A Novel Subtype of Acquired Generalized Lipodystrophy Associated With Subcutaneous Panniculitis-Like T-cell Lymphoma.

Acquired generalized lipodystrophy (AGL) is an extremely rare disease that is characterized by loss of body fat affecting nearly all parts of the body. It is often associated with autoimmune diseases or panniculitis, whereas in other patients the underlying etiology is unclear. We report a 52-year-old male individual who was diagnosed with subcutaneous panniculitis-like T-cell lymphoma (SPTCL) that spontaneously went into remission. Years later he developed new subcutaneous nodules most concerning for relapse SPTCL or lupus panniculitis, followed by onset of hemophagocytic lymphohistiocytosis (HLH) that was treated with allogeneic stem cell transplantation. Notably, around the same time, he also developed generalized subcutaneous fat loss of both upper and lower extremities, chest, abdomen, and face that persisted after treatment of the HLH. Whole exome sequencing was performed to search for pathogenic variants that are associated with SPTCL, including those in hepatitis A virus cellular receptor 2 (HAVCR2), but did not detect any potential disease-causing variant. Our report brings to the attention a novel subtype of panniculitis-variety of AGL. Whether generalized loss of subcutaneous fat in this patient is due to lymphoma-associated panniculitis or due to development of adipose tissue-directed autoantibodies as a paraneoplastic "autoimmune" manifestation of SPTCL remains unclear.