Combination therapy with toripalimab and lenvatinib in metastatic type 2 papillary renal cell carcinoma: a Case Report.

BACKGROUND

Type 2 papillary renal cell carcinoma (PRCC) is an aggressive subtype of renal cell carcinoma with a poor prognosis. Diagnosis is challenging, particularly when presenting as a metastatic lung mass. This report describes a case of metastatic type 2 PRCC treated with first-line toripalimab (anti-PD-1) and lenvatinib (multikinase inhibitor), highlighting sustained clinical benefit.

CASE PRESENTATION: A 73-year-old man presented with cough, hemoptysis, and a large left lung mass initially misdiagnosed as primary lung cancer. Multidisciplinary re-evaluation, including immunohistochemistry (PAX8+, P504s+, also known as AMACR), confirmed metastatic type 2 PRCC. After 11 months of toripalimab (flat dose of 240 mg every 3 weeks) and lenvatinib (flat dose of 8 mg daily), serial imaging demonstrated partial response (PR) with regression of pulmonary metastases, lymphadenopathy, and obstructive pneumonia. No serious adverse events occurred.

CONCLUSIONS

This case underscores the potential efficacy and tolerability of toripalimab-lenvatinib combination therapy in metastatic type 2 PRCC. Further clinical trials are warranted to validate this approach.