Silicone lymphadenopathy mimicking a lymphoma in a patient with a metatarsophalangeal joint prosthesis

An evaluation of the host response to an interspinous process device based on a series of spine explants: Device for Intervertebral Assisted Motion (DIAM®)

Background

The objective of this study was to evaluate the host response to an interspinous process device [Device for Intervertebral Assisted Motion (DIAM^®)] based on a series of nine spine explants with a mean post-operative explant time of 35 months.

Methods

Explanted periprosthetic tissues were processed for histology and stained with H&E, Wright-Giemsa stain, and Oil Red O. Brightfield and polarized light microscopy were used to evaluate the host response to the device and the resultant particulate debris. The host response was graded per ASTM F981-04. Quantitative histomorphometry was used to characterize particle size, shape, and area per ASTM F1877-05. The presence or absence of bone resorption was also evaluated when bony tissue samples were provided.

Results

Periprosthetic tissues demonstrated a non-specific foreign body response composed of macrophages and foreign body giant cells to the DIAM^® device in most of the accessions. The foreign body reaction was not the stated reason for explantation in any of the accessions. Per ASTM F981-04, a "very slight" to "mild" to "moderate" chronic inflammatory response was observed to the biomaterials and particulate, and this varied by tissue sample and accession. Particle sizes were consistent amongst the explant patients with mean particle size on the order of several microns. Osteolysis, signs of toxicity, necrosis, an immune response, and/or device related infection were not observed.

Conclusions

Cyclic loading of the spine can cause wear in dynamic stabilization systems such as DIAM^®. The fabric nature of the DIAM^® device's polyethylene terephthalate jacket coupled with the generation of polymeric particulate debris predisposes the device to a foreign body reaction consisting of macrophages and foreign body giant cells. Although not all patients are aware of symptoms associated with a foreign body reaction to a deeply implanted device, surgeons should be aware of the host response to this device.

The foreign body response and morphometric changes associated with mesh-style peripheral nerve cuffs

Nerve cuffs have been used to anchor and protect penetrating electrodes in peripheral nerves and have been used as non-penetrating electrodes for neural recording and nerve stimulation. The material of choice for such applications is silicone, an inert synthetic biomaterial which elicits a minimal chronic foreign body response (FBR). While histological studies of solid silicone cuffs are available, to the best of our knowledge a comparison to other cuff designs is not well documented. Here, we describe the FBR and morphological changes that accompany nerve cuff implantation in the rat sciatic nerve by comparing a metallic mesh with and without a parylene coating to one made of silicone. Two months after implantation, we observed that such implants, irrespective of the cuff type, were associated with a persistent inflammatory response consisting of activated macrophages attached to the implant surfaces, which extended into the endoneurial space of the encapsulated nerve. We also observed foreign body giant cells in the epineurial space that were more prevalent in the mesh cohorts. The mesh cuff groups showed significant changes in several morphometric parameters that were not seen in the silicon group including reductions in nerve fiber packing density and a greater reduction of large diameter fibers. High magnification microscopy also showed greater evidence of foamy macrophages in the endoneurial space of the mesh implanted cohorts. Although the precise mechanisms are unknown, the results showed that mesh style nerve cuffs show a greater inflammatory response and had greater reductions in morphometric changes in the underlying nerve compared to silicone in the absence of a penetrating injury.

STATEMENT OF SIGNIFICANCE

While traditional silicone cuffs have been in use for decades, the inflammatory and morphometric effects of these cuffs on the underlying nerve have not been deeply studied. Further, manipulation of the foreign body response to nerve cuffs by using various materials and/or designs has not been well reported. Therefore, we report the inflammatory response around nerve cuffs of various materials and designs, as well as report morphometric parameters of the underlying nerve. These data provide important information regarding the potential for quantitative morphometric changes associated with the use of nerve cuffs, and, importantly, suggests that these changes are associated with the degree of inflammation associated with the cuff.

Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes

Benign and malignant proliferations of histiocytes and dendritic cells may be encountered in lymph nodes. Reactive histiocytic and dendritic cell infiltrates occur in response to diverse stimuli and in addition to causing lymphadenopathy, may be present unexpectedly in lymph nodes excised for other indications. This review summarizes the pathogenesis and histopathological features of the various non-neoplastic histiocytic and dendritic cell infiltrates that can occur in lymph nodes.

