Quantitative assessment of dermal cellularity in nephrogenic systemic fibrosis: A diagnostic aid

BackgroundNephrogenic systemic fibrosis (NSF) affects patients with impaired renal function who have received gadolinium-containing contrast agents (GCCAs). Increased dermal cellularity is a key diagnostic feature of NSF, however, the histologic findings can be subtle.ObjectiveWe sought to determine whether dermal cellularity in skin biopsy specimens from NSF cases: (1) differs significantly from that of controls; and (2) correlates with duration of the skin lesions, level of plasma creatinine, GCCA dose, or a combination of these.MethodsSeventeen NSF skin biopsy specimens and age-, sex-, and site-matched controls were retrieved from the dermatopathology files of the Massachusetts General Hospital in Boston. Dermal cellularity was manually quantified on hematoxylin-eosin–stained sections and patient medical records were reviewed for demographic and clinical data.ResultsNSF cases showed a mean dermal cellularity of 70.8/high-power field (control mean: 14.4/high-power field, P < .001) and a cut-off range of 19 to 26/high-power field was established. No significant correlation was identified between dermal cellularity and demographic and clinical data.LimitationsIn this retrospective analysis, duration of skin lesion was defined as the interval from most recent prior GCCA study, rather than the actual clinical onset, to time of skin biopsy, and the cumulative GCCA dose may reflect a minimum if GCCA was received at an outside institution.ConclusionEnumeration of dermal cellularity on hematoxylin-eosin–stained sections can aid in the histologic diagnosis of NSF in the setting of chronic kidney disease and GCCA exposure and is independent of patient age, sex, plasma creatinine, time from last GCCA exposure, and GCCA dose.