Implant Pathology



Implant Pathology












Thick fibrotic capsules form around breast implants and are associated with various types of foreign material. It may not be possible to determine the composition of many implants.






The large empty spaces are filled with refractile foreign material of uncertain type. There is a surrounding lymphocytic infiltrate.


TERMINOLOGY


Synonyms



  • Silicone implant


  • Saline implant


  • Tissue expanders


Definitions



  • Foreign material placed within chest wall to replace or enhance breast tissue



    • Some implants are placed between breast tissue and pectoral muscle


    • Subpectoral implants are placed between pectoral muscle and chest wall


ETIOLOGY/PATHOGENESIS


Types of Implants



  • Direct injection of substances has been used to augment breast size



    • Substances used have included organic oils, silicone, paraffin, and others


    • These substances usually migrate over time and result in a poor cosmetic appearance


    • This is not an accepted medical procedure


    • Foreign material can closely mimic a malignancy on breast imaging



      • Material may cause skin or nipple retraction and migrate to lymph nodes causing lymphadenopathy


  • Saline implants



    • These implants have thin silicone outer shell that is filled with saline


    • Some are intended for permanent use


    • Tissue expanders are temporary saline implants used prior to definitive breast reconstruction



      • Usually have a port that can be used to inject more saline


      • Implant is eventually replaced by permanent implant or by tissue reconstruction


    • If saline implant ruptures, there is immediate deflation and saline is quickly resorbed by surrounding tissue


  • Silicone implants



    • Silicone implants have thin silicone outer shell and are filled with silicone gel


    • These implants are intended for permanent use


    • If silicone implant ruptures, silicone is usually confined within surrounding fibrotic capsule



      • Imaging studies may be necessary to detect ruptured implant


  • Implants with polyurethane patches



    • Rough surfaced patches were used on some older implants to reduce effects of fibrotic response


    • Polyurethane has specific histologic appearance in capsular tissue


History of Breast Implants



  • 1st silicone shell implant was used in 1961


  • From 1992-2006, use of silicone implants was restricted to FDA-approved research projects due to safety concerns



    • Many well-publicized lawsuits were based on claims that implants were associated with autoimmune-type diseases


  • In 1999, National Institute of Medicine released a report stating that connective tissue disease was not more common in women with implants


  • In 2006, FDA lifted the moratorium on implants but did require follow-up studies of patients


  • In 1992, 32,000 women underwent augmentation procedures


  • In 2007, 347,000 underwent augmentation procedures


  • There are likely 2,000,000-5,000,000 women in USA currently with breast implants



CLINICAL ISSUES


Presentation



  • Infections associated with implants are rare



    • Most cases occur in perioperative period and are due to skin bacteria


    • In very rare cases, unusual organisms have been reported (fungi or mycobacteria)


Treatment



  • If contracture is pronounced, implant may need to be replaced to achieve acceptable cosmetic result



    • In the past, contractures were treated with pressure to “break” the capsule


    • This technique is no longer used as it may result in leakage of silicone into adjacent breast tissue


  • If infection occurs, implant must be removed


Complications and Treatment



  • Silicone implant rupture and migration of silicone



    • Silicone can “bleed” through intact implant shell and may be present in surrounding capsule



      • Silicone is usually restricted to capsule when implant is intact


    • If both implant and capsule are ruptured, silicone can migrate to distant sites



      • Most common site is regional lymph nodes


      • Silicone has also been reported to migrate to distant subcutaneous tissue and lung


  • Implant-associated lymphoma



    • May occur with both saline and silicone implants


    • Usually presents as implant complication, such as seroma or presumed infection


    • Presents 1-23 years after surgery


    • About 1/2 of patients have had cosmetic surgery and 1/2 breast reconstruction after breast cancer


    • Majority of implant-associated lymphomas arise from T cells



      • Only 10% of all primary breast lymphomas are T-cell lymphomas


      • 22 of 30 cases of primary breast anaplastic large cell lymphomas have been associated with implants


  • Implant-associated mesenchymal tumors

Jul 6, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Implant Pathology

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