Cushing’s tumor tied to inherited Lynch syndrome: Case study
Researchers cite need for early diagnosis, constant monitoring
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Genetic testing showed that a woman with a recurrent pituitary tumor causing Cushing’s disease had Lynch syndrome due to a mutation in the MSH6 gene — the second known case in which the syndrome may have triggered Cushing’s, according to a case report.
Lynch syndrome is an inherited condition caused by mutations in genes involved in DNA repair. People with this syndrome have a much higher risk of developing certain cancers, including colorectal, uterine, and ovarian cancers, because cells can’t correctly repair DNA damage.
“This case underscores the importance of early diagnosis and lifelong monitoring in [Cushing’s disease] … while highlighting a possible association between [Lynch syndrome] and [adrenocorticotropic hormone]-secreting pituitary adenomas,” researchers wrote.
The study, “Recurrent Pituitary Adenoma Causing Cushing’s Disease in a Patient With Lynch Syndrome,” was published in Cureus.
Cushing’s disease is caused by tumors in the pituitary gland, usually pituitary adenomas, that produce excessive levels of the adrenocorticotropic hormone (ACTH). High levels of ACTH trigger the adrenal glands, sitting atop the kidneys, to produce excessive amounts of cortisol. Transsphenoidal surgery (TSS), a minimally invasive surgical procedure to remove tumors in the pituitary gland, is the first-line Cushing’s disease treatment. However, some patients treated with TSS experience disease recurrence, meaning that their tumors come back.
Woman’s symptoms include cold intolerance, moon face
Researchers at Charles University in Prague described the case of a 45-year-old woman with recurrent pituitary adenoma and Lynch syndrome.
The woman arrived at the hospital with a nine-month history of facial redness, abdominal bloating, and decreased cold tolerance. Her medical history included diabetes, high blood pressure, high blood fats, and autoimmune-triggered inflammation of the thyroid.
Doctors examining her found she had the reddish and rounded face typical of Cushing’s, central obesity, and thinner-than-normal arms and legs. Laboratory tests revealed she had high blood sugar, elevated blood and urinary cortisol, and higher-than-normal levels of ACTH.
The clinicians gave the woman medications to reduce her blood pressure and blood fats, and ketoconazole to lower cortisol levels. An MRI scan revealed the presence of a pituitary adenoma, and she underwent TSS to remove the tumor.
Six years later, the tumor recurred, and the woman had a repeat TSS. As her cortisol levels decreased to below the reference range after the surgery, she began treatment with hydrocortisone to normalize those levels.
Ten years after her diagnosis, the woman had another recurrence of the pituitary adenoma and underwent radiosurgery using gamma radiation to destroy the tumor. Four months after the surgery, her cortisol levels were within the normal range. Radiosurgery using gamma radiation for Cushing’s disease is a precise, noninvasive treatment that uses highly focused gamma radiation to target and shrink a pituitary tumor, while minimizing damage to surrounding brain tissue.
“This clinical course underscores the importance of guideline-concordant, lifelong biochemical screening after TSS and the role of targeted radiotherapy when repeat surgery is not curative,” the researchers wrote.
About one year later, the woman was diagnosed with uterine cancer and underwent surgery to remove her reproductive organs (uterus, fallopian tubes, and ovaries) and nearby lymph nodes. Genetic analysis led to a diagnosis of Lynch syndrome caused by an MSH6Â gene mutation.
Doctors recommended an MRI of the pituitary region every two years or earlier if symptoms arise, and regular screening tests for gastrointestinal, breast, urinary tract, and abdominal cancer. They also advised the woman to follow a diet rich in fruit and vegetables, exercise regularly, reduce stress, not smoke, and limit exposure to toxins and sunlight.
The woman’s case is one of two to describe pituitary tumors as the initial manifestation in people with Lynch syndrome, “underscoring that pituitary disease can be the initial presenting feature in [Lynch syndrome],” the researchers wrote. “This case raises awareness of pituitary adenoma occurrence in patients with [Lynch syndrome] and draws attention to the need for larger [group] studies to clarify the association.”
