Muir Torre Syndrome

What is Muir Torre Syndrome?

Muir Torre syndrome, MTS, is a combinated presence of tumours in one individual, linked to genetical mutation. Most commonly, these tumours are on skin , but also on inner organs. Skin tumours are sebaceous adenoma, sebaceous epithelioma, sebaceous carcinoma, keratoakanthoma. Three out of 4 are benign tumours. The tumours that can be found in inner organs are either colorectal, endometrial, or in small intestines or in urinary system.

This syndrome is a form of Lynch syndrome which is more common in human population, but still a rare disease. Muir Torre syndrome is even rarer. Lynch syndrome is a genetical, inherited condition with tumours located mainly in the gastrointestinal tract, but also in some other parts of the body. There are two types of Lynch syndrome. ⁽¹⁾

The type of inheritance Is autosomal dominant, meaning, that one parent is enough as a gene carrier.

Causes

There is an inherited defect in one copy of a DNA repair gene mechanism. This is sufficient to bring imbalance in cell resistance, replication in the DNA and problem with fixing the mistakes. This the cause of neoplastic growth, since there is damage to DNA protection. The genes affected are MLH1, MSH2 and MSH6, but there are also some other genes that could be responsible for the development of tumours. ⁽²⁾

Signs and Symptoms

Sebaceous adenoma is a benign tumour of the sebaceal glands, that produce sebum, which is necessary for skin protection.This tumour may look like acne, but it is persistant. It is a small, yellow bump surrounded with reddish skin. It is usually located on the face. It is the most commonly found tumour in people with Muir Torre syndrome.

Sebaceous epithelioma and carcinoma are malignant tumours of sebaceal glands, and are considered as dangerous for they may spread quickly. The tumours are painless, firm, and present for longer than any other acutely present lesion on the skin. All sebaceal tumours are more frequent on places on the body where the sebaceal glands are in groups: face, neck, chest, shoulders, between the scapulas.

Keratoakanthoma is a benign tumour of the skin, formed from the epithelial skin cells. It appears on skin which was previously exposed to UV radiation, for a long time, for many years. It is significant for its similar look to a carcinoma, which first has to be differentiated. Keratoakanthoma also looks like acne which lasts for a long time. It is a bump with white center and reddish surrounding.

The most dangerous of all is carcinoma, especially on special locations, like eyelid. In that case, the carcinoma may intrude and destruct the orbit or spread in metastases.

Inner organ tumours are less apparent on clinical exam. Colorectal tumours benign and malignant, induce symptoms such as problem with stool discharge, diarrhoea intermittently present with constipation, bledding from the gastrointestinal tract or problems with digestion. These tumours are present in 50% of people with MTS. Tumours of uterus, endometrial tumours include symptoms such as abnormal bleeding, apart from menstruation. Tumours of urinary system may induce blood in urine, pain, frequent infections or problems with urination. ⁽²⁾

Diagnosis

There are criteria by which a person is classified as a possible sufferer from MTS. A person needs to:

• be younger than 60, when the first sebaceal tumour appeared,
• have 1 or more sebaceal tumours,
• and have a family history of Lynch syndrome.

In any presence of skin cancer, or sebaceal tumour, benign or malignant, there needs to be a suspicion about MTS, so it important to check for symptoms and signs of other tumours during clinical evaluation.

Sometimes the blood tests are performed to check for genetical structure. Mutation on MLH1 or MSH2 or 6, speak of possible MT syndrome. However, these mutations aren`t an obligatory finding. In order to find out about the structure and type of a tumour, after the excision, it is important to do a patohystological analysis of the extracted tissue.

Imaging studies include dermoscopy and confocal microscopy and are used for identification of a type of tumour.

The differential diagnosis includes some of the syndromes with familiar genesis and similar pathlogy, for example, neurological tumours with bowel tumours, usually polips. There are possibilities for screening for certain types of tumours: colonoscopy, upper gastrointestinal endoscopy, citology of urine, checking up any suspicious lesion on the skin, pap test for uterus carcinoma, ultrasound for various inner organ tumours, etc. ⁽⁴⁾

Treatment

Treatment is indicated and depends on the type of the tumour. Oral isotretinoin, derivate from the retinoid acid, has shown great benefit in people with this syndrome. According to some studies that evaluated effects, it prevents further development of the tumours. It is sometimes combined with interferon alpha 2a.

Surgical treatment is the only treating option for an existing tumour, and it completely resolves the symptoms if the tumour is benign and there is a possibility of complete excision. Depending on the roots of tumour in the surrounding tissue, aggression of tumour, margins, presence of metastases and state of a patient in general, the prognosis may be different. Sometimes a person needs to undergo more than 30 operations to extract all of the tumours. Cryotherapy (treatment with low temperatures) is also somewhere used. ⁽⁴⁾

Pictures

References:

1. VG., Prieto. Muir-Torre syndrome. emedicine medscape. [Online] 2016. 8 12. [Hivatkozva: 2017. 3 10.] emedicine.medscape.com/article/1093640-overview#a4.
2. Muir Torre syndrome. Rare diseases. [Online] 2015. [Hivatkozva: 2017. 3 10.] httpsÉ//rarediseases.info.nih.gov/diseases/6821/muir-torre-syndrome/cases/30944.
3. Muir-Torre syndrome. Cancer net. [Online] 2014. 9. [Hivatkozva: 2017. 3 10.] www.cancer.net/cancer-types/muir-torre-syndrome.
4. Pancholi A, Collins D, Gandhi P. Muir-Torre syndrome: a case report and screening recommendations. Ann R Coll Surg Engl 90(8). 2008., old.: 9-10.
5. Muir-Torre syndrome-treatment withisotretinoin and interfon alpha 2a can prevent tumour development. Dermatology 200 (4). 2000., old.: 331-3.