Pathogenesis of Lipedema: A Hypothesis-Generating Model of Regenerative Imbalance in Adipose Tissue

Lipedema is a chronic adipose tissue disorder characterized by disproportionate and often painful enlargement of the extremities, occurring predominantly in women. Despite increasing clinical recognition, the underlying pathophysiology remains incompletely understood and is likely multifactorial. Existing evidence suggests contributions from vascular alterations, adipose tissue remodeling, inflammatory activation, hormonal influences, and lymphatic dysfunction. This review proposes a hypothesis-generating integrative framework in which lipedema may reflect a regenerative imbalance of subcutaneous adipose tissue. Within this model, genetically and hormonally modulated endothelial permeability could promote activation of perivascular adipose-derived stromal/stem-cell niches and stromal vascular fraction signaling pathways, thereby facilitating coupled angiogenesis and adipogenesis. Progressive adipocyte hyperplasia and hypertrophy may subsequently contribute to inflammatory remodeling, pain generation, and secondary impairment of dermal and subdermal lymphatic drainage. The proposed framework attempts to integrate clinical, histological, imaging, molecular, and endocrine observations into a biologically coherent conceptual model. At the same time, the review emphasizes the current limitations of the available evidence, the heterogeneity of lipedema phenotypes, and the ongoing controversies regarding disease progression, obesity overlap, and the relative role of lymphatic dysfunction. Finally, the potential mechanistic rationale of lymphatic-sparing liposuction is discussed in the context of tissue decompression, restoration of lymphatic transport, and interruption of persistent adipose remodeling. The model presented here should be interpreted as a hypothesis-generating conceptual scaffold requiring prospective validation. Importantly, the present framework should be interpreted as a biologically plausible and hypothesis-generating conceptual model rather than a definitive mechanistic doctrine. Several proposed interactions remain associative and require prospective biological validation.