The impact of lipomatous tumors on type 2 diabetes: are adipose-derived tumors metabolically active?

Background: The metabolic and immunologic properties of adipose tissue are linked to the pathogenesis of type 2 diabetes mellitus. Lipomatous tumors, such as liposarcomas, are rare but can reach significant size. We hypothesized that some lipomatous tumors are metabolically active and can alter systemic glucose homeostasis.

Methods: We performed a retrospective study of patients who underwent resection of a lipomatous tumor at a tertiary cancer referral center (2004-2015). We divided patients into nondiabetics, well-controlled diabetics (hemoglobin A1c [HbA1c] < 7), and poorly controlled diabetics (HbA1c ≥ 7). We compared patient demographics, tumor characteristics, and measures of glycemic control among these groups before and after tumor resection.

Results: We reviewed 217 operations for lipomatous tumors. No differences were observed in tumor characteristics in patients with and without diabetes. However, tumor characteristics differed significantly between the well-controlled and poorly controlled diabetics groups. Patients with poorly controlled diabetes had larger tumors that were more likely to be malignant, retroperitoneal, and well-differentiated. Tumor resection had no detectable impact on diabetes, as assessed by HbA1c, and requirement for diabetic medications.

Conclusions: Poorly controlled diabetes was linked to the presence of large, malignant, and retroperitoneal lipomatous tumors. However, in limited follow-up, no detectable impact of tumor resection was apparent on glycemic control. These data suggest that most lipomatous tumors do not exert a clinically relevant impact on glucose homeostasis.