Apr 30, 2020
Dermatologists play an important
role in disease management for patients with Muir-Torre syndrome
(MTS). In this resident takeover, Dr. Daniel Mazori talks to Dr.
Mohammed Dany about
the pathogenesis of MTS and its
associated malignancies.
“We are the ones who usually make the diagnosis, and we should know
that these patients are at risk for developing several visceral
malignancies and thus require screening,” Dr. Dany explained. They
also review diagnostic clues and tools for dermatologists when
treating patients with solitary sebaceous tumors.
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We also bring you the latest in dermatology news and
research:
1. COVID-19 spurs telemedicine, furloughs,
retirement
2. Evidence on spironolactone safety, COVID-19 reassuring
for acne patients
3. COVID-19 decimates outpatient visits
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Things you will learn in this episode:
- Muir-Torre syndrome is an autosomal-dominant
genetic disorder that predisposes patients to both cutaneous
neoplasms and visceral malignancies.
- Sebaceous tumors are the hallmark of MTS and
are rarely seen outside of this condition: “All three types of
sebaceous tumors can be present in these patients: the adenomas,
the epitheliomas, and the carcinomas,” Dr. Dany explains.
Nonsebaceous skin tumors also can present in MTS, including rapidly
growing keratoacanthomas and basal cell carcinomas.
- Patients with MTS should be further screened
for colorectal, endometrial, ovarian, breast, lung, genitourinary,
hematobiliary, hematopoietic, and central nervous system cancers.
“Every Muir-Torre syndrome patient [also] should definitely see a
dermatologist at least once a year for skin cancer screening,” Dr.
Dany advises.
- In
MTS, germline mutations in DNA mismatch repair genes lead to
microsatellite instability, which drives the formation of tumors;
however, MTS is not always genetic and is not always inherited.
More research is needed on whether specific mutations put MTS
patients at higher or lower risk for developing certain kinds of
tumors.
- All
patients presenting with a solitary sebaceous tumor should be
worked up for MTS. Tumor location can be a helpful diagnostic
indicator. “A sebaceous tumor that is inferior to the neck is most
likely associated with Muir-Torre syndrome; on the other hand,
sebaceous tumors on the head and neck can be either a manifestation
of Muir-Torre but can also be spontaneous,” Dr. Dany
advises.
- The
Mayo MTS score is a helpful tool for risk stratification in MTS
patients. “The score ranges from 0 to 5, and then a risk of 2 or
more has 100% sensitivity for Muir-Torre syndrome and has an 81%
specificity for predicting a germline mutation in the [DNA mismatch
repair] genes,” Dr. Dany explains. Molecular testing should be
performed to confirm the diagnosis.
- Solitary sebaceous tumors in patients with low
Mayo scores may be sporadic; therefore, further laboratory work-up
is recommended to avoid misdiagnosis of MTS.
- Muir-Torre syndrome type 2, also known
as autosomal-recessive
colorectal adenomatous polyposis, is a new subtype of MTS that demonstrates an
autosomal-recessive pattern of inheritance and microsatellite
stability.
- Future research is needed to delineate pathways
for targeted therapies that can shut down the formation of new
sebaceous tumors, particularly sebaceous carcinomas. “If we are
able to find a way to prevent the formation of those sebaceous
tumors from showing up, then we will end up with less follow-up,
[fewer] biopsies, and less concern from our end,” Dr. Dany
explains.
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Hosts: Nick
Andrews; Daniel R. Mazori,
MD (State University of New York, Brooklyn)
Guests:
Mohammed Dany, MD, PhD (University of Pennsylvania,
Philadelphia)
Disclosures:
Dr. Mazori reports no conflict of interest. Dr. Dany reports no conflict of
interest.
Show notes by: Alicia Sonners, Melissa
Sears
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