An unusual case of an asymptomatic patient with systemic mastocytosis (SM) diagnosed
through a routine colonoscopy has been recently published in Cureus.
SM is characterized by an unusually high proliferation and activity of mast cells. These cells can infiltrate various tissues and release active chemical substances that produce some of the diverse clinical manifestations that affect patients with the disease.
The gastrointestinal (GI) system is a frequent target of the disease; according to some
studies, the incidence of GI compromise in patients with SM is approximately 80%. It can
cause moderate to severe changes in the GI tract surface. Patients can present with
symptoms such as bloating or diarrhea or remain asymptomatic.
Learn more about SM testing and diagnosis
“The subset of SM cases that are asymptomatic and diagnosed incidentally is unknown,”
the authors wrote. “Identifying asymptomatic cases is crucial for appropriately monitoring
disease progression and better managing symptoms when they eventually occur.”
The case involved a 66-year-old woman without any significant GI complaints and an
unremarkable medical history who underwent a routine colonoscopy as part of the
recommended screening schedule for colorectal cancer.
The gastroenterologist discovered three polyps, which were resected and studied under the
microscope. The pathologist observed an abnormal layer of mast cells in all three polyps,
which was later confirmed through specialized immunological tests.
The physicians then repeated the colonoscopy, taking tissue samples from several
segments of the colon. Examination of these samples revealed similar mast cell infiltrates to
those found in the previously removed polyps, which confirmed the diagnosis of SM.
As the patient had no significant symptoms attributable to SM, treatment was considered
unnecessary. However, the patient was advised to carry an epinephrine needle just in case
of an unexpected anaphylactic reaction.
“This case of truly occult disease emphasizes the importance of considering the diagnosis
even without apparent symptoms,” the authors wrote. “ Up to half of SM patients may
experience an anaphylactic reaction at some point, highlighting the need for heightened
diagnostic awareness.”
