Pembrolizumab induced gastritis – A case report

Abstract

Renal papillary necrosis (RPN) was first described in autopsy studies. The characteristic pathologic feature is selective coagulative necrosis of the inner medulla and papillae of the renal pyramids. This area of the renal parenchyma is vulnerable to ischaemic injury because its blood supply comes from narrow caliber vessels with low rates of blood flow. RPN represents the end-point of a number of conditions which compromise blood flow or increase metabolic demand in this vulnerable region. Diagnosis of RPN is typically made radiologically and operative management is not usually required. This, coupled with the declining rates of hospital autopsies, mean that RPN is rarely encountered by surgical pathologists. In this work, we present the gross pathological findings and histological features of a case of RPN occurring in a transplanted kidney to raise awareness of this relatively common, but now rarely encountered, entity. The patient is a 58-year-old female with a chronically non-functioning transplant. A CT scan revealed features suspicious for malignancy in the graft, and so it was explanted. Macroscopy showed numerous cystic spaces containing degenerating blood products. Microscopic examination showed necrosis of the renal pyramids, chronic inflammation and fibrosis with no evidence of acute infection or malignancy.