Conclusion:
LS accounts for 3-5% of all colorectal cancers. Two different variants
of LS have been discovered, MTS and TS. In this paper, we focus more on
MTS, which is characterized by diagnosis of at least one sebaceous
(adenoma, carcinoma, and epithelioma) or keratoacanthomas skin neoplasms
and at least one visceral malignancy. The tumors can precede, coincide,
or follow the visceral malignancy. In our proband, it followed her
visceral malignancy. She also displays autosomal dominant inheritance
likely inherited from her maternal grandmother. Genes commonly mutated
in MTS include MLH1, MSH2, MSH6, and PMS2, the same gene mutations seen
in Lynch Syndrome. MTS is seen in 9.2% of patients with Lynch Syndrome
[5]. Treatment for MTS consists of surgical excision or Mohs
micrographic surgery for the skin lesions. Oral isotretinoin alone or
with interferon-alpha has been shown to suppress new development of
sebaceous neoplasms in MTS [6]. Annual skin checks are recommended
for continued monitoring for any new skin carcinomas.
Along with managing the skin carcinomas, the various cancers caused by
LS must also be managed in these patients. It is recommended that
patients with LS undergo annual surveillance colonoscopy from age 25, or
2-5 years from the age of the earliest family member diagnosed before 25
years old [7]. Females diagnosed with LS are recommended to have
annual pelvic exam, transvaginal ultrasounds, and in office endometrial
biopsy starting at the age of 30-35, it is also recommended that females
with LS undergo prophylactic hysterectomy and bilateral
salpingo-oophorectomy as a prevention strategy [8]. Annual upper
endoscopy with biopsy of gastric antrum is recommended starting also at
age 30-35. Treatment of LS is specific to the cancer the patient
develops. Treatment can consist of surgery, chemotherapy, and radiation
therapy.
In this case, we presented a patient with the Muir-Torre variant of
Lynch Syndrome. She originally presented with abdominal pain secondary
to left sided metachronous colon cancer. She would then have endometrial
cancer. Her history met the Amsterdam II criteria to be screened for LS
and her genetic testing revealed mutation of the MSH2 gene. The MSH2
gene accounts for 38% of the gene mutation associated with LS [1].
She also would later be diagnosed with skin cancer (squamous cell and
sebaceous), and peritoneal cancer respectively. Her diagnosis of
sebaceous carcinoma that presented back in 2008 would further specify
her LS diagnosis as MTS. Considering squamous cell carcinoma is her most
dominant skin cancer, her case is not the typical presentation of MTS as
that is characterized more by sebaceous (adenoma, carcinoma, and
epithelioma) or keratoacanthomas skin neoplasm. However, she still meets
qualifications required for MTS due to having at least one sebaceous
carcinoma along with colon cancer. This patient is currently doing well
and continues to receive treatment for her squamous cell carcinoma and
IVIG infusions for her immunosuppression. At the age of 67, she
demonstrates the high long term survival rate for patients with MTS or
LS, as tumors can be monitored with preventative care and are responsive
to treatment. Her case also demonstrates the importance of continuous
monitoring of all types of cancers in this patient as an atypical cancer
for LS can be typical for its variants.