Pathological pseudoprogression to anti-PD-1 inhibitor in metastatic periampullary carcinoma: Case report

Pseudoprogression has been deemed as a rare clinical phenomenon during the treatment of immune checkpoint inhibitors in patients with advanced cancers, especially in periampullary carcinoma, however, leaving potential molecular mechanism remain unknown. PATIENT CONCERNS: Regular examination after radical pancreaticoduodenectomy because of periampullary carcinoma. DIAGNOSES: Recurrent periampullary carcinoma with metastasis in liver. INTERVENTIONS: Regimens of XELOX (oxaliplatin at a dose of 130 mg/m(2), day 1 and oral capecitabine at a dose of 1000 mg/m(2) twice a day, day 1–14, every 21 days), and tislelizumab at a dose of 200 mg, day 1, per 21 days, was prescribed as palliative treatment. OUTCOMES: Pseudoprogression and symptom of hair and mustache repigmentation were also observed, which resulted in partial response finally. LESSONS: Results of the present case suggested that pseudoprogression, along with hair and mustache repigmentation, possibly caused by anti-PD-1 inhibitors, may also happen in patients with periampullary carcinoma, which should be paid attention to. The potential mechanism should be further investigated.