Incidence of Paradoxical Adipose Hyperplasia After Cryolipolysis: A Systematic Review and Meta-Analysis

Paradoxical adipose hyperplasia (PAH) is a rare complication of cryolipolysis, characterized by an unexpected overgrowth of adipocytes in the treatment area. Emerging literature suggests that PAH may be underrecognized and underreported. Because of the increasing popularity of cryolipolysis for nonsurgical fat reduction, we sought to identify the overall incidence of PAH as well as the incidence by sex and treatment device, time to diagnosis, and any additional complications of cryolipolysis. In this systematic review and meta-analysis, databases (MEDLINE, Embase, CINAHL, Web of Science, Scopus, and CENTRAL) were searched from inception to May 11, 2025, for studies reporting on PAH incidence in cryolipolysis patients. The primary outcome was the literature-pooled PAH incidence, estimated using a nonpairwise generalized linear mixed model for meta-analysis. Secondarily, we descriptively reviewed treatment devices utilized, time to PAH diagnosis, and additional cryolipolysis complications. Twenty-eight studies encompassing 13,078 patients were included in the review. Low-certainty evidence suggested that the pooled incidence of PAH was 0.22% (95% CI, 0.10-0.47), with 29 cases identified (1 in 455 patients). Sex-based risk differences were not statistically significant. Only 4 studies reported sufficient follow-up duration (≥16 weeks). PAH cases were reported with various devices and applicators, and although 10 of the 29 PAH cases (34.5%) involved the CoolCore applicator, insufficient data precluded device-based meta-analysis. Overall, the incidence of PAH following cryolipolysis appears to be higher than manufacturer reports. These findings emphasize the need for comprehensive risk disclosure, improved awareness and adverse event reporting, risk factor identification, and further investigation into the pathogenesis of PAH. Level of Evidence: 3 (Therapeutic).