Sir.—Perhaps something was lost during photographic reproduction, but the excretory urogram illustrating the article by Allen et al1 does not show convincing evidence of renal papillary necrosis (RPN). Additionally, the caption of the figure refers to the left kidney but the arrow points to what appears to be a normal composite calyx2 in the upper pole of the right kidney. Were the excretory urograms of all five patients submitted, and were they reviewed by AJDC's radiologic consultants? This is a crucial question, for the diagnosis of RPN hinged on the urographic findings—in none of these five cases was RPN histologically confirmed. A single inadequate figure does not serve to impugn the authors' observations, but if the same equivocacy of interpretation extends to all five cases, then the authors' premise is in doubt.
I appreciate that AJDC's standards for roentgenographic reproduction may be less stringent than