndrome-associated cutaneous sebaceous neoplasms: a case series. Cureus. 2023;15(1):e33975. PMID 36824550. https://doi.org/10.7759/cureus.33975
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional with any questions about a medical condition or treatment.
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