Abnormal lipid storage related to adipocyte shrinkage in acquired partial lipodystrophy (Barraquer-Simons syndrome).

Background: Acquired partial lipodystrophy (APL) is characterized by the gradual symmetrical loss of subcutaneous fat starting from the face, spreading towards the upper part of the body and sparing the lower extremities.

Objective: We report a 33-year-old woman with facial lipodystrophy, loss of buccal fat pads and breast fat tissue. The subcutaneous fat was preserved in other anatomic regions, and we noted some excess of fat accumulation in the lower abdomen and thighs. She had a low serum level of C3 that was positive for a polyclonal immunoglobulin C3NeF in the serum. She was diagnosed with APL.

Methods: We examined fat from lipoatrophic and healthy areas and compared it to subcutaneous fat samples from a healthy control.

Results: Using scanning electron microscopy, we saw shrunken adipocytes with numerous small lipid droplets detaching from the surface of the adipocytes as compared to the classic aspect of adipose tissue in the control subject where the cytoplasm is occupied by one big lipid droplet. A loss of contact between adipocytes was observed in the APL patient when compared to the normal network of adipocytes in the control subject. The healthy fat seemed not affected by lipoatrophy; we observed normal-sized adipocytes, though their surface was not as regular as in the control samples.

Conclusion: The significance and mechanism of the electron microscopic findings are unknown, but they suggest adipocyte shrinkage related to a defect in the retaining triglycerides, which could contribute to the pathogenesis of this disorder.