In 1967, Muir and Torre each reported patients with multiple cutaneous tumors along with visceral malignancies. Muir-Torre syndrome (MTS) is the combination of neoplasms of the skin (usually sebaceous adenoma, sebaceous epithelioma, or sebaceous carcinoma, but also keratoacanthoma) and a visceral malignancy (usually colorectal, endometrial, small intestine, and urothelial).[1]
MTS has an autosomal dominant pattern of inheritance in 59% of cases and has a high degree of penetrance and variable expression.[2, 3, 4] Relatives of patients should receive genetic counseling.
MTS is considered to be a subtype of hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome).[5, 6] It is associated with an inherited defect in one copy of a DNA mismatch repair (MMR) gene (MMR), which leads to microsatellite instability.[7] The two major MMR proteins involved are hMLH1 and hMSH2. Approximately 70% of tumors associated with the MTS have microsatellite instability. In HNPCC, germline disruption of hMLH1 and hMSH2 is evenly distributed; however, in MTS, disruption of hMSH2 is seen in more than 90% of patients.[8] Two other proteins involved in MTS are MSH6 and PMS2.
The main anomaly detected in MTS patients is the alteration in the MMR genes, particularly MSH2 on chromosome 2 and MLH1 on chromosome 3.[9, 10, 11] Other genes are MSH6,[12] MLH3, and PMS2. Loss of two of the retinoid receptors (RXR-beta and RXR-gamma) seems apparent in sebaceous carcinoma.[13] (See Pathophysiology.)
MTS is a rare disorder,[14] with only a few hundred patients reported. Families with MTS are probably more common than has been reported. Patient age at presentation of MTS ranges from young adulthood to advance age (median age, 53 y).[15] MTS occurs in both sexes, with a male-to-female ratio of 3:2.
Sebaceous carcinoma is an aggressive neoplasm, which can recur locally after excision and can metastasize. When local recurrences develop, they usually do so within the first 5 years of excision. Recurrence rates have been estimated to be around 30%.[16] A two-center study (N = 63; 67 cases; 7 MTS cases) found that independent predictors of recurrent sebaceous carcinoma included noncomplete circumferential peripheral and deep margin assessment methods and large lesion size, but not anatomic subtype or MTS status.[17]
A positive family history of Muir-Torre syndrome (MTS) can be found in roughly 50% of patients. There is an association with a family history of colon cancer, particularly in patients younger than 50 years.
Cutaneous sebaceous neoplasms can precede or follow a diagnosis of visceral malignancy.[18]
MTS is associated with hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome), an autosomal dominant cancer genetic syndrome.[19] The diagnostic criteria (Amsterdam criteria) include the following[20, 21] :
Three or more relatives with an HNPCC-associated cancer (ie, colorectal, cancer of the endometrium, small bowel, ureter, or renal pelvis)
Cancer affecting at least two successive generations
One person with cancer is a first-degree relative of the other two, at least one case of colorectal cancer younger than age 50 years, a diagnosis of familial adenomatous polyposis has been excluded, tumors are verified by histologic examination
Criteria for the diagnosis of MTS include the presence of at least one sebaceous neoplasm (sebaceous adenoma, sebaceous epithelioma, sebaceous carcinoma, and basal cell carcinoma [BCC] with sebaceous differentiation; sebaceous hyperplasia and nevus sebaceus of Jadassohn are generally excluded), along with at least one visceral cancer. Keratoacanthoma, squamous cell carcinoma (SCC), and multiple follicular cysts are sometimes found as well in these patients.
In general, sebaceous neoplasms occurring below the neck are more strongly associated with MTS than those lesions arising around the eye or ear.[22] Non–head and neck lesions are more commonly associated with mutations in the epidermal growth factor receptor.[23]
The skin lesions may precede the presentation of internal malignancy, though they often develop later. Cutaneous neplasms occurring on the face, the trunk, and the extremities are found in various other disorders, including Gardner syndrome, Cowden syndrome, multiple trichoepitheliomas, basal cell nevus syndrome, eruptive keratoacanthomas, and tuberous sclerosis. Many of these syndromes are also associated with visceral tumors.
