Bystander LECT2 amyloidosis in tumor nephrectomy.

Pathologic evaluation of the non-neoplastic renal parenchyma in tumor nephrectomy specimens is critical and can detect both renal-limited and systemic pathologies. We report the case of a 69-year-old Punjabi male who underwent cytoreductive nephrectomy for advanced renal cell carcinoma after immunotherapy. We detected clinically unexpected leukocyte chemotactic factor 2 (LECT2) amyloidosis during pathologic analysis of the surrounding non-neoplastic renal parenchyma, which was confirmed by mass spectrometry. LECT2 amyloidosis occurs predominantly in Hispanic patients and has only rarely been described in Punjabi patients. This case highlights the importance of careful pathologic evaluation of the non-neoplastic renal parenchyma of nephrectomy specimens and raises awareness that LECT2 amyloidosis can occur outside of the typical demographic of Hispanic patients.