May 23, 2018
This allograft biopsy shows the characteristic features of adenovirus infection. There is prominent interstitial hemorrhage and edema (Fig. 1), acute tubular injury with viral cytopathic effect and positive immunohistochemical cytoplasmic and nuclear staining for adenoviral antigen (Fig. 2), and foci of tubular necrosis (Fig. 3). The differential diagnosis for this morphology in the transplant setting includes other viral infection (e.g. polyomavirus, CMV, HSV), acute rejection, and drug-related acute interstitial nephritis.