Inflammatory Infiltrating Angiolipoma With an Unusual Plasmacytoid Histiocytic Infiltrate

Infiltrating angiolipoma is an uncommon growth pattern of angiolipoma that typically occurs in the trunk and extremities of male patients during the second and third decades of life.Histologically, it is characterized by mature adipocytes admixed with small-to capillary-sized vascular proliferations and infiltrative margins, often making complete surgical excision challenging.To our knowledge, the inflammatory plasmacytoid morphology observed in the present case has not been previously emphasized in published English-language reports of infiltrating angiolipoma.A 25-year-old woman presented with multifocal infiltrating angiolipomas involving both arms and buttocks, with a clinical history spanning more than 17 years.The lesions demonstrated the characteristic features of infiltrating angiolipoma but were notable for a prominent histiocytic infiltrate exhibiting plasmacytoid cellular morphology, an association not previously reported.Microscopic examination revealed mature adipocytic proliferation with infiltrative growth and associated capillary-sized vascular channels.In addition, a distinctive inflammatory plasmacytoid component was identified throughout the lesion, representing a unique morphologic feature that adds to the known histopathologic cellular variant of infiltrating angiolipoma.We report a rare case of multifocal infiltrating angiolipoma in a young woman with an associated unique inflammatory infiltrate exhibiting plasmacytoid histologic morphology.Recognition of this previously undescribed association may help avoid diagnostic confusion and broaden the current understanding of the morphologic diversity of infiltrating angiolipoma.