Clinical, pharmacologic, and pathologic studies were performed on three patients with multiple painful angiolipomas. Injection of the tumors with vasodilators, vasoconstrictors, mast cell degranulators, and histamine did not produce pain in the lesions. Heat, cold, and venous occlusion also did not cause discomfort. Large myelinated nerves were found in the connective tissue surrounding the angiolipomas, but Bodian stains were negative on the tumors. Numerous mast cells were found in the angiolipomas, and release of histamine from these cells may play some role in the development of vessels within the tumors, but it does not account for the painful nature of the lesions. Unlike the solitary unencapsulated angiolipoma, multiple subcutaneous angiolipomas are benign neoplasms that show no malignant or locally invasive potential.
Belcher RW, Czarnetzki BM, Carney JF, Gardner E. Multiple (Subcutaneous) AngiolipomasClinical, Pathologic, and Pharmacologic Studies. Arch Dermatol. 1974;110(4):583-585. doi:10.1001/archderm.1974.01630100043010