Silicone implants and lymphoma: The role of inflammation

The risk of hematological malignancies is mainly determined by genetic background, age, sex, race and ethnicity, geographic location, exposure to certain chemicals and radiation; along with the more recently proposed immune factors such as chronic inflammation, immunodeficiencies, autoimmunity, and infections. Paradigmatic examples include the development of lymphoma in Sjögren's syndrome and Hashimoto thyroiditis, gastric MALT lymphoma in Helicobacter pylori infection, or lymphomas associated with infections by Epstein-Barr virus, human herpes virus 8 (HHV 8) and leukemia/lymphoma virus 1 (HTLV-1). A growing number of reports indicates an increased risk of lymphoma, particularly of the anaplastic large cell (ALCL) type. The implants, specifically those used in the past, elicit chronic stimulation of the immune system against the prosthetic material. This is particularly the case in genetically susceptible hosts. We suggest that polyclonal activation may result in monoclonality in those at risk hosts, ultimately leading to lymphoma. We suggest that patients with an inflammatory response against silicone implants be monitored carefully.

Implants for the first metatarsophalangeal joint and prospective considerations

This article reviews the anatomy, pathology and biomechanics of the key joint of the foot, the first metatarsophalangeal joint, before focusing on the various designs of prosthesis that have been proposed for this joint. Metal hemiarthroplasties, single-piece, double-stem silicone implants and multicomponent implants are all considered in detail, as is an assessment of the available clinical results. In addition, preimplantation testing of the implants and the value of explant studies are discussed.

Neck lymphadenitis due to silicone granuloma after mammary implants

INTRODUCTION

A foreign body reaction due to silicone where it is infiltrated or at the places to which it can migrate is known as siliconoma. The use of silicone in breast augmentation procedures can provoke this reaction at the neck level in cases of leakage from mammary implants.

METHODS

We reviewed the cases of patients with increased size neck lymph nodes who had previously undergone plastic surgery of the breast with highly cohesive silicone gel implants.

RESULTS

In a 10-year period, we identified 12 cases with silicone-infiltrated neck lymphadenopathies, histologically confirmed by fine needle aspiration. They represented 3.5% of patients attended for neck lymph node study. We removed those detected by physical examination and CT in 5 cases, due to pathological characteristics of the node or a previous malignant history. In 2 of these nodes recurred, and node size also increased in 2 of the other 7 non-operated cases. After implant removal, silicone leakage was observed in only 7 cases.

CONCLUSIONS

Cohesive gel silicone used for mammary implants can generate increased neck lymphadenopathies as a secondary effect due to systemic reactions against the silicone when it migrates in cases of implant failure. Surgical options for involved nodes usually do not offer good long-term results.

The case against first metatarsal phalangeal joint implant arthroplasty

This article argues the practice of first metatarsal phalangeal joint (MPJ) implant arthroplasty. Intermediate and long-term studies raise concerns about implant failure and longevity. Other causes for concern are silicone-induced synovitis and lymphadenopathy. This article presents evidence against the practice of first metatarsal phalangeal implant arthroplasty. Intermediate and long-term studies raise concerns about implant failure and longevity. Furthermore, the lack of any significant long-term results and the documented metallic breakdown from two-piece metallic implants make their use in hallux rigidus questionable. Meanwhile, a comparative study shows the superiority of arthrodesis to implant arthroplasty. Also, alternatives to joint-destructive procedures are emerging. These include arthrodiastasis and the osteochondral autograft transfer procedure. This evidence proves that implant arthroplasty is not the best treatment for patients with hallux rigidus or other first-MPJ pathology.

Pathology of lymph nodes from patients with breast implants: a histologic and spectroscopic evaluation

There are only a few published reports describing the pathology of regional lymph nodes from patients with silicone breast implants. Systematic analytical chemical verification of foreign material has not previously been reported. In this study, biopsies of regional lymph nodes from 96 patients with breast implants were studied using conventional histology as well as laser-Raman microprobe spectroscopy and Fourier transform infrared microspectroscopy. Lymph nodes from 12 patients without implants served as negative controls. Foamy macrophages, ranging from rare scattered cells to confluent sheets, were observed in sections of lymph nodes from 91 patients with implants and only rare foamy macrophages were observed in sections from 4 patients without implants. Refractile material consistent with silicone was observed in sections from 86 patients with implants and in no sections from patients without implants. Fragments of foreign material consistent with polyurethane were observed in sections from 16 patients with implants and in no sections from patients without implants. Using spectroscopy, the presence of silicone was confirmed in 71 patients with implants, and the presence of polyurethane was confirmed in 2 patients with implants. Spectroscopy was negative for silicone and polyurethane in all patients without implants. In summary, regional lymph nodes from patients with breast implants often have histologic evidence of silicone migration. Characteristic histologic findings include foamy macrophages and refractile droplets of clear material. Polygonal fragments of polyurethane were observed in lymph nodes from a number of patients. This finding has not been previously reported. The presence of silicone and polyurethane was confirmed using confocal laser-Raman microprobe and Fourier transform infrared microspectroscopy. Other than two prior case reports, this is the first confirmatory evidence of silicone migration to lymph nodes in patients with breast implants and this is the first confirmatory report of polyurethane migration to lymph nodes.