Sebaceous adenoma is the most characteristic marker of MTS. These fairly rare benign tumors usually appear as yellow papules or nodules in adult patients. In the sporadic cases, most tumors are located on the head (particularly on the face, the scalp, and the eyelids), with the remaining minority scattered over the rest of the body. In MTS, lesions on the trunk may be more common.
The clinical features of sebaceous epithelioma are similar. The nomenclature for sebaceous neoplasms is controversial. Some authors use the term sebaceoma for indolent tumors composed of mature sebocytes and a predominance of undifferentiated basaloid germinative cells. This subset of tumors corresponds to lesions traditionally classified as sebaceous epithelioma.
Sebaceous carcinomas most commonly occur on the eyelids, where they generally arise from the meibomian glands and the glands of Zeiss. They may also occur almost anywhere on the skin, including the ears, the feet, the penis, and the labia. On the eyelids, the tumor appears as a firm yellow nodule with a tendency to ulcerate (see the images below). Clinically, these lesions are often mistaken for chalazia, chronic blepharoconjunctivitis, or carbuncles. Sebaceous carcinoma of the eyelid can invade the orbit and can frequently metastasize and cause death. Extraocular tumors can also metastasize but are less likely to cause death.
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Sebaceous carcinoma of upper eyelid. Image from Mark S Brown, MD, University of South Alabama Medical Center.
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Sebaceous carcinoma as viewed from conjunctival side. Image from Mark S Brown, MD, University of South Alabama Medical Center.
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Gross image of ear resection due to deeply invasive sebaceous carcinoma.
The distinction between sebaceous carcinoma and adenoma/epithelioma is usually based on the architecture of the lesion (infiltrative in carcinoma vs circumscribed in adenoma/epithelioma). However, some lesions may have circumscribed borders but do show frank cytologic atypia,[24] and the authors have seen lesions without any degree of cytologic atypia diffusely infiltrating the subcutaneous tissue.
Keratoacanthoma, whether solitary or multiple, is frequently seen in MTS. It usually starts as a red papule that rapidly grows to become a skin-colored shiny nodule with telangiectases and a central horny plug covered by a crust. Common sites of involvement include the face and the dorsum of the hands, but the lesions can occur anywhere on the body. The tumors have a tendency to regress, ultimately leaving a scar. Those keratoacanthoma cases with sebaceous differentiation are strongly associated with MTS.
The most common visceral neoplasm in MTS is colorectal cancer, occurring in almost one half of patients. The tumors are most commonly located proximal to the splenic flexure. The second most common site is the genitourinary tract, representing approximately one quarter of visceral cancers. A wide variety of other cancers, including breast cancer, lymphoma and rarely leukemia, salivary gland tumors, lower and upper respiratory tract tumors, and chondrosarcoma, have also been reported. Intestinal polyps occur in at least one quarter of patients. Other benign tumors described in MTS include ovarian granulosa cell tumor, hepatic angioma, benign schwannoma of the small bowel, and uterine leiomyomas.
In hereditary nonpolyposis colorectal cancer syndrome (HNPCC; Lynch syndrome), 40% of the germline mutations occur in MSH2 and 35% in MLH1, whereas in Muir-Torre syndrome (MTS), a larger majority have mutations in MSH2. Other markers that may be mutated in a number of cases are MSH6 and PMS2.[26, 27] These mutations in the microsatellite instability enzymes may be detected by genetic studies on peripheral blood or through immunohistochemical analysis of a biopsy specimen.
There is a major problem with immunohistochemical analysis, however, in that mutations are seen in sebaceous tumors in patients without the syndrome. The situation is analogous to testing sporadic neurofibromas for mutations in neurofibromin. The mutations are present in the tumor, even though the patient does not have germline mutation or neurofibromatosis. Likewise, a high proportion of sebaceous adenomas demonstrate loss of MSH2 or MLH1, but very few of these patients will have MTS. If both PMS2 and MSH6 are preserved, however, this is a strong indication that the patient does not have microsatellite instability.[28]
Stool guaiac may be helpful in detecting colonic carcinomas, but colonoscopy will be performed in possible Muir-Torre syndrome (MTS). The tumors may be present at the time of diagnosis, or they may be delayed.[29]
Dermoscopy (dermatoscopy) and confocal microscopy may be helpful in the clinical diagnosis of sebaceous lesions. A review of 20 sebaceous tumors revealed dermoscopic features of radially arranged, elongated crown vessels surrounding opaque structureless yellow areas or yellow comedolike globules and branching arborizing vessels.[30] Confocal microscopy revealed sebaceous lobules composed by clusters of ovoid cells with dark nuclei and bright, highly refractile glistening cytoplasm. These cellular clusters were delimited by a rim of epithelial cells, corresponding to basaloid cells.
