Dominic S. Raso

Silicone Breast Implants: Pathology

Questions as to the bioreactivity of silicone breast implants (SBIs) have recently been intensely scrutinized, most notably by the media and legal system. Pathologists must be aware of the controversy and treat each SBI and associated tissue as a potential lawsuit. Grossly, silicone is a clear, viscous substance that may be observed either within or extruding from a silastic bag. By light microscopy, silicone is a nonstainable, nonpolarizable, refractile substance. Thicker sections, especially when viewed by non-Köhler illumination, phase-contrast, and darkfield microscopy will enhance visualization. Ultrastructurally, silicone is an electron-dense, amorphous substance often located within phagocytic vacuoles or extracellularly within the stroma. Correlating electron probe microanalysis allows for reliable identification. In most cases, a fibrous capsule surrounds the SBI, with the interface lining varying from a virtually acellular to a synovial-like lining composed of phagocytic and secretory cells. Silicone can often be identified within the fibrous capsule and also in distant tissues biopsied for suspected autoimmune disorders, such as synovium, skin, and lymph nodes, often without ultrastructural evidence of cytologic effects. This study has demonstrated that silicone accumulates at distant tissue sites due to preexisting inflammation acting as a stimulus. Thus, silicone is not a primary inducer of inflammatory disease processes. These findings are supported by various large epidemiologic studies.

Immunolocalization of keratan sulfate, chondroitin-4-sulfate, and chondroitin-6-sulfate in periprosthetic breast capsules exhibiting synovial metaplasia.

The distribution of various proteoglycans and basement membrane components within 10 breast capsules with synovial metaplasia was assessed immunohistochemically. Immunoreactive keratan sulfate and chondroitin-4-sulfate were present in many of the synovial metaplasia lining cells, suggesting active secretion of these proteoglycans into the intraprosthetic space. In contrast, chondroitin-6-sulfate was confined to the extracellular matrix of the underlying supporting fibrous capsule. Type IV collagen and laminin were not associated with the synovial metaplasia lining, thus confirming the absence of a basement membrane, as previously indicated by morphologic analysis. As with tendon reconstruction, the development and maintenance of a synovial metaplasia lining that secretes lubricating factors such as proteoglycans may be beneficial for decreased capsular contracture.

Caterpillar bodies of porphyria cutanea tarda ultrastructurally represent a unique arrangement of colloid and basement membrane bodies

Caterpillar bodies are eosinophilic, periodic acid-Schiff (PAS)-positive globules arranged in a linear fashion in the epidermis overlying subepidermal blisters of porphyria cutanea tarda (Am J Dermatopathol 1993;15:199-202). We retrospectively studied by transmission electron microscopy nine cases of porphyria cutanea tarda (PCT) that demonstrated caterpillar bodies. We identified three components of the eosinophilic bodies: degenerating keratinocytes, colloid bodies, and basement membrane bodies. The colloid bodies consisted of whorled masses of filaments containing degenerating melanosomes, vacuoles, mitochondria, and desmosomes. Basement membrane bodies were composed of convoluted basement membrane material and associated collagen. Both colloid and basement membrane bodies were often associated with degenerating keratinocytes, were located both intra-and extracellularly, and were occasionally fused to one another. We believe that caterpillar bodies are a combination of degenerating keratinocytes, colloid bodies, and basement membrane bodies formed by repeated blistering and reepithelialization with transepidermal migration. Furthermore, we believe that caterpillar bodies are a diagnostic clue for the diagnosis of PCT.

Fatal suture embolism to the left anterior descending coronary artery. A case report and review of the literature.

A variety of emboli may be encountered at autopsy. While pulmonary thromboemboli are a relatively common cause of sudden “natural” death, the medical examiner may discover more exotic emboli during the postmortem examination. Other endogenous sources of emboli include the atheromatous debris, bone marrow, fat, liver, brain, trophoblast, and amniotic fluid. Exogenous (“foreign body”) emboli may be introduced during medical/surgical procedures or following penetrating trauma. Fatal intravenous air and gas emboli are also well documented. This report details the first case of a fatal suture embolism to the left anterior descending coronary artery following mitral valve replacement. The role of the medical examiner in the investigation of iatrogenic fatalities is discussed.

The clinical, histologic, and ultrastructural presentation of polyvinyl sponge (Ivalon) breast prostheses removed for massive fluid accumulation.

The current study describes what we believe is the first report of bilateral massive seromas associated with open-cell Ivalon sponges. Additionally, the gross, histologic, and ultrastructural features consistent with previous reports of polyvinyl alcohol prostheses are presented. Despite the reported chemical inertness of polyvinyl alcohol, this material may incite a biologic response in some patients, leading to dense fibrosis and occasional foreign-body giant-cell reaction. It is postulated that the molecular breakdown products of the polyvinyl alcohol polymer may create an osmotic gradient across the periprosthetic capsule, which may lead to intracapsular fluid accumulation, as presented in this case.

Silicone deposition in reconstruction scars of women with silicone breast implants

BACKGROUND The possible association of silicone breast implants and disease is a subject of continuous debate and concern. OBJECTIVE Our purpose was to examine microscopically and ultrastructurally the periprosthetic fibrous capsules and reconstruction scars of women with silicone breast implants. METHODS Representative samples from the periprosthetic capsules and reconstruction scars from six women with silicone breast implants were examined by a variety of light microscopy techniques, transmission electron microscopy, and electron probe microanalysis. RESULTS Silicone globules of various sizes were identified in every periprosthetic capsule and reconstruction scar. CONCLUSION Extrusion and seeding of the incision tract during surgery most likely accounts for the presence of silicone in the reconstruction scar specimens. This observation suggests that the identification of silicone in the reconstruction scars of women with silicone breast implants does not necessarily implicate rupture of the silicone breast implant with systemic dissemination of silicone gel.

Synovial metaplasia of a periprosthetic capsule surrounding a polyurethane foam breast prosthesis.

A 43-year-old woman underwent two-stage bilateral reconstruction mammoplasty using silicone-filled, polyurethane foam-covered breast implants. The permanent implants were later removed. The periprosthetic capsule demonstrated synovial metaplasia by light and electron microscopy. Synovial metaplasia is believed to be induced by the physical and chemical characteristics of the prostheses and may have important clinical implications in reducing capsular contracture and increasing host acceptance of implantable biomaterials.

Silicon Detection in Fat Globules in Pericapsular Tissue of Women and Rats Augmented with Silicone Gel

Abstract: Pericapsular adipose tissues of five patients with silicone gel breast implants were examined using electron probe microanalysis (EPMA), a sensitive method for detecting the elemental silicon component of silicone using transmission electron microscopy. All five patients had their implants removed secondary to implant complications. Five experimental animals that received subcutaneous silicone injections were also examined. Intracellular silicon was detected in the adipose tissue and in fat globules of macrophages in all patients and experimental animals. Three forms of intracellular silicon were identified: laminated, granular, and amorphous. No silicon was detected by EPMA in the adipose tissue of human and experimental animal controls. Potential origins of this silicon include the following: silicone gel (PDMS—Poly‐dimethylsiloxane), silicone gel that may have been converted to another form, and background silicon from food or environmental sources. The absence of detectable silicon in the control human and animal tissue implicates silicone gel as the probable source. To the best of our knowledge, this is the first description of intracellular silicon within fat globules of both adipocytes and macrophages in recipients of silicone breast implants.?