British Journal of Oral and Maxillofacial Surgery 45 (2007) 228–230 Short communication Leiomyomatous hamartoma presenting as a congenital epulis Omar Kujan a , Stuart Clark b , Philip Sloan a,* a Unit of Oral Pathology, School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester, M15 6FH, UK b Unit of Oral Surgery, School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester, M15 6FH, UK Accepted 29 July 2005 Available online 12 September 2005 Abstract An otherwise-healthy 11-month-old white girl presented with a polyp-like lesion on the anteromedial part of the maxillary alveolar ridge. It looked like a congenital epulis, but histological examination showed fascicles of smooth muscle cells dispersed in collagenous stroma with a few peripheral nerve bundles that were intermingled with smooth muscle fibres. The muscle cells stained strongly for desmin and -smooth-muscle actin. However, S-100 was found only in peripheral nerve bundles. It was therefore a leiomyomatous hamartoma. © 2005 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Congenital; Leiomyomatous hamartoma; Epulis Introduction Congenital epulides usually occur in the anterior maxillary alveolus of baby girls, and the usual histological pattern is the granular cell type. 1 Other rare histological variants (fibrous and leiomyomatous) of congenital epulis have been reported. 2–4 We present a case of congenital leiomyomatous hamar- toma, with immunohistochemical findings, which presented as an epulis in a healthy 11-month-old girl. Case report An 11-month-old, otherwise-healthy girl was referred to the oral surgery out-patient clinic for investigation and manage- ment of a painless gingival polypoid mass on the anteromedial part of the maxillary alveolar ridge that had been present since birth and had slowly enlarged. We found a lobular, sessile, soft tissue polyp, roughly 10 mm long on the palatal side of the midline of the gingiva. * Corresponding author. Tel.: +44 161 275 6788; fax: +44 161 275 6797/6640. E-mail address: p.sloan@manchester.ac.uk (P. Sloan). The nodule was firm on palpation and was covered by normal mucosa. There were no palpable lymph nodes in the neck. The lesion was excised under local anaesthesia, and the specimen examined histologically. It measured 10 mm × 5 mm × 5 mm and had a greyish-white cut surface. It was embedded in paraf- fin, and sectioned for routine histopathological and immuno- histochemical staining. A standard indirect immunoperox- idase method with labelled streptavidin biotin (LSAB Kit, DAKO, Denmark) was used to stain for the following mark- ers: desmin (monoclonal; DAKO), -smooth-muscle actin (1:200 monoclonal; DAKO, Carpinteria, CA, USA), and S- 100 (1:2000 polyclonal; DAKO). Microscopy showed well-defined fascicles of smooth muscle cells intermingled with thick-walled blood vessels and a few nerve fibres. The islands of smooth muscle were dispersed in a fibrous stroma surrounding a central blood vessel. The covering epithelium was unremarkable (Fig. 1). There was no cytological atypia, and no granular cells or odontogenic epithelium in the lesion. Immunoperoxidase staining for desmin (Fig. 2A), and -smooth-muscle actin (Fig. 2B) showed large concentrations in the smooth muscle bundles. The hamartomatous smooth muscle fasicles stained more strongly for desmin than the vascular smooth muscle. However, S-100 was detected in only a few peripheral nerve bundles intermingled with smooth muscle fibres (Fig. 2C). 0266-4356/$ – see front matter © 2005 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjoms.2005.07.019