Various central nervous system (CNS) neoplasms have been associated with familial nonpolyposis gut carcinoma, and appropriate imaging should be performed in the presence of suggestive signs or symptoms.[31]
Some studies have indicated that examination of the sentinel lymph node may help in detecting early metastasis and therefore may help in staging MTS patients.[32]
Sebaceous adenoma is composed of variably sized, incompletely differentiated sebaceous lobules. Lobules contain basaloid cells at the periphery and mature sebaceous cells, with characteristic cytoplasmic vacuoles toward the center.[33] (See the image below.) Those cases with cystic degeneration are more likely associated with MTS.
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Histologic section of sebaceous adenoma showing predominance of sebaceous cells with prominent cytoplasmic vacuoles.
Sebaceous epithelioma (also known as sebaceoma) differs from sebaceous adenoma mainly in regard to the degree of differentiation. Sebaceous epithelioma lacks the lobular architecture and sebaceous maturation of sebaceous adenoma and contains an obvious preponderance of undifferentiated cells. (See the image below.)
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Histologic section of sebaceous epithelioma showing predominance of basaloid cells.
Sebaceous carcinoma is an outright malignant neoplasm with prominent cellular pleomorphism and anaplasia. Sebaceous carcinomas are common on the eyelid and tend to present with pagetoid extension of atypical sebaceous cells in the conjunctiva or in the epidermis. Occasionally, the tumor invades the adipose tissue of the orbit. A finding of invasion of the subcutaneous tissue favors a diagnosis of carcinoma over that of adenoma/epithelioma. (See the image below.)
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Well-differentiated sebocytes in small nests deeply infiltrating subcutaneous tissue, thus consistent with sebaceous carcinoma.
Immunohistochemistry may be helpful in the differential diagnosis between benign and malignant sebaceous lesions. Carcinomas tend to show strong expression of p53. Interestingly, such lesions appear to show normal nuclear mismatch repair (MMR) protein expression, thus suggesting a different neoplastic pathway.[34] Also helpful may be demonstration of lipid contents in the vacuoles of the sebaceous cells in less differentiated carcinomas. Adipophilin and periplipin are two such antigens associated with sebaceous differentiation.[35, 36]
Keratoacanthoma in MTS often shows the typical histologic findings of sporadic keratoacanthomas, with marked epithelial proliferation and a crater filled with a large keratin plug. Sometimes, sebaceous differentiation can be seen, and such cases are more commonly related to MTS. (See the image below.)
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Low-power view of keratoacanthomalike sebaceous adenoma. Well-circumscribed symmetrical lesion with overlying papillomatosis and prominent hyperkerato....
Particularly helpful in the diagnosis of sebaceous carcinoma is the detection of involvement of the overlying epithelium (either conjunctiva or epidermis), similar to the seen in Paget disease. (See the image below.)
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Sebaceous carcinoma typically infiltrates overlying epithelium similarly to Paget disease. Note in this case how atypical cells have mostly replaced n....
Sebaceous neoplasms, with the exception of sebaceous hyperplasia and nevus sebaceus of Jadassohn, are rare and should signal the possibility of MTS. Screening for microsatellite instability in sebaceous tumors is of value in the detection of inherited DNA mismatch repair defects, which predispose to the various types of internal cancers in persons with MTS.
Kruse et al[37] demonstrated that sebaceous gland tumors frequently have high microsatellite instability in comparison with a variety of other randomly selected tumors and that sebaceous gland hyperplasia rarely exhibits microsatellite instability. Mathiak et al[38] demonstrated that immunohistochemical testing of MTS-related skin tumors for MLH1 and MSH2 is a reliable screening method with high predictive value for the diagnosis of the DNA MMR-deficient MTS.
Ponti et al[39] showed concordance of microsatellite instability and immunohistochemical analysis in patients with MTS. This indicates that the clinical, biomolecular, and immunohistochemical characterization of skin tumors may be used as screening for the identification of families at risk of MTS.
