ABSTRACT
Metastatic lesions to the colon are far less common than primary tumors. Breast cancer metastasis to the colon is rarely reported, and it is often atypical in presentation and difficult to diagnose. We present a case of a diminutive asymptomatic breast cancer metastasis to the colon found during surveillance colonoscopy in a patient with long-lasting ulcerative colitis, which was initially regarded as a colitis-associated dysplastic lesion. Because early detection of metastatic disease plays a key role in the treatment of patients with breast cancer, a high index of suspicion must be maintained for atypical metastatic presentations to the gastrointestinal tract.
ABSTRACT
Monoclonal antibodies against programmed cell death protein 1 (PD-1) and PD-1 ligand 1 (PD-L1) are the main representatives in the field of immunotherapy and their indications are constantly increasing in medical oncology and hematology during the last decade. They are associated with long-lasting responses and an acceptable toxicity profile, although they may infrequently cause life-threatening complications requiring prolonged hospitalization or urgent interventions. With the current report, we present the case of a 75-year-old woman diagnosed with stage IV lung adenocarcinoma, who developed acute abdominal pain without preceding symptomatology while on pembrolizumab-pemetrexed maintenance treatment. A contained rupture of the appendix was found, for which she was managed conservatively. Subsequent endoscopic as well as histopathological findings from biopsies obtained via colonoscopy associated the clinical and imaging findings with grade 4 immune-mediated colitis. Interestingly, high-grade colitis is more frequent with anti-CTLA-4 agents in comparison to anti-PD-1 agents; moreover, most cases of anti-PD-1-mediated colitis present with preceding symptomatology (like diarrhea or vomiting), while cases or colonic perforation are extremely rare if ever described.
