Abstract: SA-PO1092
Paraneoplastic Cast Nephropathy Associated with Secretary Pancreatic Carcinoma
Session Information
- Pathology and Lab Medicine: Clinical
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1502 Pathology and Lab Medicine: Clinical
Authors
- Wehbe, Edgard I., Wichita Nephrology Group, Wichita, Kansas, United States
- Said, Samar M., Mayo Clinic, Rochester, Minnesota, United States
- Nasr, Samih H., Mayo Clinic, Rochester, Minnesota, United States
Introduction
We report the case of a patient with pancreatic mixed acinar-neuroendocrine carcinoma who presented with irreversible acute kidney injury ( AKI ) due to myeloma-like cast nephropathy. We performed proteomic and immunohistochemical studies which revealed that the AKI was triggered by tubular obstruction by acinar cell carcinoma-secreted proteins. A novel pathomechanism for carcinoma-associated nephropathy is being described.
Case Description
A 64-year old male was found with a large abdominal mass after workup for unintentional 35 pound weight loss over 6 month period. Biopsy of the mass showed pancreatic mixed acinar-neuroendocrine carcinoma. He developped AKI after the diagnosis. Urinalysis showed 1 + protein but no hematuria. Serologies were negative. Serum protein electrophoresis with immunofixation did not show monoclonal protein and serum free kappa/lambda ratio was normal. Kidney biopsy showed myeloma-like cast nephropathy. He was initiated on hemodialysis and received rescue plasmapheresis without success in renal recovery. He received gemcitabine and Abraxane with no improvement in his condition. He remained on dialysis, had a decline in his clinical condition, developed severe refractory septic shock and died 4 months after cancer diagnosis.
Discussion
Kidney biopsy showed acute cast nephropathy with many distal tubular PAS-negative and trichrome-polychromatic casts, associated with mononuclear and giant cell reaction, acute tubular injury, and mild interstitial inflammation and fibrosis . Ultrastructurally, the casts were electron dense and some were admixed with fibrillar uromodulin casts. The casts did not stain for kappa or lambda on immunofluorescence. Analysis by laser microdissection/mass spectrometry and by immunohistochemistry detected large amounts of two acinar-cell specific proteins, , REG 1α and CPA1, in the renal casts and the patient’s pancreatic carcinoma cells. Thus, the acute kidney injury in this patient is likely due to distal tubular obstruction by aggregates of filtered carcinoma-secreted proteins and uromodulin, with subsequent tubular injury, interstitial inflammation and fibrosis, as has been proposed in myeloma cast nephropathy. This case describe a new mechanism for paraneoplastic cast nephropathy in the absence of multiple myeloma.