The immunohistochemical demonstration of loss of hMSH2, hMSH6, (rarely) hMLH1, or PM2S is characteristic of MTS and strongly suggests a germline mutation, which may be confirmed by further genetic testing and counseling.[40] The absence of this finding does not exclude MTS, however, and screening evaluation for internal malignancy should still be considered in patients with sebaceous neoplasms other than sebaceous hyperplasia. (See the images below.)
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Normal pattern of expression of MSH-2 (nuclear positivity) in sebaceous carcinoma from patient with Muir-Torre syndrome (see also MSH-6).
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Significant loss of MSH-6 expression in this sebaceous carcinoma in patient with Muir-Torre syndrome.
To illustrate the relative frequency of internal malignancy, in one study, 19 out of 85 patients with sebaceous neoplasm had visceral malignancies, of which 41% were genitourinary. Thirty patients had colonic adenomas and polyps. Ten of the 17 patients with internal malignancy and tissue available (59%) had immunohistochemical loss of MMR protein expression in their sebaceous neoplasms or somatic MMR mutation.[41]
Oral isotretinoin can possibly prevent some of the neoplasms in persons with Muir-Torre syndrome (MTS).[42] A dosage of up to 0.8 mg/kg/day may be effective. A US Food and Drug Administration (FDA)-mandated registry (iPLEDGE Risk Evaluation and Mitigation Strategy [REMS]) was established for isotretinoin products with the aims of managing the risk of isotretinoin’s teratogenicity and minimizing fetal exposure.[43]
Graefe et al[44] noted in a case report that the combination of interferon with retinoids may be promising for prevention of cutaneous tumor development in persons with MTS. They administered interferon alfa-2a subcutaneously in a dosage of 3 × 106 units three times weekly in combination with isotretinoin 50 mg/day and topical isotretinoin gel.
Benign sebaceous tumors and keratoacanthomas can be conservatively treated with excision or cryotherapy. Sebaceous carcinoma should be excised completely and followed for detection of possible metastases.
A case report described the use of the carbon dioxide laser to treat multiple eruptive sebaceous hyperplasia lesions secondary to MTS.[46] The use of a plasma device (Plasma IQ; Berger & Kraft Medical, Warsaw, Poland) approved by the FDA for treatment of skin lesions has been described as successful for MTS.[47]
Patients with MTS should regularly undergo complete examinations, particularly of the gastrointestinal and genitourinary tracts.[48] An annual colonoscopy beginning at age 25 years is desirable because of the high frequency of proximal colorectal cancer. Follow-up care for recurrence or metastasis is mandatory.
What is Muir-Torre syndrome?What is the pathophysiology of Muir-Torre syndrome?What causes Muir-Torre syndrome?What is the prevalence of Muir-Torre syndrome?What are the sexual predilections of Muir-Torre syndrome?Which age groups have the highest prevalence of Muir-Torre syndrome?What is the prognosis of Muir-Torre syndrome?What is included in patient education about Muir-Torre syndrome?Which clinical history findings are characteristic of Muir-Torre syndrome?What are the diagnostic criteria for Muir-Torre syndrome?Which physical findings indicate Muir-Torre syndrome?Which conditions should be included in the differential diagnoses of Muir-Torre syndrome?What are the differential diagnoses for Muir-Torre Syndrome?What is the role of lab testing in the workup of Muir-Torre syndrome?What is the role of imaging studies in the workup of Muir-Torre syndrome?What is the role of sentinel lymph node assessment in the diagnosis of Muir-Torre syndrome?Which histologic findings are characteristic of sebaceous adenoma in Muir-Torre syndrome?Which histologic findings are characteristic of sebaceous epithelioma in Muir-Torre syndrome?Which histologic findings are characteristic of sebaceous carcinoma in Muir-Torre syndrome?Which histologic findings are characteristic of keratoacanthoma in Muir-Torre syndrome?Which histologic finding in Muir-Torre syndrome is similar to Paget disease?Which histologic findings are characteristic of sebaceous neoplasms in Muir-Torre syndrome?How is Muir-Torre syndrome treated?What is the role of surgery in the treatment of Muir-Torre syndrome?What is included in long-term monitoring of patients with Muir-Torre syndrome?What are the goals of drug treatment for Muir-Torre syndrome?Which medications in the drug class Retinoid-like Agents are used in the treatment of Muir-Torre Syndrome?
