Squamous Cell Carcinoma of the Tonsil Causing Small Bowel Perforation in the Setting of Metastasis and Treatment With Programmed Death-1 Inhibitors: A Case Report.

Metastasis of extra-intestinal carcinoma to the gastrointestinal tract (GIT) is a rare event, most commonly occurring with malignant melanoma. Anti-PD-1 (programmed death-1) immunotherapeutic agents are immune checkpoint inhibitors with proven benefit across multiple cancer types, including squamous cell carcinoma of the head and neck (SCCHN). Here we describe a case of small bowel perforation attributed to a primary SCCHN metastasizing to the GIT in the setting of treatment with PD-1 inhibitors.