+ MODEL Journal of the Formosan Medical Association (2016) xx, 1e2 Available online at www.sciencedirect.com ScienceDirect journal homepage: www.jfma-online.com CORRESPONDENCE Poly-L-lactic acid injection-induced delayed-onset foreign body granuloma Jang-Jaer Lee a,b, Yi-Ping Wang a,b,c, Yu-Hsueh Wu b, Julia Yu Fong Chang a,b,c,* a Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan b Department of Dentistry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan c Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan Received 20 November 2016; accepted 28 November 2016 Injection of various dermal fillers for cosmetic purpose is common and generally accepted as a safe and welltolerable procedure However, adverse reactions such as allergy, infection, and foreign body reaction sometimes occur Here, we report a case of delayed foreign body reaction to poly-L-lactic acid (PLLA) materials at a moderately distant location from the injection site where the patient had received injections of two different materials before This 54-year-old female patient found a painless soft tissue nodule in the left upper labial mucosa accidentally month ago Oral examination revealed a well-circumscribed, elastic to firm, submucosal nodule (measuring 1.2 cm  0.6 cm) in the left upper labial mucosa near the left upper lateral incisor and canine root apex (Figure 1A) No redness, local heat, or tenderness was noted Under the impression of a soft tissue tumor, a biopsy was performed The biopsy specimen showed a well-demarcated fibrous nodule (Figure 1B) composed of abundant flake-like transparent foreign materials engulfed by multinucleated giant cells and an infiltrate of scattered lymphocytes, histiocytes, and eosinophils in Conflicts of interest: The authors have no conflicts of interest relevant to this article * Corresponding author Department of Dentistry, National Taiwan University Hospital, Number 1, Chang-Te Street, Taipei 10048, Taiwan E-mail address: jyfchang@ntu.edu.tw (J.Y.F Chang) the submucosal soft tissue (Figure 1C) These flake-like transparent materials showed birefringence in polarized light (Figure 1D) A foreign body granuloma was diagnosed Based on our experience of diagnosis of a hyaluronic acidinduced foreign body granuloma case,1 knowledge from literature review,2 and the patient’s history of two injections of hyaluronic acid and PLLA (Sculptra; Dermik Laboratories, Inc., Bridgewater, NJ, USA) into the infrazygomatic cheek area several years ago, a PLLA injection-induced delayedonset foreign body granuloma at a moderately distant location from the injection site was further confirmed Since dermal fillers are generally thought to be safe and the injection procedures are quite easy, subcutaneous injection of different dermal fillers for cosmetic soft tissue augmentation has become popular recently However, a variety of adverse reactions including infection, allergy, and foreign body reaction occur over a wide range of time, which can be further divided into immediate-, early(within days), and delayed-onset (after weeks to years) reactions.1 Delayed reactions usually result in diagnostic problems because of long-standing durations and the distance between the swelling and the previous filler injection site PLLA is a synthetic and biodegradable polymer Initially, it was used in various maxillofacial and orthopedic procedures, and then it was used in correction of skin depression and facial lipoatrophy in human immunodeficiency virus-infected patients Delayed-onset inflammatory nodule formation is a quite common complication of PLLA injection.2 These palpable nodules can appear anywhere http://dx.doi.org/10.1016/j.jfma.2016.11.011 0929-6646/Copyright ª 2016, Formosan Medical Association Published by Elsevier Taiwan LLC This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Please cite this article in press as: Lee J-J, et al., Poly-L-lactic acid injection-induced delayed-onset foreign body granuloma, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.11.011 + MODEL J.-J Lee et al Figure Clinical photograph and histopathological and polarized-light microphotographs of a poly-L-lactic acid injectioninduced foreign body granuloma (A) A clinical photograph of the lesion showing a well-circumscribed nodule in the left upper labial mucosa (arrows) A gumboil at the alveolar mucosa of the left upper central incisor apical area was also noted (B) A gross photograph of the excised specimen exhibiting a well-demarcated nodule (C) A histopathological microphotograph of the lesion revealing abundant flake-like transparent foreign materials engulfed by multinucleated giant cells, and an infiltrate of scattered lymphocytes, histiocytes, and eosinophils in the fibrous stroma (hematoxylin and eosin stain, original magnification, 10Â) (D) A polarized-light microphotograph showing birefringent foreign materials in the granuloma tissue (original magnification, 10Â) and show relatively higher longevity compared with other temporary fillers, such as hyaluronic acid Surgical excision is the treatment of choice for these nodules Since some patients may receive injections multiple times and of different materials, as in this case, it is important to be familiar with the different histopathological findings of foreign body reactions induced by different materials Immunohistochemistry can be used to identify specific cells in various lesions.3e5 However, the diagnosis of PLLA injection-induced delayed-onset foreign body granuloma was mainly based on the history of PLLA injection and the specific histopathological findings rather than on immunohistochemistry References Tseng CH, Wang YP, Chen HM, Chang JYF Hyaluronic acid injection-induced delayed-onset foreign body granuloma J Dent Sci 2015;10:341e3 Rotunda AM, Narins RS Poly-L-lactic acid: a new dimension in soft tissue augmentation Dermatol Ther 2006;19:151e8 Tseng CH, Wang YP, Lee JJ, Chang JYF Noncalcifying variant of calcifying epithelial odontogenic tumor with Langerhans cells J Formos Med Assoc 2015;114:781e2 Wu YC, Chang JYF, Wang YP, Chiang CP Langerhans cells in keratoacanthoma J Formos Med Assoc 2015;114:475e6 Lin HP, Liu CJ, Chiang CP Spindle cell lipoma of the tongue J Formos Med Assoc 2015;114:477e9 Please cite this article in press as: Lee J-J, et al., Poly-L-lactic acid injection-induced delayed-onset foreign body granuloma, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.11.011 ...+ MODEL J.-J Lee et al Figure Clinical photograph and histopathological and polarized-light microphotographs of a poly- L- lactic acid injectioninduced foreign body granuloma (A) A clinical photograph... 2015;114:475e6 Lin HP, Liu CJ, Chiang CP Spindle cell lipoma of the tongue J Formos Med Assoc 2015;114:477e9 Please cite this article in press as: Lee J-J, et al., Poly- L- lactic acid injection- induced delayed- onset. .. Hyaluronic acid injection- induced delayed- onset foreign body granuloma J Dent Sci 2015;10:341e3 Rotunda AM, Narins RS Poly- L- lactic acid: a new dimension in soft tissue augmentation Dermatol Ther