Victor G Prieto, MD, PhD, Ferenc and Phyllis Gyorkey Chair for Research and Education in Pathology, Professor, Departments of Pathology and Dermatology, University of Texas MD Anderson Cancer Center
Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Myriad / Castle (consultant regarding MyPath test in melanocytic lesions); Orlucent (consultant); .
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Warren R Heymann, MD, Head, Division of Dermatology, Professor, Department of Internal Medicine, Rutgers New Jersey Medical School
Disclosure: Nothing to disclose.
Chief Editor
Dirk M Elston, MD, Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine
Disclosure: Nothing to disclose.
Additional Contributors
Joshua A Zeichner, MD, Assistant Professor, Director of Cosmetic and Clinical Research, Mount Sinai School of Medicine; Chief of Dermatology, Institute for Family Health at North General
Disclosure: Received consulting fee from Valeant for consulting; Received grant/research funds from Medicis for other; Received consulting fee from Galderma for consulting; Received consulting fee from Promius for consulting; Received consulting fee from Pharmaderm for consulting; Received consulting fee from Onset for consulting.
Acknowledgements
The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author, Marcelo G. Horenstein, MD, to the development and writing of this article.
iPLEDGE Risk Evaluation and Mitigation Strategy (REMS). US Food and Drug Administration. Available at https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/ipledge-risk-evaluation-and-mitigation-strategy-rems. December 1, 2023; Accessed: March 11, 2025.
Sebaceous carcinoma of upper eyelid. Image from Mark S Brown, MD, University of South Alabama Medical Center.
Sebaceous carcinoma as viewed from conjunctival side. Image from Mark S Brown, MD, University of South Alabama Medical Center.
Gross image of ear resection due to deeply invasive sebaceous carcinoma.
Histologic section of sebaceous adenoma showing predominance of sebaceous cells with prominent cytoplasmic vacuoles.
Histologic section of sebaceous epithelioma showing predominance of basaloid cells.
Well-differentiated sebocytes in small nests deeply infiltrating subcutaneous tissue, thus consistent with sebaceous carcinoma.
Low-power view of keratoacanthomalike sebaceous adenoma. Well-circumscribed symmetrical lesion with overlying papillomatosis and prominent hyperkeratosis and showing focal sebaceous differentiation (arrows).
Sebaceous carcinoma typically infiltrates overlying epithelium similarly to Paget disease. Note in this case how atypical cells have mostly replaced normal follicular cells and involve overlying epidermis.
Normal pattern of expression of MSH-2 (nuclear positivity) in sebaceous carcinoma from patient with Muir-Torre syndrome (see also MSH-6).
Significant loss of MSH-6 expression in this sebaceous carcinoma in patient with Muir-Torre syndrome.
Sebaceous carcinoma of upper eyelid. Image from Mark S Brown, MD, University of South Alabama Medical Center.
Sebaceous carcinoma as viewed from conjunctival side. Image from Mark S Brown, MD, University of South Alabama Medical Center.
Gross image of ear resection due to deeply invasive sebaceous carcinoma.
Histologic section of sebaceous adenoma showing predominance of sebaceous cells with prominent cytoplasmic vacuoles.
Histologic section of sebaceous epithelioma showing predominance of basaloid cells.
Well-differentiated sebocytes in small nests deeply infiltrating subcutaneous tissue, thus consistent with sebaceous carcinoma.
Low-power view of keratoacanthomalike sebaceous adenoma. Well-circumscribed symmetrical lesion with overlying papillomatosis and prominent hyperkeratosis and showing focal sebaceous differentiation (arrows).
Sebaceous carcinoma typically infiltrates overlying epithelium similarly to Paget disease. Note in this case how atypical cells have mostly replaced normal follicular cells and involve overlying epidermis.
Normal pattern of expression of MSH-2 (nuclear positivity) in sebaceous carcinoma from patient with Muir-Torre syndrome (see also MSH-6).
Significant loss of MSH-6 expression in this sebaceous carcinoma in patient with Muir-Torre syndrome.