Rare immune-mediated adverse events in a patient with clear cell renal cell carcinoma treated with pembrolizumab and lenvatinib: a case report

• DOI: https://doi.org/10.22533/at.ed.0159652616042

• Palavras-chave: ...

• Keywords: Immune checkpoint inhibitors; Pembrolizumab; Lenvatinib; Immune-related adverse events; Sialadenitis; Acalculous cholecystitis; Renal cell carcinoma

• Abstract:

  Immune checkpoint inhibitors (ICIs), particularly anti-PD-1 agents such as pembrolizumab, are increasingly used in combination with tyrosine kinase inhibitors for the treatment of metastatic renal cell carcinoma. Although effective, these agents carry a risk of immune-related adverse events (irAEs) that may affect virtually any organ system. We report the case of a 50-year-old male patient with recurrent clear cell renal cell carcinoma (ECOG 1, low-risk IMDC) treated with pembrolizumab 200 mg every three weeks and lenvatinib, who achieved complete oncological response of a metastatic pancreatic lesion. During treatment, the patient developed two rare irAEs: painful immune-mediated sialadenitis (CTCAE grade 2) and necrotizing acute acalculous cholecystitis (CTCAE grade 3). Oral toxicity was initially attributed to lenvatinib-induced mucositis and evaluated by an oncological dentist with no improvement on specific measures, establishing immune-mediated etiology by response to empirical corticosteroid therapy. Cholecystitis progressed despite pulse corticosteroid therapy, requiring laparoscopic cholecystectomy, which revealed a necrotic gallbladder. Postoperative course was uneventful. Both irAEs required prolonged corticosteroid management, with steroid dependency noted for sialadenitis. This case illustrates the multisystemic potential of ICI-related toxicity and underscores the importance of early clinical suspicion, systematic differential diagnosis — including distinction from tyrosine kinase inhibitor toxicity — and multidisciplinary management in patients receiving combination immunotherapy.