Foreign body reaction to soft tissue filler simulating atypical lipomatous tumor: Report of a case.

Injectable silicone or microimplant has been extensively used for the soft tissue augmentation. Here we report a case of cystic granulomatous reaction to injectable tissue filler, possibly liquid silicone, used for tissue augmentation in the buttocks. Patient presented with a progressive painful swelling in the lower back over L4-L5 and S1 lumbosacral region of 4-month duration. The lump was excised and microscopic examination revealed multiple cystic spaces of variable size lined by foreign body giant cells and macrophages. There were proliferating spindle cells admixed with many multivacuolated mononuclear cells simulating lipoblasts. These morphologic features were highly reminiscent of atypical lipomatous tumor. To our knowledge, this is the second recorded case from the Middle East of such an unusual foreign body reaction. The dermatologists and pathologists should be aware of this unsual lesion. Although rare, this reaction can have important esthetic implication and the patient should be informed about their risk.

A Case of Silicone Granuloma of the Face After Liquid Silicone Injections / 대한피부과학회지

Silicone has become one of the most extensively applied biomaterials in moderm medicine. But, silicone-related diseases are being observed with increasing frequency. We report a case of silicone granuloma of the face in a 44-year-old female patient who had been injected with liquid silicone for cosmetic purpose 20 years prior to visit. The patient presented with erythematous sclerotic plaque and large round brownish patch on the chin and left cheek, respectively. Histopathologically, there were many variable sized ovoid or round cavities surrounded by multinucleated giant cells and lymphohistiocytes. After 6 weeks of oral steroid treatment, mild improvement was noted.

Histopathological Differences between Silicone Granuloma and Paraffinoma

During the past two decades, silicone (polydimethylsiloxane) has become one of the most extensively applied biomaterials. Although pure silicone is relatively inert and usually causes only minimal tissue reactions, it has been reported to evoke a definite foreign body reaction. We studied five cases of silicone-induced granulomas in various sites; two in the breast, one in the breast and axillary lymph nodes, one in the subcutis of the abdomen, back and extremities and one in the eyeball, to illustrate the salient histopathologic features of reactions to silicone with particular emphasis to its differences from paraffin granuloma. For this, 17 paraffinomas were also studied. Tissue reaction to silicone liquid and gel was characterized by numerous round to oval empty cystic vacuoles, mild to moderate fat necrosis, foreign body reaction, a variable degree of mononuclear inflammatory cell infiltration and mild focal fibrosis. The cystic spaces were relatively uniform and showed a snow-man like appearance. In contrast to the silicone granulomas, the paraffinomas, also refered to as sclerosing lipogranulomas showed diffuse sclerosis and frequent calcification around the cystic vacuoles. The cystic spaces in paraffinomas were swiss cheese-like configuration, and the content of the cystic spaces was dirty and frequently calcified. However, there were certain similarities between these two types of granulomas particularly in the early phases of the reaction, therefore, the history of silicone injection or implant, is sometimes critical to the diagnosis of silicone granuloma. Despite great technologic advances in the manufacturing of prostheses and medical equipment, droplets and/or particles of silicone still escape into the body tissues in a variety of ways; therefores, the pathologist should always wonder whether the histologic reaction observed is due to silicone or to some other foreign material including paraffin.